Webpack (#1367)

* Replace gulp with webpack and npm scripts for JS compilation
* Set up Travis CI to commit compiled JS
* Restructure `js` directory; only one instance of npm, forum/admin are "submodules"
* Refactor JS initializers into Application subclasses
* Maintain partial compatibility API (importing from absolute paths) for extensions
* Remove minification responsibility from PHP asset compiler
* Restructure `less` directory

js/src/admin/AdminApplication.js

@@ -0,0 +1,66 @@
+import HeaderPrimary from './components/HeaderPrimary';
+import HeaderSecondary from './components/HeaderSecondary';
+import routes from './routes';
+import Application from '../common/Application';
+import Navigation from '../common/components/Navigation';
+import AdminNav from './components/AdminNav';
+
+export default class AdminApplication extends Application {
+  extensionSettings = {};
+
+  history = {
+    canGoBack: () => true,
+    getPrevious: () => {},
+    backUrl: () => this.forum.attribute('baseUrl'),
+    back: function() {
+      window.location = this.backUrl();
+    }
+  };
+
+  /**
+   * @inheritdoc
+   */
+  boot(data) {
+    routes(this);
+
+    super.boot(data);
+  }
+
+  /**
+   * @inheritdoc
+   */
+  mount() {
+    m.mount(document.getElementById('app-navigation'), Navigation.component({className: 'App-backControl', drawer: true}));
+    m.mount(document.getElementById('header-navigation'), Navigation.component());
+    m.mount(document.getElementById('header-primary'), HeaderPrimary.component());
+    m.mount(document.getElementById('header-secondary'), HeaderSecondary.component());
+    m.mount(document.getElementById('admin-navigation'), AdminNav.component());
+
+    m.route.mode = 'hash';
+    super.mount();
+
+    // If an extension has just been enabled, then we will run its settings
+    // callback.
+    const enabled = localStorage.getItem('enabledExtension');
+    if (enabled && this.extensionSettings[enabled]) {
+      this.extensionSettings[enabled]();
+      localStorage.removeItem('enabledExtension');
+    }
+  }
+
+  getRequiredPermissions(permission) {
+    const required = [];
+
+    if (permission === 'startDiscussion' || permission.indexOf('discussion.') === 0) {
+      required.push('viewDiscussions');
+    }
+    if (permission === 'discussion.delete') {
+      required.push('discussion.hide');
+    }
+    if (permission === 'discussion.deletePosts') {
+      required.push('discussion.editPosts');
+    }
+
+    return required;
+  };
+}

js/src/admin/compat.js

@@ -0,0 +1,63 @@
+import compat from '../common/compat';
+
+import saveSettings from './utils/saveSettings';
+import SettingDropdown from './components/SettingDropdown';
+import EditCustomFooterModal from './components/EditCustomFooterModal';
+import SessionDropdown from './components/SessionDropdown';
+import HeaderPrimary from './components/HeaderPrimary';
+import AppearancePage from './components/AppearancePage';
+import Page from './components/Page';
+import StatusWidget from './components/StatusWidget';
+import HeaderSecondary from './components/HeaderSecondary';
+import SettingsModal from './components/SettingsModal';
+import DashboardWidget from './components/DashboardWidget';
+import AddExtensionModal from './components/AddExtensionModal';
+import ExtensionsPage from './components/ExtensionsPage';
+import AdminLinkButton from './components/AdminLinkButton';
+import PermissionGrid from './components/PermissionGrid';
+import Widget from './components/Widget';
+import MailPage from './components/MailPage';
+import UploadImageButton from './components/UploadImageButton';
+import LoadingModal from './components/LoadingModal';
+import DashboardPage from './components/DashboardPage';
+import BasicsPage from './components/BasicsPage';
+import EditCustomHeaderModal from './components/EditCustomHeaderModal';
+import PermissionsPage from './components/PermissionsPage';
+import PermissionDropdown from './components/PermissionDropdown';
+import AdminNav from './components/AdminNav';
+import EditCustomCssModal from './components/EditCustomCssModal';
+import EditGroupModal from './components/EditGroupModal';
+import routes from './routes';
+import AdminApplication from './AdminApplication';
+
+export default Object.assign(compat, {
+  'utils/saveSettings': saveSettings,
+  'components/SettingDropdown': SettingDropdown,
+  'components/EditCustomFooterModal': EditCustomFooterModal,
+  'components/SessionDropdown': SessionDropdown,
+  'components/HeaderPrimary': HeaderPrimary,
+  'components/AppearancePage': AppearancePage,
+  'components/Page': Page,
+  'components/StatusWidget': StatusWidget,
+  'components/HeaderSecondary': HeaderSecondary,
+  'components/SettingsModal': SettingsModal,
+  'components/DashboardWidget': DashboardWidget,
+  'components/AddExtensionModal': AddExtensionModal,
+  'components/ExtensionsPage': ExtensionsPage,
+  'components/AdminLinkButton': AdminLinkButton,
+  'components/PermissionGrid': PermissionGrid,
+  'components/Widget': Widget,
+  'components/MailPage': MailPage,
+  'components/UploadImageButton': UploadImageButton,
+  'components/LoadingModal': LoadingModal,
+  'components/DashboardPage': DashboardPage,
+  'components/BasicsPage': BasicsPage,
+  'components/EditCustomHeaderModal': EditCustomHeaderModal,
+  'components/PermissionsPage': PermissionsPage,
+  'components/PermissionDropdown': PermissionDropdown,
+  'components/AdminNav': AdminNav,
+  'components/EditCustomCssModal': EditCustomCssModal,
+  'components/EditGroupModal': EditGroupModal,
+  'routes': routes,
+  'AdminApplication': AdminApplication
+});

js/src/admin/components/AddExtensionModal.js

@@ -0,0 +1,30 @@
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+import Modal from '../../common/components/Modal';
+
+export default class AddExtensionModal extends Modal {
+  className() {
+    return 'AddExtensionModal Modal--small';
+  }
+
+  title() {
+    return app.translator.trans('core.admin.add_extension.title');
+  }
+
+  content() {
+    return (
+      <div className="Modal-body">
+        <p>{app.translator.trans('core.admin.add_extension.temporary_text')}</p>
+        <p>{app.translator.trans('core.admin.add_extension.install_text', {a: <a href="https://discuss.flarum.org/t/extensions" target="_blank"/>})}</p>
+        <p>{app.translator.trans('core.admin.add_extension.developer_text', {a: <a href="http://flarum.org/docs/extend" target="_blank"/>})}</p>
+      </div>
+    );
+  }
+}

js/src/admin/components/AdminLinkButton.js

@@ -0,0 +1,24 @@
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+import LinkButton from '../../common/components/LinkButton';
+
+export default class AdminLinkButton extends LinkButton {
+  getButtonContent() {
+    const content = super.getButtonContent();
+
+    content.push(
+      <div className="AdminLinkButton-description">
+        {this.props.description}
+      </div>
+    );
+
+    return content;
+  }
+}

js/src/admin/components/AdminNav.js

@@ -0,0 +1,78 @@
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+import Component from '../../common/Component';
+import AdminLinkButton from './AdminLinkButton';
+import SelectDropdown from '../../common/components/SelectDropdown';
+import ItemList from '../../common/utils/ItemList';
+
+export default class AdminNav extends Component {
+  view() {
+    return (
+      <SelectDropdown
+        className="AdminNav App-titleControl"
+        buttonClassName="Button">
+        {this.items().toArray()}
+      </SelectDropdown>
+    );
+  }
+
+  /**
+   * Build an item list of links to show in the admin navigation.
+   *
+   * @return {ItemList}
+   */
+  items() {
+    const items = new ItemList();
+
+    items.add('dashboard', AdminLinkButton.component({
+      href: app.route('dashboard'),
+      icon: 'far fa-chart-bar',
+      children: app.translator.trans('core.admin.nav.dashboard_button'),
+      description: app.translator.trans('core.admin.nav.dashboard_text')
+    }));
+
+    items.add('basics', AdminLinkButton.component({
+      href: app.route('basics'),
+      icon: 'fas fa-pencil-alt',
+      children: app.translator.trans('core.admin.nav.basics_button'),
+      description: app.translator.trans('core.admin.nav.basics_text')
+    }));
+
+    items.add('mail', AdminLinkButton.component({
+      href: app.route('mail'),
+      icon: 'fas fa-envelope',
+      children: app.translator.trans('core.admin.nav.email_button'),
+      description: app.translator.trans('core.admin.nav.email_text')
+    }));
+
+    items.add('permissions', AdminLinkButton.component({
+      href: app.route('permissions'),
+      icon: 'fas fa-key',
+      children: app.translator.trans('core.admin.nav.permissions_button'),
+      description: app.translator.trans('core.admin.nav.permissions_text')
+    }));
+
+    items.add('appearance', AdminLinkButton.component({
+      href: app.route('appearance'),
+      icon: 'fas fa-paint-brush',
+      children: app.translator.trans('core.admin.nav.appearance_button'),
+      description: app.translator.trans('core.admin.nav.appearance_text')
+    }));
+
+    items.add('extensions', AdminLinkButton.component({
+      href: app.route('extensions'),
+      icon: 'fas fa-puzzle-piece',
+      children: app.translator.trans('core.admin.nav.extensions_button'),
+      description: app.translator.trans('core.admin.nav.extensions_text')
+    }));
+
+    return items;
+  }
+}

js/src/admin/components/AppearancePage.js

@@ -0,0 +1,132 @@
+import Page from './Page';
+import Button from '../../common/components/Button';
+import Switch from '../../common/components/Switch';
+import EditCustomCssModal from './EditCustomCssModal';
+import EditCustomHeaderModal from './EditCustomHeaderModal';
+import EditCustomFooterModal from './EditCustomFooterModal';
+import UploadImageButton from './UploadImageButton';
+import saveSettings from '../utils/saveSettings';
+
+export default class AppearancePage extends Page {
+  init() {
+    super.init();
+
+    this.primaryColor = m.prop(app.data.settings.theme_primary_color);
+    this.secondaryColor = m.prop(app.data.settings.theme_secondary_color);
+    this.darkMode = m.prop(app.data.settings.theme_dark_mode === '1');
+    this.coloredHeader = m.prop(app.data.settings.theme_colored_header === '1');
+  }
+
+  view() {
+    return (
+      <div className="AppearancePage">
+        <div className="container">
+          <form onsubmit={this.onsubmit.bind(this)}>
+            <fieldset className="AppearancePage-colors">
+              <legend>{app.translator.trans('core.admin.appearance.colors_heading')}</legend>
+              <div className="helpText">
+                {app.translator.trans('core.admin.appearance.colors_text')}
+              </div>
+
+              <div className="AppearancePage-colors-input">
+                <input className="FormControl" type="text" placeholder="#aaaaaa" value={this.primaryColor()} onchange={m.withAttr('value', this.primaryColor)}/>
+                <input className="FormControl" type="text" placeholder="#aaaaaa" value={this.secondaryColor()} onchange={m.withAttr('value', this.secondaryColor)}/>
+              </div>
+
+              {Switch.component({
+                state: this.darkMode(),
+                children: app.translator.trans('core.admin.appearance.dark_mode_label'),
+                onchange: this.darkMode
+              })}
+
+              {Switch.component({
+                state: this.coloredHeader(),
+                children: app.translator.trans('core.admin.appearance.colored_header_label'),
+                onchange: this.coloredHeader
+              })}
+
+              {Button.component({
+                className: 'Button Button--primary',
+                type: 'submit',
+                children: app.translator.trans('core.admin.appearance.submit_button'),
+                loading: this.loading
+              })}
+            </fieldset>
+          </form>
+
+          <fieldset>
+            <legend>{app.translator.trans('core.admin.appearance.logo_heading')}</legend>
+            <div className="helpText">
+              {app.translator.trans('core.admin.appearance.logo_text')}
+            </div>
+            <UploadImageButton name="logo"/>
+          </fieldset>
+
+          <fieldset>
+            <legend>{app.translator.trans('core.admin.appearance.favicon_heading')}</legend>
+            <div className="helpText">
+              {app.translator.trans('core.admin.appearance.favicon_text')}
+            </div>
+            <UploadImageButton name="favicon"/>
+          </fieldset>
+
+          <fieldset>
+            <legend>{app.translator.trans('core.admin.appearance.custom_header_heading')}</legend>
+            <div className="helpText">
+              {app.translator.trans('core.admin.appearance.custom_header_text')}
+            </div>
+            {Button.component({
+              className: 'Button',
+              children: app.translator.trans('core.admin.appearance.edit_header_button'),
+              onclick: () => app.modal.show(new EditCustomHeaderModal())
+            })}
+          </fieldset>
+
+          <fieldset>
+            <legend>{app.translator.trans('core.admin.appearance.custom_footer_heading')}</legend>
+            <div className="helpText">
+              {app.translator.trans('core.admin.appearance.custom_footer_text')}
+            </div>
+            {Button.component({
+              className: 'Button',
+              children: app.translator.trans('core.admin.appearance.edit_footer_button'),
+              onclick: () => app.modal.show(new EditCustomFooterModal())
+            })}
+          </fieldset>
+
+          <fieldset>
+            <legend>{app.translator.trans('core.admin.appearance.custom_styles_heading')}</legend>
+            <div className="helpText">
+              {app.translator.trans('core.admin.appearance.custom_styles_text')}
+            </div>
+            {Button.component({
+              className: 'Button',
+              children: app.translator.trans('core.admin.appearance.edit_css_button'),
+              onclick: () => app.modal.show(new EditCustomCssModal())
+            })}
+          </fieldset>
+        </div>
+      </div>
+    );
+  }
+
+  onsubmit(e) {
+    e.preventDefault();
+
+    const hex = /^#[0-9a-f]{3}([0-9a-f]{3})?$/i;
+
+    if (!hex.test(this.primaryColor()) || !hex.test(this.secondaryColor())) {
+      alert(app.translator.trans('core.admin.appearance.enter_hex_message'));
+      return;
+    }
+
+    this.loading = true;
+
+    saveSettings({
+      theme_primary_color: this.primaryColor(),
+      theme_secondary_color: this.secondaryColor(),
+      theme_dark_mode: this.darkMode(),
+      theme_colored_header: this.coloredHeader()
+    }).then(() => window.location.reload());
+  }
+}

js/src/admin/components/BasicsPage.js

@@ -0,0 +1,166 @@
+import Page from './Page';
+import FieldSet from '../../common/components/FieldSet';
+import Select from '../../common/components/Select';
+import Button from '../../common/components/Button';
+import Alert from '../../common/components/Alert';
+import saveSettings from '../utils/saveSettings';
+import ItemList from '../../common/utils/ItemList';
+import Switch from '../../common/components/Switch';
+
+export default class BasicsPage extends Page {
+  init() {
+    super.init();
+
+    this.loading = false;
+
+    this.fields = [
+      'forum_title',
+      'forum_description',
+      'default_locale',
+      'show_language_selector',
+      'default_route',
+      'welcome_title',
+      'welcome_message'
+    ];
+    this.values = {};
+
+    const settings = app.data.settings;
+    this.fields.forEach(key => this.values[key] = m.prop(settings[key]));
+
+    this.localeOptions = {};
+    const locales = app.data.locales;
+    for (const i in locales) {
+      this.localeOptions[i] = `${locales[i]} (${i})`;
+    }
+
+    if (typeof this.values.show_language_selector() !== "number") this.values.show_language_selector(1);
+  }
+
+  view() {
+    return (
+      <div className="BasicsPage">
+        <div className="container">
+          <form onsubmit={this.onsubmit.bind(this)}>
+            {FieldSet.component({
+              label: app.translator.trans('core.admin.basics.forum_title_heading'),
+              children: [
+                <input className="FormControl" value={this.values.forum_title()} oninput={m.withAttr('value', this.values.forum_title)}/>
+              ]
+            })}
+
+            {FieldSet.component({
+              label: app.translator.trans('core.admin.basics.forum_description_heading'),
+              children: [
+                <div className="helpText">
+                  {app.translator.trans('core.admin.basics.forum_description_text')}
+                </div>,
+                <textarea className="FormControl" value={this.values.forum_description()} oninput={m.withAttr('value', this.values.forum_description)}/>
+              ]
+            })}
+
+            {Object.keys(this.localeOptions).length > 1
+              ? FieldSet.component({
+                label: app.translator.trans('core.admin.basics.default_language_heading'),
+                children: [
+                  Select.component({
+                    options: this.localeOptions,
+                    value: this.values.default_locale(),
+                    onchange: this.values.default_locale
+                  }),
+                  Switch.component({
+                    state: this.values.show_language_selector(),
+                    onchange: this.values.show_language_selector,
+                    children: app.translator.trans('core.admin.basics.show_language_selector_label'),
+                  })
+                ]
+              })
+              : ''}
+
+            {FieldSet.component({
+              label: app.translator.trans('core.admin.basics.home_page_heading'),
+              className: 'BasicsPage-homePage',
+              children: [
+                <div className="helpText">
+                  {app.translator.trans('core.admin.basics.home_page_text')}
+                </div>,
+                this.homePageItems().toArray().map(({path, label}) =>
+                  <label className="checkbox">
+                    <input type="radio" name="homePage" value={path} checked={this.values.default_route() === path} onclick={m.withAttr('value', this.values.default_route)}/>
+                    {label}
+                  </label>
+                )
+              ]
+            })}
+
+            {FieldSet.component({
+              label: app.translator.trans('core.admin.basics.welcome_banner_heading'),
+              className: 'BasicsPage-welcomeBanner',
+              children: [
+                <div className="helpText">
+                  {app.translator.trans('core.admin.basics.welcome_banner_text')}
+                </div>,
+                <div className="BasicsPage-welcomeBanner-input">
+                  <input className="FormControl" value={this.values.welcome_title()} oninput={m.withAttr('value', this.values.welcome_title)}/>
+                  <textarea className="FormControl" value={this.values.welcome_message()} oninput={m.withAttr('value', this.values.welcome_message)}/>
+                </div>
+              ]
+            })}
+
+            {Button.component({
+              type: 'submit',
+              className: 'Button Button--primary',
+              children: app.translator.trans('core.admin.basics.submit_button'),
+              loading: this.loading,
+              disabled: !this.changed()
+            })}
+          </form>
+        </div>
+      </div>
+    );
+  }
+
+  changed() {
+    return this.fields.some(key => this.values[key]() !== app.data.settings[key]);
+  }
+
+  /**
+   * Build a list of options for the default homepage. Each option must be an
+   * object with `path` and `label` properties.
+   *
+   * @return {ItemList}
+   * @public
+   */
+  homePageItems() {
+    const items = new ItemList();
+
+    items.add('allDiscussions', {
+      path: '/all',
+      label: app.translator.trans('core.admin.basics.all_discussions_label')
+    });
+
+    return items;
+  }
+
+  onsubmit(e) {
+    e.preventDefault();
+
+    if (this.loading) return;
+
+    this.loading = true;
+    app.alerts.dismiss(this.successAlert);
+
+    const settings = {};
+
+    this.fields.forEach(key => settings[key] = this.values[key]());
+
+    saveSettings(settings)
+      .then(() => {
+        app.alerts.show(this.successAlert = new Alert({type: 'success', children: app.translator.trans('core.admin.basics.saved_message')}));
+      })
+      .catch(() => {})
+      .then(() => {
+        this.loading = false;
+        m.redraw();
+      });
+  }
+}

js/src/admin/components/DashboardPage.js

@@ -0,0 +1,18 @@
+import Page from './Page';
+import StatusWidget from './StatusWidget';
+
+export default class DashboardPage extends Page {
+  view() {
+    return (
+      <div className="DashboardPage">
+        <div className="container">
+          {this.availableWidgets()}
+        </div>
+      </div>
+    );
+  }
+
+  availableWidgets() {
+    return [<StatusWidget/>];
+  }
+}

js/src/admin/components/DashboardWidget.js

@@ -0,0 +1,38 @@
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+import Component from '../../common/Component';
+
+export default class Widget extends Component {
+  view() {
+    return (
+      <div className={"Widget "+this.className()}>
+        {this.content()}
+      </div>
+    );
+  }
+
+  /**
+   * Get the class name to apply to the widget.
+   *
+   * @return {String}
+   */
+  className() {
+    return '';
+  }
+
+  /**
+   * Get the content of the widget.
+   *
+   * @return {VirtualElement}
+   */
+  content() {
+    return [];
+  }
+}

js/src/admin/components/EditCustomCssModal.js

@@ -0,0 +1,24 @@
+import SettingsModal from './SettingsModal';
+
+export default class EditCustomCssModal extends SettingsModal {
+  className() {
+    return 'EditCustomCssModal Modal--large';
+  }
+
+  title() {
+    return app.translator.trans('core.admin.edit_css.title');
+  }
+
+  form() {
+    return [
+      <p>{app.translator.trans('core.admin.edit_css.customize_text', {a: <a href="https://github.com/flarum/core/tree/master/less" target="_blank"/>})}</p>,
+      <div className="Form-group">
+        <textarea className="FormControl" rows="30" bidi={this.setting('custom_less')}/>
+      </div>
+    ];
+  }
+
+  onsaved() {
+    window.location.reload();
+  }
+}

js/src/admin/components/EditCustomFooterModal.js

@@ -0,0 +1,24 @@
+import SettingsModal from './SettingsModal';
+
+export default class EditCustomFooterModal extends SettingsModal {
+  className() {
+    return 'EditCustomFooterModal Modal--large';
+  }
+
+  title() {
+    return app.translator.trans('core.admin.edit_footer.title');
+  }
+
+  form() {
+    return [
+      <p>{app.translator.trans('core.admin.edit_footer.customize_text')}</p>,
+      <div className="Form-group">
+        <textarea className="FormControl" rows="30" bidi={this.setting('custom_footer')}/>
+      </div>
+    ];
+  }
+
+  onsaved() {
+    window.location.reload();
+  }
+}

js/src/admin/components/EditCustomHeaderModal.js

@@ -0,0 +1,24 @@
+import SettingsModal from './SettingsModal';
+
+export default class EditCustomHeaderModal extends SettingsModal {
+  className() {
+    return 'EditCustomHeaderModal Modal--large';
+  }
+
+  title() {
+    return app.translator.trans('core.admin.edit_header.title');
+  }
+
+  form() {
+    return [
+      <p>{app.translator.trans('core.admin.edit_header.customize_text')}</p>,
+      <div className="Form-group">
+        <textarea className="FormControl" rows="30" bidi={this.setting('custom_header')}/>
+      </div>
+    ];
+  }
+
+  onsaved() {
+    window.location.reload();
+  }
+}

js/src/admin/components/EditGroupModal.js

@@ -0,0 +1,102 @@
+import Modal from '../../common/components/Modal';
+import Button from '../../common/components/Button';
+import Badge from '../../common/components/Badge';
+import Group from '../../common/models/Group';
+
+/**
+ * The `EditGroupModal` component shows a modal dialog which allows the user
+ * to create or edit a group.
+ */
+export default class EditGroupModal extends Modal {
+  init() {
+    this.group = this.props.group || app.store.createRecord('groups');
+
+    this.nameSingular = m.prop(this.group.nameSingular() || '');
+    this.namePlural = m.prop(this.group.namePlural() || '');
+    this.icon = m.prop(this.group.icon() || '');
+    this.color = m.prop(this.group.color() || '');
+  }
+
+  className() {
+    return 'EditGroupModal Modal--small';
+  }
+
+  title() {
+    return [
+      this.color() || this.icon() ? Badge.component({
+        icon: this.icon(),
+        style: {backgroundColor: this.color()}
+      }) : '',
+      ' ',
+      this.namePlural() || app.translator.trans('core.admin.edit_group.title')
+    ];
+  }
+
+  content() {
+    return (
+      <div className="Modal-body">
+        <div className="Form">
+          <div className="Form-group">
+            <label>{app.translator.trans('core.admin.edit_group.name_label')}</label>
+            <div className="EditGroupModal-name-input">
+              <input className="FormControl" placeholder={app.translator.trans('core.admin.edit_group.singular_placeholder')} value={this.nameSingular()} oninput={m.withAttr('value', this.nameSingular)}/>
+              <input className="FormControl" placeholder={app.translator.trans('core.admin.edit_group.plural_placeholder')} value={this.namePlural()} oninput={m.withAttr('value', this.namePlural)}/>
+            </div>
+          </div>
+
+          <div className="Form-group">
+            <label>{app.translator.trans('core.admin.edit_group.color_label')}</label>
+            <input className="FormControl" placeholder="#aaaaaa" value={this.color()} oninput={m.withAttr('value', this.color)}/>
+          </div>
+
+          <div className="Form-group">
+            <label>{app.translator.trans('core.admin.edit_group.icon_label')}</label>
+            <div className="helpText">
+              {app.translator.trans('core.admin.edit_group.icon_text', {a: <a href="http://fortawesome.github.io/Font-Awesome/icons/" tabindex="-1"/>})}
+            </div>
+            <input className="FormControl" placeholder="bolt" value={this.icon()} oninput={m.withAttr('value', this.icon)}/>
+          </div>
+
+          <div className="Form-group">
+            {Button.component({
+              type: 'submit',
+              className: 'Button Button--primary EditGroupModal-save',
+              loading: this.loading,
+              children: app.translator.trans('core.admin.edit_group.submit_button')
+            })}
+            {this.group.exists && this.group.id() !== Group.ADMINISTRATOR_ID ? (
+              <button type="button" className="Button EditGroupModal-delete" onclick={this.deleteGroup.bind(this)}>
+                {app.translator.trans('core.admin.edit_group.delete_button')}
+              </button>
+            ) : ''}
+          </div>
+        </div>
+      </div>
+    );
+  }
+
+  onsubmit(e) {
+    e.preventDefault();
+
+    this.loading = true;
+
+    this.group.save({
+      nameSingular: this.nameSingular(),
+      namePlural: this.namePlural(),
+      color: this.color(),
+      icon: this.icon()
+    }, {errorHandler: this.onerror.bind(this)})
+      .then(this.hide.bind(this))
+      .catch(() => {
+        this.loading = false;
+        m.redraw();
+      });
+  }
+
+  deleteGroup() {
+    if (confirm(app.translator.trans('core.admin.edit_group.delete_confirmation'))) {
+      this.group.delete().then(() => m.redraw());
+      this.hide();
+    }
+  }
+}

js/src/admin/components/ExtensionsPage.js

@@ -0,0 +1,114 @@
+import Page from './Page';
+import LinkButton from '../../common/components/LinkButton';
+import Button from '../../common/components/Button';
+import Dropdown from '../../common/components/Dropdown';
+import Separator from '../../common/components/Separator';
+import AddExtensionModal from './AddExtensionModal';
+import LoadingModal from './LoadingModal';
+import ItemList from '../../common/utils/ItemList';
+import icon from '../../common/helpers/icon';
+import listItems from '../../common/helpers/listItems';
+
+export default class ExtensionsPage extends Page {
+  view() {
+    return (
+      <div className="ExtensionsPage">
+        <div className="ExtensionsPage-header">
+          <div className="container">
+            {Button.component({
+              children: app.translator.trans('core.admin.extensions.add_button'),
+              icon: 'fas fa-plus',
+              className: 'Button Button--primary',
+              onclick: () => app.modal.show(new AddExtensionModal())
+            })}
+          </div>
+        </div>
+
+        <div className="ExtensionsPage-list">
+          <div className="container">
+            <ul className="ExtensionList">
+              {Object.keys(app.data.extensions)
+                .map(id => {
+                  const extension = app.data.extensions[id];
+                  const controls = this.controlItems(extension.id).toArray();
+
+                  return <li className={'ExtensionListItem ' + (!this.isEnabled(extension.id) ? 'disabled' : '')}>
+                    <div className="ExtensionListItem-content">
+                      <span className="ExtensionListItem-icon ExtensionIcon" style={extension.icon}>
+                        {extension.icon ? icon(extension.icon.name) : ''}
+                      </span>
+                      {controls.length ? (
+                        <Dropdown
+                          className="ExtensionListItem-controls"
+                          buttonClassName="Button Button--icon Button--flat"
+                          menuClassName="Dropdown-menu--right"
+                          icon="fas fa-ellipsis-h">
+                          {controls}
+                        </Dropdown>
+                      ) : ''}
+                      <label className="ExtensionListItem-title">
+                        <input type="checkbox" checked={this.isEnabled(extension.id)} onclick={this.toggle.bind(this, extension.id)}/> {' '}
+                        {extension.extra['flarum-extension'].title}
+                      </label>
+                      <div className="ExtensionListItem-version">{extension.version}</div>
+                    </div>
+                  </li>;
+                })}
+            </ul>
+          </div>
+        </div>
+      </div>
+    );
+  }
+
+  controlItems(name) {
+    const items = new ItemList();
+    const enabled = this.isEnabled(name);
+
+    if (app.extensionSettings[name]) {
+      items.add('settings', Button.component({
+        icon: 'fas fa-cog',
+        children: app.translator.trans('core.admin.extensions.settings_button'),
+        onclick: app.extensionSettings[name]
+      }));
+    }
+
+    if (!enabled) {
+      items.add('uninstall', Button.component({
+        icon: 'far fa-trash-alt',
+        children: app.translator.trans('core.admin.extensions.uninstall_button'),
+        onclick: () => {
+          app.request({
+            url: app.forum.attribute('apiUrl') + '/extensions/' + name,
+            method: 'DELETE'
+          }).then(() => window.location.reload());
+
+          app.modal.show(new LoadingModal());
+        }
+      }));
+    }
+
+    return items;
+  }
+
+  isEnabled(name) {
+    const enabled = JSON.parse(app.data.settings.extensions_enabled);
+
+    return enabled.indexOf(name) !== -1;
+  }
+
+  toggle(id) {
+    const enabled = this.isEnabled(id);
+
+    app.request({
+      url: app.forum.attribute('apiUrl') + '/extensions/' + id,
+      method: 'PATCH',
+      data: {enabled: !enabled}
+    }).then(() => {
+      if (!enabled) localStorage.setItem('enabledExtension', id);
+      window.location.reload();
+    });
+
+    app.modal.show(new LoadingModal());
+  }
+}

js/src/admin/components/HeaderPrimary.js

@@ -0,0 +1,33 @@
+import Component from '../../common/Component';
+import ItemList from '../../common/utils/ItemList';
+import listItems from '../../common/helpers/listItems';
+
+/**
+ * The `HeaderPrimary` component displays primary header controls. On the
+ * default skin, these are shown just to the right of the forum title.
+ */
+export default class HeaderPrimary extends Component {
+  view() {
+    return (
+      <ul className="Header-controls">
+        {listItems(this.items().toArray())}
+      </ul>
+    );
+  }
+
+  config(isInitialized, context) {
+    // Since this component is 'above' the content of the page (that is, it is a
+    // part of the global UI that persists between routes), we will flag the DOM
+    // to be retained across route changes.
+    context.retain = true;
+  }
+
+  /**
+   * Build an item list for the controls.
+   *
+   * @return {ItemList}
+   */
+  items() {
+    return new ItemList();
+  }
+}

js/src/admin/components/HeaderSecondary.js

@@ -0,0 +1,37 @@
+import Component from '../../common/Component';
+import SessionDropdown from './SessionDropdown';
+import ItemList from '../../common/utils/ItemList';
+import listItems from '../../common/helpers/listItems';
+
+/**
+ * The `HeaderSecondary` component displays secondary header controls.
+ */
+export default class HeaderSecondary extends Component {
+  view() {
+    return (
+      <ul className="Header-controls">
+        {listItems(this.items().toArray())}
+      </ul>
+    );
+  }
+
+  config(isInitialized, context) {
+    // Since this component is 'above' the content of the page (that is, it is a
+    // part of the global UI that persists between routes), we will flag the DOM
+    // to be retained across route changes.
+    context.retain = true;
+  }
+
+  /**
+   * Build an item list for the controls.
+   *
+   * @return {ItemList}
+   */
+  items() {
+    const items = new ItemList();
+
+    items.add('session', SessionDropdown.component());
+
+    return items;
+  }
+}

js/src/admin/components/LoadingModal.js

@@ -0,0 +1,19 @@
+import Modal from '../../common/components/Modal';
+
+export default class LoadingModal extends Modal {
+  isDismissible() {
+    return false;
+  }
+
+  className() {
+    return 'LoadingModal Modal--small';
+  }
+
+  title() {
+    return app.translator.trans('core.admin.loading.title');
+  }
+
+  content() {
+    return '';
+  }
+}

js/src/admin/components/MailPage.js

@@ -0,0 +1,124 @@
+import Page from './Page';
+import FieldSet from '../../common/components/FieldSet';
+import Button from '../../common/components/Button';
+import Alert from '../../common/components/Alert';
+import saveSettings from '../utils/saveSettings';
+
+export default class MailPage extends Page {
+  init() {
+    super.init();
+
+    this.loading = false;
+
+    this.fields = [
+      'mail_driver',
+      'mail_host',
+      'mail_from',
+      'mail_port',
+      'mail_username',
+      'mail_password',
+      'mail_encryption'
+    ];
+    this.values = {};
+
+    const settings = app.data.settings;
+    this.fields.forEach(key => this.values[key] = m.prop(settings[key]));
+
+    this.localeOptions = {};
+    const locales = app.locales;
+    for (const i in locales) {
+      this.localeOptions[i] = `${locales[i]} (${i})`;
+    }
+  }
+
+  view() {
+    return (
+      <div className="MailPage">
+        <div className="container">
+          <form onsubmit={this.onsubmit.bind(this)}>
+            <h2>{app.translator.trans('core.admin.email.heading')}</h2>
+            <div className="helpText">
+              {app.translator.trans('core.admin.email.text')}
+            </div>
+
+            {FieldSet.component({
+              label: app.translator.trans('core.admin.email.server_heading'),
+              className: 'MailPage-MailSettings',
+              children: [
+                <div className="MailPage-MailSettings-input">
+                  <label>{app.translator.trans('core.admin.email.driver_label')}</label>
+                  <input className="FormControl" value={this.values.mail_driver() || ''} oninput={m.withAttr('value', this.values.mail_driver)} />
+                  <label>{app.translator.trans('core.admin.email.host_label')}</label>
+                  <input className="FormControl" value={this.values.mail_host() || ''} oninput={m.withAttr('value', this.values.mail_host)} />
+                  <label>{app.translator.trans('core.admin.email.port_label')}</label>
+                  <input className="FormControl" value={this.values.mail_port() || ''} oninput={m.withAttr('value', this.values.mail_port)} />
+                  <label>{app.translator.trans('core.admin.email.encryption_label')}</label>
+                  <input className="FormControl" value={this.values.mail_encryption() || ''} oninput={m.withAttr('value', this.values.mail_encryption)} />
+                </div>
+              ]
+            })}
+
+            {FieldSet.component({
+              label: app.translator.trans('core.admin.email.account_heading'),
+              className: 'MailPage-MailSettings',
+              children: [
+                <div className="MailPage-MailSettings-input">
+                  <label>{app.translator.trans('core.admin.email.username_label')}</label>
+                  <input className="FormControl" value={this.values.mail_username() || ''} oninput={m.withAttr('value', this.values.mail_username)} />
+                  <label>{app.translator.trans('core.admin.email.password_label')}</label>
+                  <input className="FormControl" value={this.values.mail_password() || ''} oninput={m.withAttr('value', this.values.mail_password)} />
+                </div>
+              ]
+            })}
+
+            {FieldSet.component({
+              label: app.translator.trans('core.admin.email.addresses_heading'),
+              className: 'MailPage-MailSettings',
+              children: [
+                <div className="MailPage-MailSettings-input">
+                  <label>{app.translator.trans('core.admin.email.from_label')}</label>
+                  <input className="FormControl" value={this.values.mail_from() || ''} oninput={m.withAttr('value', this.values.mail_from)} />
+                </div>
+              ]
+            })}
+
+            {Button.component({
+              type: 'submit',
+              className: 'Button Button--primary',
+              children: app.translator.trans('core.admin.email.submit_button'),
+              loading: this.loading,
+              disabled: !this.changed()
+            })}
+          </form>
+        </div>
+      </div>
+    );
+  }
+
+  changed() {
+    return this.fields.some(key => this.values[key]() !== app.data.settings[key]);
+  }
+
+  onsubmit(e) {
+    e.preventDefault();
+
+    if (this.loading) return;
+
+    this.loading = true;
+    app.alerts.dismiss(this.successAlert);
+
+    const settings = {};
+
+    this.fields.forEach(key => settings[key] = this.values[key]());
+
+    saveSettings(settings)
+      .then(() => {
+        app.alerts.show(this.successAlert = new Alert({type: 'success', children: app.translator.trans('core.admin.basics.saved_message')}));
+      })
+      .catch(() => {})
+      .then(() => {
+        this.loading = false;
+        m.redraw();
+      });
+  }
+}

js/src/admin/components/Page.js

@@ -0,0 +1,32 @@
+import Component from '../../common/Component';
+
+/**
+ * The `Page` component
+ *
+ * @abstract
+ */
+export default class Page extends Component {
+  init() {
+    app.previous = app.current;
+    app.current = this;
+
+    app.modal.close();
+
+    /**
+     * A class name to apply to the body while the route is active.
+     *
+     * @type {String}
+     */
+    this.bodyClass = '';
+  }
+
+  config(isInitialized, context) {
+    if (isInitialized) return;
+
+    if (this.bodyClass) {
+      $('#app').addClass(this.bodyClass);
+
+      context.onunload = () => $('#app').removeClass(this.bodyClass);
+    }
+  }
+}

js/src/admin/components/PermissionDropdown.js

@@ -0,0 +1,149 @@
+import Dropdown from '../../common/components/Dropdown';
+import Button from '../../common/components/Button';
+import Separator from '../../common/components/Separator';
+import Group from '../../common/models/Group';
+import Badge from '../../common/components/Badge';
+import GroupBadge from '../../common/components/GroupBadge';
+
+function badgeForId(id) {
+  const group = app.store.getById('groups', id);
+
+  return group ? GroupBadge.component({group, label: null}) : '';
+}
+
+function filterByRequiredPermissions(groupIds, permission) {
+  app.getRequiredPermissions(permission)
+    .forEach(required => {
+      const restrictToGroupIds = app.data.permissions[required] || [];
+
+      if (restrictToGroupIds.indexOf(Group.GUEST_ID) !== -1) {
+        // do nothing
+      } else if (restrictToGroupIds.indexOf(Group.MEMBER_ID) !== -1) {
+        groupIds = groupIds.filter(id => id !== Group.GUEST_ID);
+      } else if (groupIds.indexOf(Group.MEMBER_ID) !== -1) {
+        groupIds = restrictToGroupIds;
+      } else {
+        groupIds = restrictToGroupIds.filter(id => groupIds.indexOf(id) !== -1);
+      }
+
+      groupIds = filterByRequiredPermissions(groupIds, required);
+    });
+
+  return groupIds;
+}
+
+export default class PermissionDropdown extends Dropdown {
+  static initProps(props) {
+    super.initProps(props);
+
+    props.className = 'PermissionDropdown';
+    props.buttonClassName = 'Button Button--text';
+  }
+
+  view() {
+    this.props.children = [];
+
+    let groupIds = app.data.permissions[this.props.permission] || [];
+
+    groupIds = filterByRequiredPermissions(groupIds, this.props.permission);
+
+    const everyone = groupIds.indexOf(Group.GUEST_ID) !== -1;
+    const members = groupIds.indexOf(Group.MEMBER_ID) !== -1;
+    const adminGroup = app.store.getById('groups', Group.ADMINISTRATOR_ID);
+
+    if (everyone) {
+      this.props.label = Badge.component({icon: 'fas fa-globe'});
+    } else if (members) {
+      this.props.label = Badge.component({icon: 'fas fa-user'});
+    } else {
+      this.props.label = [
+        badgeForId(Group.ADMINISTRATOR_ID),
+        groupIds.map(badgeForId)
+      ];
+    }
+
+    if (this.showing) {
+      if (this.props.allowGuest) {
+        this.props.children.push(
+          Button.component({
+            children: [Badge.component({icon: 'fas fa-globe'}), ' ', app.translator.trans('core.admin.permissions_controls.everyone_button')],
+            icon: everyone ? 'fas fa-check' : true,
+            onclick: () => this.save([Group.GUEST_ID]),
+            disabled: this.isGroupDisabled(Group.GUEST_ID)
+          })
+        );
+      }
+
+      this.props.children.push(
+        Button.component({
+          children: [Badge.component({icon: 'fas fa-user'}), ' ', app.translator.trans('core.admin.permissions_controls.members_button')],
+          icon: members ? 'fas fa-check' : true,
+          onclick: () => this.save([Group.MEMBER_ID]),
+          disabled: this.isGroupDisabled(Group.MEMBER_ID)
+        }),
+
+        Separator.component(),
+
+        Button.component({
+          children: [badgeForId(adminGroup.id()), ' ', adminGroup.namePlural()],
+          icon: !everyone && !members ? 'fas fa-check' : true,
+          disabled: !everyone && !members,
+          onclick: e => {
+            if (e.shiftKey) e.stopPropagation();
+            this.save([]);
+          }
+        })
+      );
+
+      [].push.apply(
+        this.props.children,
+        app.store.all('groups')
+          .filter(group => [Group.ADMINISTRATOR_ID, Group.GUEST_ID, Group.MEMBER_ID].indexOf(group.id()) === -1)
+          .map(group => Button.component({
+            children: [badgeForId(group.id()), ' ', group.namePlural()],
+            icon: groupIds.indexOf(group.id()) !== -1 ? 'fas fa-check' : true,
+            onclick: (e) => {
+              if (e.shiftKey) e.stopPropagation();
+              this.toggle(group.id());
+            },
+            disabled: this.isGroupDisabled(group.id()) && this.isGroupDisabled(Group.MEMBER_ID) && this.isGroupDisabled(Group.GUEST_ID)
+          }))
+      );
+    }
+
+    return super.view();
+  }
+
+  save(groupIds) {
+    const permission = this.props.permission;
+
+    app.data.permissions[permission] = groupIds;
+
+    app.request({
+      method: 'POST',
+      url: app.forum.attribute('apiUrl') + '/permission',
+      data: {permission, groupIds}
+    });
+  }
+
+  toggle(groupId) {
+    const permission = this.props.permission;
+
+    let groupIds = app.data.permissions[permission] || [];
+
+    const index = groupIds.indexOf(groupId);
+
+    if (index !== -1) {
+      groupIds.splice(index, 1);
+    } else {
+      groupIds.push(groupId);
+      groupIds = groupIds.filter(id => [Group.GUEST_ID, Group.MEMBER_ID].indexOf(id) === -1);
+    }
+
+    this.save(groupIds);
+  }
+
+  isGroupDisabled(id) {
+    return filterByRequiredPermissions([id], this.props.permission).indexOf(id) === -1;
+  }
+}

js/src/admin/components/PermissionGrid.js

@@ -0,0 +1,247 @@
+import Component from '../../common/Component';
+import PermissionDropdown from './PermissionDropdown';
+import SettingDropdown from './SettingDropdown';
+import Button from '../../common/components/Button';
+import ItemList from '../../common/utils/ItemList';
+import icon from '../../common/helpers/icon';
+
+export default class PermissionGrid extends Component {
+  init() {
+    this.permissions = this.permissionItems().toArray();
+  }
+
+  view() {
+    const scopes = this.scopeItems().toArray();
+
+    const permissionCells = permission => {
+      return scopes.map(scope => (
+        <td>
+          {scope.render(permission)}
+        </td>
+      ));
+    };
+
+    return (
+      <table className="PermissionGrid">
+        <thead>
+          <tr>
+            <td></td>
+            {scopes.map(scope => (
+              <th>
+                {scope.label}{' '}
+                {scope.onremove ? Button.component({icon: 'fas fa-times', className: 'Button Button--text PermissionGrid-removeScope', onclick: scope.onremove}) : ''}
+              </th>
+            ))}
+            <th>{this.scopeControlItems().toArray()}</th>
+          </tr>
+        </thead>
+        {this.permissions.map(section => (
+          <tbody>
+            <tr className="PermissionGrid-section">
+              <th>{section.label}</th>
+              {permissionCells(section)}
+              <td/>
+            </tr>
+            {section.children.map(child => (
+              <tr className="PermissionGrid-child">
+                <th>{icon(child.icon)}{child.label}</th>
+                {permissionCells(child)}
+                <td/>
+              </tr>
+            ))}
+          </tbody>
+        ))}
+      </table>
+    );
+  }
+
+  permissionItems() {
+    const items = new ItemList();
+
+    items.add('view', {
+      label: app.translator.trans('core.admin.permissions.read_heading'),
+      children: this.viewItems().toArray()
+    }, 100);
+
+    items.add('start', {
+      label: app.translator.trans('core.admin.permissions.create_heading'),
+      children: this.startItems().toArray()
+    }, 90);
+
+    items.add('reply', {
+      label: app.translator.trans('core.admin.permissions.participate_heading'),
+      children: this.replyItems().toArray()
+    }, 80);
+
+    items.add('moderate', {
+      label: app.translator.trans('core.admin.permissions.moderate_heading'),
+      children: this.moderateItems().toArray()
+    }, 70);
+
+    return items;
+  }
+
+  viewItems() {
+    const items = new ItemList();
+
+    items.add('viewDiscussions', {
+      icon: 'fas fa-eye',
+      label: app.translator.trans('core.admin.permissions.view_discussions_label'),
+      permission: 'viewDiscussions',
+      allowGuest: true
+    }, 100);
+
+    items.add('viewUserList', {
+      icon: 'fas fa-users',
+      label: app.translator.trans('core.admin.permissions.view_user_list_label'),
+      permission: 'viewUserList',
+      allowGuest: true
+    }, 100);
+
+    items.add('signUp', {
+      icon: 'fas fa-user-plus',
+      label: app.translator.trans('core.admin.permissions.sign_up_label'),
+      setting: () => SettingDropdown.component({
+        key: 'allow_sign_up',
+        options: [
+          {value: '1', label: app.translator.trans('core.admin.permissions_controls.signup_open_button')},
+          {value: '0', label: app.translator.trans('core.admin.permissions_controls.signup_closed_button')}
+        ]
+      })
+    }, 90);
+
+    return items;
+  }
+
+  startItems() {
+    const items = new ItemList();
+
+    items.add('start', {
+      icon: 'fas fa-edit',
+      label: app.translator.trans('core.admin.permissions.start_discussions_label'),
+      permission: 'startDiscussion'
+    }, 100);
+
+    items.add('allowRenaming', {
+      icon: 'fas fa-i-cursor',
+      label: app.translator.trans('core.admin.permissions.allow_renaming_label'),
+      setting: () => {
+        const minutes = parseInt(app.data.settings.allow_renaming, 10);
+
+        return SettingDropdown.component({
+          defaultLabel: minutes
+            ? app.translator.transChoice('core.admin.permissions_controls.allow_some_minutes_button', minutes, {count: minutes})
+            : app.translator.trans('core.admin.permissions_controls.allow_indefinitely_button'),
+          key: 'allow_renaming',
+          options: [
+            {value: '-1', label: app.translator.trans('core.admin.permissions_controls.allow_indefinitely_button')},
+            {value: '10', label: app.translator.trans('core.admin.permissions_controls.allow_ten_minutes_button')},
+            {value: 'reply', label: app.translator.trans('core.admin.permissions_controls.allow_until_reply_button')}
+          ]
+        });
+      }
+    }, 90);
+
+    return items;
+  }
+
+  replyItems() {
+    const items = new ItemList();
+
+    items.add('reply', {
+      icon: 'fas fa-reply',
+      label: app.translator.trans('core.admin.permissions.reply_to_discussions_label'),
+      permission: 'discussion.reply'
+    }, 100);
+
+    items.add('allowPostEditing', {
+      icon: 'fas fa-pencil-alt',
+      label: app.translator.trans('core.admin.permissions.allow_post_editing_label'),
+      setting: () => {
+        const minutes = parseInt(app.data.settings.allow_post_editing, 10);
+
+        return SettingDropdown.component({
+          defaultLabel: minutes
+            ? app.translator.transChoice('core.admin.permissions_controls.allow_some_minutes_button', minutes, {count: minutes})
+            : app.translator.trans('core.admin.permissions_controls.allow_indefinitely_button'),
+          key: 'allow_post_editing',
+          options: [
+            {value: '-1', label: app.translator.trans('core.admin.permissions_controls.allow_indefinitely_button')},
+            {value: '10', label: app.translator.trans('core.admin.permissions_controls.allow_ten_minutes_button')},
+            {value: 'reply', label: app.translator.trans('core.admin.permissions_controls.allow_until_reply_button')}
+          ]
+        });
+      }
+    }, 90);
+
+    return items;
+  }
+
+  moderateItems() {
+    const items = new ItemList();
+
+    items.add('viewIpsPosts', {
+      icon: 'fas fa-bullseye',
+      label: app.translator.trans('core.admin.permissions.view_post_ips_label'),
+      permission: 'discussion.viewIpsPosts'
+    }, 110);
+
+    items.add('renameDiscussions', {
+      icon: 'fas fa-i-cursor',
+      label: app.translator.trans('core.admin.permissions.rename_discussions_label'),
+      permission: 'discussion.rename'
+    }, 100);
+
+    items.add('hideDiscussions', {
+      icon: 'far fa-trash-alt',
+      label: app.translator.trans('core.admin.permissions.delete_discussions_label'),
+      permission: 'discussion.hide'
+    }, 90);
+
+    items.add('deleteDiscussions', {
+      icon: 'fas fa-times',
+      label: app.translator.trans('core.admin.permissions.delete_discussions_forever_label'),
+      permission: 'discussion.delete'
+    }, 80);
+
+    items.add('editPosts', {
+      icon: 'fas fa-pencil-alt',
+      label: app.translator.trans('core.admin.permissions.edit_and_delete_posts_label'),
+      permission: 'discussion.editPosts'
+    }, 70);
+
+    items.add('deletePosts', {
+      icon: 'fas fa-times',
+      label: app.translator.trans('core.admin.permissions.delete_posts_forever_label'),
+      permission: 'discussion.deletePosts'
+    }, 60);
+
+    return items;
+  }
+
+  scopeItems() {
+    const items = new ItemList();
+
+    items.add('global', {
+      label: app.translator.trans('core.admin.permissions.global_heading'),
+      render: item => {
+        if (item.setting) {
+          return item.setting();
+        } else if (item.permission) {
+          return PermissionDropdown.component({
+            permission: item.permission,
+            allowGuest: item.allowGuest
+          });
+        }
+
+        return '';
+      }
+    }, 100);
+
+    return items;
+  }
+
+  scopeControlItems() {
+    return new ItemList();
+  }
+}

js/src/admin/components/PermissionsPage.js

@@ -0,0 +1,41 @@
+import Page from './Page';
+import GroupBadge from '../../common/components/GroupBadge';
+import EditGroupModal from './EditGroupModal';
+import Group from '../../common/models/Group';
+import icon from '../../common/helpers/icon';
+import PermissionGrid from './PermissionGrid';
+
+export default class PermissionsPage extends Page {
+  view() {
+    return (
+      <div className="PermissionsPage">
+        <div className="PermissionsPage-groups">
+          <div className="container">
+            {app.store.all('groups')
+              .filter(group => [Group.GUEST_ID, Group.MEMBER_ID].indexOf(group.id()) === -1)
+              .map(group => (
+                <button className="Button Group" onclick={() => app.modal.show(new EditGroupModal({group}))}>
+                  {GroupBadge.component({
+                    group,
+                    className: 'Group-icon',
+                    label: null
+                  })}
+                  <span className="Group-name">{group.namePlural()}</span>
+                </button>
+              ))}
+            <button className="Button Group Group--add" onclick={() => app.modal.show(new EditGroupModal())}>
+              {icon('fas fa-plus', {className: 'Group-icon'})}
+              <span className="Group-name">{app.translator.trans('core.admin.permissions.new_group_button')}</span>
+            </button>
+          </div>
+        </div>
+
+        <div className="PermissionsPage-permissions">
+          <div className="container">
+            {PermissionGrid.component()}
+          </div>
+        </div>
+      </div>
+    );
+  }
+}

js/src/admin/components/SessionDropdown.js

@@ -0,0 +1,54 @@
+import avatar from '../../common/helpers/avatar';
+import username from '../../common/helpers/username';
+import Dropdown from '../../common/components/Dropdown';
+import Button from '../../common/components/Button';
+import ItemList from '../../common/utils/ItemList';
+
+/**
+ * The `SessionDropdown` component shows a button with the current user's
+ * avatar/name, with a dropdown of session controls.
+ */
+export default class SessionDropdown extends Dropdown {
+  static initProps(props) {
+    super.initProps(props);
+
+    props.className = 'SessionDropdown';
+    props.buttonClassName = 'Button Button--user Button--flat';
+    props.menuClassName = 'Dropdown-menu--right';
+  }
+
+  view() {
+    this.props.children = this.items().toArray();
+
+    return super.view();
+  }
+
+  getButtonContent() {
+    const user = app.session.user;
+
+    return [
+      avatar(user), ' ',
+      <span className="Button-label">{username(user)}</span>
+    ];
+  }
+
+  /**
+   * Build an item list for the contents of the dropdown menu.
+   *
+   * @return {ItemList}
+   */
+  items() {
+    const items = new ItemList();
+
+    items.add('logOut',
+      Button.component({
+        icon: 'fas fa-sign-out-alt',
+        children: app.translator.trans('core.admin.header.log_out_button'),
+        onclick: app.session.logout.bind(app.session)
+      }),
+      -100
+    );
+
+    return items;
+  }
+}

js/src/admin/components/SettingDropdown.js

@@ -0,0 +1,25 @@
+import SelectDropdown from '../../common/components/SelectDropdown';
+import Button from '../../common/components/Button';
+import saveSettings from '../utils/saveSettings';
+
+export default class SettingDropdown extends SelectDropdown {
+  static initProps(props) {
+    super.initProps(props);
+
+    props.className = 'SettingDropdown';
+    props.buttonClassName = 'Button Button--text';
+    props.caretIcon = 'fas fa-caret-down';
+    props.defaultLabel = 'Custom';
+
+    props.children = props.options.map(({value, label}) => {
+      const active = app.data.settings[props.key] === value;
+
+      return Button.component({
+        children: label,
+        icon: active ? 'fas fa-check' : true,
+        onclick: saveSettings.bind(this, {[props.key]: value}),
+        active
+      });
+    });
+  }
+}

js/src/admin/components/SettingsModal.js

@@ -0,0 +1,79 @@
+import Modal from '../../common/components/Modal';
+import Button from '../../common/components/Button';
+import saveSettings from '../utils/saveSettings';
+
+export default class SettingsModal extends Modal {
+  init() {
+    this.settings = {};
+    this.loading = false;
+  }
+
+  form() {
+    return '';
+  }
+
+  content() {
+    return (
+      <div className="Modal-body">
+        <div className="Form">
+          {this.form()}
+
+          <div className="Form-group">
+            {this.submitButton()}
+          </div>
+        </div>
+      </div>
+    );
+  }
+
+  submitButton() {
+    return (
+      <Button
+        type="submit"
+        className="Button Button--primary"
+        loading={this.loading}
+        disabled={!this.changed()}>
+        {app.translator.trans('core.admin.settings.submit_button')}
+      </Button>
+    );
+  }
+
+  setting(key, fallback = '') {
+    this.settings[key] = this.settings[key] || m.prop(app.data.settings[key] || fallback);
+
+    return this.settings[key];
+  }
+
+  dirty() {
+    const dirty = {};
+
+    Object.keys(this.settings).forEach(key => {
+      const value = this.settings[key]();
+
+      if (value !== app.data.settings[key]) {
+        dirty[key] = value;
+      }
+    });
+
+    return dirty;
+  }
+
+  changed() {
+    return Object.keys(this.dirty()).length;
+  }
+
+  onsubmit(e) {
+    e.preventDefault();
+
+    this.loading = true;
+
+    saveSettings(this.dirty()).then(
+      this.onsaved.bind(this),
+      this.loaded.bind(this)
+    );
+  }
+
+  onsaved() {
+    this.hide();
+  }
+}

js/src/admin/components/StatusWidget.js

@@ -0,0 +1,41 @@
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+import DashboardWidget from './DashboardWidget';
+import icon from '../../common/helpers/icon';
+import listItems from '../../common/helpers/listItems';
+import ItemList from '../../common/utils/ItemList';
+
+export default class StatusWidget extends DashboardWidget {
+  className() {
+    return 'StatusWidget';
+  }
+
+  content() {
+    return (
+      <ul>{listItems(this.items().toArray())}</ul>
+    );
+  }
+
+  items() {
+    const items = new ItemList();
+
+    items.add('help', (
+      <a href="http://flarum.org/docs/troubleshooting" target="_blank">
+        {icon('fas fa-question-circle')} {app.translator.trans('core.admin.dashboard.help_link')}
+      </a>
+    ));
+
+    items.add('version-flarum', [<strong>Flarum</strong>, <br/>, app.forum.attribute('version')]);
+    items.add('version-php', [<strong>PHP</strong>, <br/>, app.data.phpVersion]);
+    items.add('version-mysql', [<strong>MySQL</strong>, <br/>, app.data.mysqlVersion]);
+
+    return items;
+  }
+}

js/src/admin/components/UploadImageButton.js

@@ -0,0 +1,97 @@
+import Button from '../../common/components/Button';
+
+export default class UploadImageButton extends Button {
+  init() {
+    this.loading = false;
+  }
+
+  view() {
+    this.props.loading = this.loading;
+    this.props.className = (this.props.className || '') + ' Button';
+
+    if (app.data.settings[this.props.name + '_path']) {
+      this.props.onclick = this.remove.bind(this);
+      this.props.children = app.translator.trans('core.admin.upload_image.remove_button');
+
+      return (
+        <div>
+          <p><img src={app.forum.attribute(this.props.name+'Url')} alt=""/></p>
+          <p>{super.view()}</p>
+        </div>
+      );
+    } else {
+      this.props.onclick = this.upload.bind(this);
+      this.props.children = app.translator.trans('core.admin.upload_image.upload_button');
+    }
+
+    return super.view();
+  }
+
+  /**
+   * Prompt the user to upload an image.
+   */
+  upload() {
+    if (this.loading) return;
+
+    const $input = $('<input type="file">');
+
+    $input.appendTo('body').hide().click().on('change', e => {
+      const data = new FormData();
+      data.append(this.props.name, $(e.target)[0].files[0]);
+
+      this.loading = true;
+      m.redraw();
+
+      app.request({
+        method: 'POST',
+        url: this.resourceUrl(),
+        serialize: raw => raw,
+        data
+      }).then(
+        this.success.bind(this),
+        this.failure.bind(this)
+      );
+    });
+  }
+
+  /**
+   * Remove the logo.
+   */
+  remove() {
+    this.loading = true;
+    m.redraw();
+
+    app.request({
+      method: 'DELETE',
+      url: this.resourceUrl()
+    }).then(
+      this.success.bind(this),
+      this.failure.bind(this)
+    );
+  }
+
+  resourceUrl() {
+    return app.forum.attribute('apiUrl') + '/' + this.props.name;
+  }
+
+  /**
+   * After a successful upload/removal, reload the page.
+   *
+   * @param {Object} response
+   * @protected
+   */
+  success(response) {
+    window.location.reload();
+  }
+
+  /**
+   * If upload/removal fails, stop loading.
+   *
+   * @param {Object} response
+   * @protected
+   */
+  failure(response) {
+    this.loading = false;
+    m.redraw();
+  }
+}

js/src/admin/components/Widget.js

@@ -0,0 +1,38 @@
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+import Component from '../../common/Component';
+
+export default class DashboardWidget extends Component {
+  view() {
+    return (
+      <div className={"DashboardWidget "+this.className()}>
+        {this.content()}
+      </div>
+    );
+  }
+
+  /**
+   * Get the class name to apply to the widget.
+   *
+   * @return {String}
+   */
+  className() {
+    return '';
+  }
+
+  /**
+   * Get the content of the widget.
+   *
+   * @return {VirtualElement}
+   */
+  content() {
+    return [];
+  }
+}

js/src/admin/index.js

@@ -0,0 +1,28 @@
+import 'expose-loader?$!expose-loader?jQuery!jquery';
+import 'expose-loader?m!mithril';
+import 'expose-loader?moment!moment';
+import 'expose-loader?m.bidi!m.attrs.bidi';
+import 'bootstrap/js/affix';
+import 'bootstrap/js/dropdown';
+import 'bootstrap/js/modal';
+import 'bootstrap/js/tooltip';
+import 'bootstrap/js/transition';
+
+import AdminApplication from './AdminApplication';
+
+const app = new AdminApplication();
+
+// Backwards compatibility
+window.app = app;
+
+export { app };
+
+// Export public API
+
+
+// Export compat API
+import compat from './compat';
+
+compat.app = app;
+
+export { compat };

js/src/admin/routes.js

@@ -0,0 +1,22 @@
+import DashboardPage from './components/DashboardPage';
+import BasicsPage from './components/BasicsPage';
+import PermissionsPage from './components/PermissionsPage';
+import AppearancePage from './components/AppearancePage';
+import ExtensionsPage from './components/ExtensionsPage';
+import MailPage from './components/MailPage';
+
+/**
+ * The `routes` initializer defines the forum app's routes.
+ *
+ * @param {App} app
+ */
+export default function(app) {
+  app.routes = {
+    'dashboard': {path: '/', component: DashboardPage.component()},
+    'basics': {path: '/basics', component: BasicsPage.component()},
+    'permissions': {path: '/permissions', component: PermissionsPage.component()},
+    'appearance': {path: '/appearance', component: AppearancePage.component()},
+    'extensions': {path: '/extensions', component: ExtensionsPage.component()},
+    'mail': {path: '/mail', component: MailPage.component()}
+  };
+}

js/src/admin/utils/saveSettings.js

@@ -0,0 +1,14 @@
+export default function saveSettings(settings) {
+  const oldSettings = JSON.parse(JSON.stringify(app.data.settings));
+
+  Object.assign(app.data.settings, settings);
+
+  return app.request({
+    method: 'POST',
+    url: app.forum.attribute('apiUrl') + '/settings',
+    data: settings
+  }).catch(error => {
+    app.data.settings = oldSettings;
+    throw error;
+  });
+}

js/src/common/Application.js

@@ -0,0 +1,366 @@
+import ItemList from './utils/ItemList';
+import Alert from './components/Alert';
+import Button from './components/Button';
+import ModalManager from './components/ModalManager';
+import AlertManager from './components/AlertManager';
+import RequestErrorModal from './components/RequestErrorModal';
+import Translator from './Translator';
+import Store from './Store';
+import Session from './Session';
+import extract from './utils/extract';
+import Drawer from './utils/Drawer';
+import mapRoutes from './utils/mapRoutes';
+import patchMithril from './utils/patchMithril';
+import RequestError from './utils/RequestError';
+import ScrollListener from './utils/ScrollListener';
+import { extend } from './extend';
+
+import Forum from './models/Forum';
+import User from './models/User';
+import Discussion from './models/Discussion';
+import Post from './models/Post';
+import Group from './models/Group';
+import Notification from './models/Notification';
+
+/**
+ * The `App` class provides a container for an application, as well as various
+ * utilities for the rest of the app to use.
+ */
+export default class Application {
+  /**
+   * The forum model for this application.
+   *
+   * @type {Forum}
+   * @public
+   */
+  forum = null;
+
+  /**
+   * A map of routes, keyed by a unique route name. Each route is an object
+   * containing the following properties:
+   *
+   * - `path` The path that the route is accessed at.
+   * - `component` The Mithril component to render when this route is active.
+   *
+   * @example
+   * app.routes.discussion = {path: '/d/:id', component: DiscussionPage.component()};
+   *
+   * @type {Object}
+   * @public
+   */
+  routes = {};
+
+  /**
+   * An ordered list of initializers to bootstrap the application.
+   *
+   * @type {ItemList}
+   * @public
+   */
+  initializers = new ItemList();
+
+  /**
+   * The app's session.
+   *
+   * @type {Session}
+   * @public
+   */
+  session = null;
+
+  /**
+   * The app's translator.
+   *
+   * @type {Translator}
+   * @public
+   */
+  translator = new Translator();
+
+  /**
+   * The app's data store.
+   *
+   * @type {Store}
+   * @public
+   */
+  store = new Store({
+    forums: Forum,
+    users: User,
+    discussions: Discussion,
+    posts: Post,
+    groups: Group,
+    notifications: Notification
+  });
+
+  /**
+   * A local cache that can be used to store data at the application level, so
+   * that is persists between different routes.
+   *
+   * @type {Object}
+   * @public
+   */
+  cache = {};
+
+  /**
+   * Whether or not the app has been booted.
+   *
+   * @type {Boolean}
+   * @public
+   */
+  booted = false;
+
+  /**
+   * An Alert that was shown as a result of an AJAX request error. If present,
+   * it will be dismissed on the next successful request.
+   *
+   * @type {null|Alert}
+   * @private
+   */
+  requestError = null;
+
+  title = '';
+  titleCount = 0;
+
+  boot(data) {
+    this.data = data;
+
+    this.translator.locale = data.locale;
+
+    patchMithril(window);
+
+    this.initializers.toArray().forEach(initializer => initializer(this));
+
+    this.store.pushPayload({data: this.data.resources});
+
+    this.forum = this.store.getById('forums', 1);
+
+    this.session = new Session(
+        this.store.getById('users', this.data.session.userId),
+        this.data.session.csrfToken
+    );
+
+    this.mount();
+  }
+
+  mount() {
+    this.modal = m.mount(document.getElementById('modal'), <ModalManager/>);
+    this.alerts = m.mount(document.getElementById('alerts'), <AlertManager/>);
+
+    this.drawer = new Drawer();
+
+    const basePath = this.forum.attribute('basePath');
+    m.route(
+      document.getElementById('content'),
+      basePath + '/',
+      mapRoutes(this.routes, basePath)
+    );
+
+    // Add a class to the body which indicates that the page has been scrolled
+    // down.
+    new ScrollListener(top => {
+      const $app = $('#app');
+      const offset = $app.offset().top;
+
+      $app
+        .toggleClass('affix', top >= offset)
+        .toggleClass('scrolled', top > offset);
+    }).start();
+
+    $(() => {
+      $('body').addClass('ontouchstart' in window ? 'touch' : 'no-touch');
+    });
+  }
+
+  /**
+   * Get the API response document that has been preloaded into the application.
+   *
+   * @return {Object|null}
+   * @public
+   */
+  preloadedDocument() {
+    if (this.data.document) {
+      const results = this.store.pushPayload(this.data.document);
+
+      this.data.document = null;
+
+      return results;
+    }
+
+    return null;
+  }
+
+  /**
+   * Set the <title> of the page.
+   *
+   * @param {String} title
+   * @public
+   */
+  setTitle(title) {
+    this.title = title;
+    this.updateTitle();
+  }
+
+  /**
+   * Set a number to display in the <title> of the page.
+   *
+   * @param {Integer} count
+   */
+  setTitleCount(count) {
+    this.titleCount = count;
+    this.updateTitle();
+  }
+
+  updateTitle() {
+    document.title = (this.titleCount ? `(${this.titleCount}) ` : '') +
+      (this.title ? this.title + ' - ' : '') +
+      this.forum.attribute('title');
+  }
+
+  /**
+   * Make an AJAX request, handling any low-level errors that may occur.
+   *
+   * @see https://lhorie.github.io/mithril/mithril.request.html
+   * @param {Object} options
+   * @return {Promise}
+   * @public
+   */
+  request(originalOptions) {
+    const options = Object.assign({}, originalOptions);
+
+    // Set some default options if they haven't been overridden. We want to
+    // authenticate all requests with the session token. We also want all
+    // requests to run asynchronously in the background, so that they don't
+    // prevent redraws from occurring.
+    options.background = options.background || true;
+
+    extend(options, 'config', (result, xhr) => xhr.setRequestHeader('X-CSRF-Token', this.session.csrfToken));
+
+    // If the method is something like PATCH or DELETE, which not all servers
+    // and clients support, then we'll send it as a POST request with the
+    // intended method specified in the X-HTTP-Method-Override header.
+    if (options.method !== 'GET' && options.method !== 'POST') {
+      const method = options.method;
+      extend(options, 'config', (result, xhr) => xhr.setRequestHeader('X-HTTP-Method-Override', method));
+      options.method = 'POST';
+    }
+
+    // When we deserialize JSON data, if for some reason the server has provided
+    // a dud response, we don't want the application to crash. We'll show an
+    // error message to the user instead.
+    options.deserialize = options.deserialize || (responseText => responseText);
+
+    options.errorHandler = options.errorHandler || (error => {
+      throw error;
+    });
+
+    // When extracting the data from the response, we can check the server
+    // response code and show an error message to the user if something's gone
+    // awry.
+    const original = options.extract;
+    options.extract = xhr => {
+      let responseText;
+
+      if (original) {
+        responseText = original(xhr.responseText);
+      } else {
+        responseText = xhr.responseText || null;
+      }
+
+      const status = xhr.status;
+
+      if (status < 200 || status > 299) {
+        throw new RequestError(status, responseText, options, xhr);
+      }
+
+      if (xhr.getResponseHeader) {
+        const csrfToken = xhr.getResponseHeader('X-CSRF-Token');
+        if (csrfToken) app.session.csrfToken = csrfToken;
+      }
+
+      try {
+        return JSON.parse(responseText);
+      } catch (e) {
+        throw new RequestError(500, responseText, options, xhr);
+      }
+    };
+
+    if (this.requestError) this.alerts.dismiss(this.requestError.alert);
+
+    // Now make the request. If it's a failure, inspect the error that was
+    // returned and show an alert containing its contents.
+    const deferred = m.deferred();
+
+    m.request(options).then(response => deferred.resolve(response), error => {
+      this.requestError = error;
+
+      let children;
+
+      switch (error.status) {
+        case 422:
+          children = error.response.errors
+            .map(error => [error.detail, <br/>])
+            .reduce((a, b) => a.concat(b), [])
+            .slice(0, -1);
+          break;
+
+        case 401:
+        case 403:
+          children = app.translator.trans('core.lib.error.permission_denied_message');
+          break;
+
+        case 404:
+        case 410:
+          children = app.translator.trans('core.lib.error.not_found_message');
+          break;
+
+        case 429:
+          children = app.translator.trans('core.lib.error.rate_limit_exceeded_message');
+          break;
+
+        default:
+          children = app.translator.trans('core.lib.error.generic_message');
+      }
+
+      error.alert = new Alert({
+        type: 'error',
+        children,
+        controls: app.forum.attribute('debug') ? [
+          <Button className="Button Button--link" onclick={this.showDebug.bind(this, error)}>Debug</Button>
+        ] : undefined
+      });
+
+      try {
+        options.errorHandler(error);
+      } catch (error) {
+        this.alerts.show(error.alert);
+      }
+
+      deferred.reject(error);
+    });
+
+    return deferred.promise;
+  }
+
+  /**
+   * @param {RequestError} error
+   * @private
+   */
+  showDebug(error) {
+    this.alerts.dismiss(this.requestErrorAlert);
+
+    this.modal.show(new RequestErrorModal({error}));
+  }
+
+  /**
+   * Construct a URL to the route with the given name.
+   *
+   * @param {String} name
+   * @param {Object} params
+   * @return {String}
+   * @public
+   */
+  route(name, params = {}) {
+    const url = this.routes[name].path.replace(/:([^\/]+)/g, (m, key) => extract(params, key));
+    const queryString = m.route.buildQueryString(params);
+    const prefix = m.route.mode === 'pathname' ? app.forum.attribute('basePath') : '';
+
+    return prefix + url + (queryString ? '?' + queryString : '');
+  }
+}

js/src/common/Component.js

@@ -0,0 +1,225 @@
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * The `Component` class defines a user interface 'building block'. A component
+ * can generate a virtual DOM to be rendered on each redraw.
+ *
+ * An instance's virtual DOM can be retrieved directly using the {@link
+ * Component#render} method.
+ *
+ * @example
+ * this.myComponentInstance = new MyComponent({foo: 'bar'});
+ * return m('div', this.myComponentInstance.render());
+ *
+ * Alternatively, components can be nested, letting Mithril take care of
+ * instance persistence. For this, the static {@link Component.component} method
+ * can be used.
+ *
+ * @example
+ * return m('div', MyComponent.component({foo: 'bar'));
+ *
+ * @see https://lhorie.github.io/mithril/mithril.component.html
+ * @abstract
+ */
+export default class Component {
+  /**
+   * @param {Object} props
+   * @param {Array|Object} children
+   * @public
+   */
+  constructor(props = {}, children = null) {
+    if (children) props.children = children;
+
+    this.constructor.initProps(props);
+
+    /**
+     * The properties passed into the component.
+     *
+     * @type {Object}
+     */
+    this.props = props;
+
+    /**
+     * The root DOM element for the component.
+     *
+     * @type DOMElement
+     * @public
+     */
+    this.element = null;
+
+    /**
+     * Whether or not to retain the component's subtree on redraw.
+     *
+     * @type {boolean}
+     * @public
+     */
+    this.retain = false;
+
+    this.init();
+  }
+
+  /**
+   * Called when the component is constructed.
+   *
+   * @protected
+   */
+  init() {
+  }
+
+  /**
+   * Called when the component is destroyed, i.e. after a redraw where it is no
+   * longer a part of the view.
+   *
+   * @see https://lhorie.github.io/mithril/mithril.component.html#unloading-components
+   * @param {Object} e
+   * @public
+   */
+  onunload() {
+  }
+
+  /**
+   * Get the renderable virtual DOM that represents the component's view.
+   *
+   * This should NOT be overridden by subclasses. Subclasses wishing to define
+   * their virtual DOM should override Component#view instead.
+   *
+   * @example
+   * this.myComponentInstance = new MyComponent({foo: 'bar'});
+   * return m('div', this.myComponentInstance.render());
+   *
+   * @returns {Object}
+   * @final
+   * @public
+   */
+  render() {
+    const vdom = this.retain ? {subtree: 'retain'} : this.view();
+
+    // Override the root element's config attribute with our own function, which
+    // will set the component instance's element property to the root DOM
+    // element, and then run the component class' config method.
+    vdom.attrs = vdom.attrs || {};
+
+    const originalConfig = vdom.attrs.config;
+
+    vdom.attrs.config = (...args) => {
+      this.element = args[0];
+      this.config.apply(this, args.slice(1));
+      if (originalConfig) originalConfig.apply(this, args);
+    };
+
+    return vdom;
+  }
+
+  /**
+   * Returns a jQuery object for this component's element. If you pass in a
+   * selector string, this method will return a jQuery object, using the current
+   * element as its buffer.
+   *
+   * For example, calling `component.$('li')` will return a jQuery object
+   * containing all of the `li` elements inside the DOM element of this
+   * component.
+   *
+   * @param {String} [selector] a jQuery-compatible selector string
+   * @returns {jQuery} the jQuery object for the DOM node
+   * @final
+   * @public
+   */
+  $(selector) {
+    const $element = $(this.element);
+
+    return selector ? $element.find(selector) : $element;
+  }
+
+  /**
+   * Called after the component's root element is redrawn. This hook can be used
+   * to perform any actions on the DOM, both on the initial draw and any
+   * subsequent redraws. See Mithril's documentation for more information.
+   *
+   * @see https://lhorie.github.io/mithril/mithril.html#the-config-attribute
+   * @param {Boolean} isInitialized
+   * @param {Object} context
+   * @param {Object} vdom
+   * @public
+   */
+  config() {
+  }
+
+  /**
+   * Get the virtual DOM that represents the component's view.
+   *
+   * @return {Object} The virtual DOM
+   * @protected
+   */
+  view() {
+    throw new Error('Component#view must be implemented by subclass');
+  }
+
+  /**
+   * Get a Mithril component object for this component, preloaded with props.
+   *
+   * @see https://lhorie.github.io/mithril/mithril.component.html
+   * @param {Object} [props] Properties to set on the component
+   * @param children
+   * @return {Object} The Mithril component object
+   * @property {function} controller
+   * @property {function} view
+   * @property {Object} component The class of this component
+   * @property {Object} props The props that were passed to the component
+   * @public
+   */
+  static component(props = {}, children = null) {
+    const componentProps = Object.assign({}, props);
+
+    if (children) componentProps.children = children;
+
+    this.initProps(componentProps);
+
+    // Set up a function for Mithril to get the component's view. It will accept
+    // the component's controller (which happens to be the component itself, in
+    // our case), update its props with the ones supplied, and then render the view.
+    const view = (component) => {
+      component.props = componentProps;
+      return component.render();
+    };
+
+    // Mithril uses this property on the view function to cache component
+    // controllers between redraws, thus persisting component state.
+    view.$original = this.prototype.view;
+
+    // Our output object consists of a controller constructor + a view function
+    // which Mithril will use to instantiate and render the component. We also
+    // attach a reference to the props that were passed through and the
+    // component's class for reference.
+    const output = {
+      controller: this.bind(undefined, componentProps),
+      view: view,
+      props: componentProps,
+      component: this
+    };
+
+    // If a `key` prop was set, then we'll assume that we want that to actually
+    // show up as an attribute on the component object so that Mithril's key
+    // algorithm can be applied.
+    if (componentProps.key) {
+      output.attrs = {key: componentProps.key};
+    }
+
+    return output;
+  }
+
+  /**
+   * Initialize the component's props.
+   *
+   * @param {Object} props
+   * @public
+   */
+  static initProps(props) {
+  }
+}

js/src/common/Model.js

@@ -0,0 +1,307 @@
+/**
+ * The `Model` class represents a local data resource. It provides methods to
+ * persist changes via the API.
+ *
+ * @abstract
+ */
+export default class Model {
+  /**
+   * @param {Object} data A resource object from the API.
+   * @param {Store} store The data store that this model should be persisted to.
+   * @public
+   */
+  constructor(data = {}, store = null) {
+    /**
+     * The resource object from the API.
+     *
+     * @type {Object}
+     * @public
+     */
+    this.data = data;
+
+    /**
+     * The time at which the model's data was last updated. Watching the value
+     * of this property is a fast way to retain/cache a subtree if data hasn't
+     * changed.
+     *
+     * @type {Date}
+     * @public
+     */
+    this.freshness = new Date();
+
+    /**
+     * Whether or not the resource exists on the server.
+     *
+     * @type {Boolean}
+     * @public
+     */
+    this.exists = false;
+
+    /**
+     * The data store that this resource should be persisted to.
+     *
+     * @type {Store}
+     * @protected
+     */
+    this.store = store;
+  }
+
+  /**
+   * Get the model's ID.
+   *
+   * @return {Integer}
+   * @public
+   * @final
+   */
+  id() {
+    return this.data.id;
+  }
+
+  /**
+   * Get one of the model's attributes.
+   *
+   * @param {String} attribute
+   * @return {*}
+   * @public
+   * @final
+   */
+  attribute(attribute) {
+    return this.data.attributes[attribute];
+  }
+
+  /**
+   * Merge new data into this model locally.
+   *
+   * @param {Object} data A resource object to merge into this model
+   * @public
+   */
+  pushData(data) {
+    // Since most of the top-level items in a resource object are objects
+    // (e.g. relationships, attributes), we'll need to check and perform the
+    // merge at the second level if that's the case.
+    for (const key in data) {
+      if (typeof data[key] === 'object') {
+        this.data[key] = this.data[key] || {};
+
+        // For every item in a second-level object, we want to check if we've
+        // been handed a Model instance. If so, we will convert it to a
+        // relationship data object.
+        for (const innerKey in data[key]) {
+          if (data[key][innerKey] instanceof Model) {
+            data[key][innerKey] = {data: Model.getIdentifier(data[key][innerKey])};
+          }
+          this.data[key][innerKey] = data[key][innerKey];
+        }
+      } else {
+        this.data[key] = data[key];
+      }
+    }
+
+    // Now that we've updated the data, we can say that the model is fresh.
+    // This is an easy way to invalidate retained subtrees etc.
+    this.freshness = new Date();
+  }
+
+  /**
+   * Merge new attributes into this model locally.
+   *
+   * @param {Object} attributes The attributes to merge.
+   * @public
+   */
+  pushAttributes(attributes) {
+    this.pushData({attributes});
+  }
+
+  /**
+   * Merge new attributes into this model, both locally and with persistence.
+   *
+   * @param {Object} attributes The attributes to save. If a 'relationships' key
+   *     exists, it will be extracted and relationships will also be saved.
+   * @param {Object} [options]
+   * @return {Promise}
+   * @public
+   */
+  save(attributes, options = {}) {
+    const data = {
+      type: this.data.type,
+      id: this.data.id,
+      attributes
+    };
+
+    // If a 'relationships' key exists, extract it from the attributes hash and
+    // set it on the top-level data object instead. We will be sending this data
+    // object to the API for persistence.
+    if (attributes.relationships) {
+      data.relationships = {};
+
+      for (const key in attributes.relationships) {
+        const model = attributes.relationships[key];
+
+        data.relationships[key] = {
+          data: model instanceof Array
+            ? model.map(Model.getIdentifier)
+            : Model.getIdentifier(model)
+        };
+      }
+
+      delete attributes.relationships;
+    }
+
+    // Before we update the model's data, we should make a copy of the model's
+    // old data so that we can revert back to it if something goes awry during
+    // persistence.
+    const oldData = this.copyData();
+
+    this.pushData(data);
+
+    const request = {data};
+    if (options.meta) request.meta = options.meta;
+
+    return app.request(Object.assign({
+      method: this.exists ? 'PATCH' : 'POST',
+      url: app.forum.attribute('apiUrl') + this.apiEndpoint(),
+      data: request
+    }, options)).then(
+      // If everything went well, we'll make sure the store knows that this
+      // model exists now (if it didn't already), and we'll push the data that
+      // the API returned into the store.
+      payload => {
+        this.store.data[payload.data.type] = this.store.data[payload.data.type] || {};
+        this.store.data[payload.data.type][payload.data.id] = this;
+        return this.store.pushPayload(payload);
+      },
+
+      // If something went wrong, though... good thing we backed up our model's
+      // old data! We'll revert to that and let others handle the error.
+      response => {
+        this.pushData(oldData);
+        m.lazyRedraw();
+        throw response;
+      }
+    );
+  }
+
+  /**
+   * Send a request to delete the resource.
+   *
+   * @param {Object} data Data to send along with the DELETE request.
+   * @param {Object} [options]
+   * @return {Promise}
+   * @public
+   */
+  delete(data, options = {}) {
+    if (!this.exists) return m.deferred.resolve().promise;
+
+    return app.request(Object.assign({
+      method: 'DELETE',
+      url: app.forum.attribute('apiUrl') + this.apiEndpoint(),
+      data
+    }, options)).then(() => {
+      this.exists = false;
+      this.store.remove(this);
+    });
+  }
+
+  /**
+   * Construct a path to the API endpoint for this resource.
+   *
+   * @return {String}
+   * @protected
+   */
+  apiEndpoint() {
+    return '/' + this.data.type + (this.exists ? '/' + this.data.id : '');
+  }
+
+  copyData() {
+    return JSON.parse(JSON.stringify(this.data));
+  }
+
+  /**
+   * Generate a function which returns the value of the given attribute.
+   *
+   * @param {String} name
+   * @param {function} [transform] A function to transform the attribute value
+   * @return {*}
+   * @public
+   */
+  static attribute(name, transform) {
+    return function() {
+      const value = this.data.attributes && this.data.attributes[name];
+
+      return transform ? transform(value) : value;
+    };
+  }
+
+  /**
+   * Generate a function which returns the value of the given has-one
+   * relationship.
+   *
+   * @param {String} name
+   * @return {Model|Boolean|undefined} false if no information about the
+   *     relationship exists; undefined if the relationship exists but the model
+   *     has not been loaded; or the model if it has been loaded.
+   * @public
+   */
+  static hasOne(name) {
+    return function() {
+      if (this.data.relationships) {
+        const relationship = this.data.relationships[name];
+
+        if (relationship) {
+          return app.store.getById(relationship.data.type, relationship.data.id);
+        }
+      }
+
+      return false;
+    };
+  }
+
+  /**
+   * Generate a function which returns the value of the given has-many
+   * relationship.
+   *
+   * @param {String} name
+   * @return {Array|Boolean} false if no information about the relationship
+   *     exists; an array if it does, containing models if they have been
+   *     loaded, and undefined for those that have not.
+   * @public
+   */
+  static hasMany(name) {
+    return function() {
+      if (this.data.relationships) {
+        const relationship = this.data.relationships[name];
+
+        if (relationship) {
+          return relationship.data.map(data => app.store.getById(data.type, data.id));
+        }
+      }
+
+      return false;
+    };
+  }
+
+  /**
+   * Transform the given value into a Date object.
+   *
+   * @param {String} value
+   * @return {Date|null}
+   * @public
+   */
+  static transformDate(value) {
+    return value ? new Date(value) : null;
+  }
+
+  /**
+   * Get a resource identifier object for the given model.
+   *
+   * @param {Model} model
+   * @return {Object}
+   * @protected
+   */
+  static getIdentifier(model) {
+    return {
+      type: model.data.type,
+      id: model.data.id
+    };
+  }
+}

js/src/common/Session.js

@@ -0,0 +1,49 @@
+/**
+ * The `Session` class defines the current user session. It stores a reference
+ * to the current authenticated user, and provides methods to log in/out.
+ */
+export default class Session {
+  constructor(user, csrfToken) {
+    /**
+     * The current authenticated user.
+     *
+     * @type {User|null}
+     * @public
+     */
+    this.user = user;
+
+    /**
+     * The CSRF token.
+     *
+     * @type {String|null}
+     * @public
+     */
+    this.csrfToken = csrfToken;
+  }
+
+  /**
+   * Attempt to log in a user.
+   *
+   * @param {String} identification The username/email.
+   * @param {String} password
+   * @param {Object} [options]
+   * @return {Promise}
+   * @public
+   */
+  login(data, options = {}) {
+    return app.request(Object.assign({
+      method: 'POST',
+      url: app.forum.attribute('baseUrl') + '/login',
+      data
+    }, options));
+  }
+
+  /**
+   * Log the user out.
+   *
+   * @public
+   */
+  logout() {
+    window.location = app.forum.attribute('baseUrl') + '/logout?token=' + this.csrfToken;
+  }
+}

js/src/common/Store.js

@@ -0,0 +1,165 @@
+/**
+ * The `Store` class defines a local data store, and provides methods to
+ * retrieve data from the API.
+ */
+export default class Store {
+  constructor(models) {
+    /**
+     * The local data store. A tree of resource types to IDs, such that
+     * accessing data[type][id] will return the model for that type/ID.
+     *
+     * @type {Object}
+     * @protected
+     */
+    this.data = {};
+
+    /**
+     * The model registry. A map of resource types to the model class that
+     * should be used to represent resources of that type.
+     *
+     * @type {Object}
+     * @public
+     */
+    this.models = models;
+  }
+
+  /**
+   * Push resources contained within an API payload into the store.
+   *
+   * @param {Object} payload
+   * @return {Model|Model[]} The model(s) representing the resource(s) contained
+   *     within the 'data' key of the payload.
+   * @public
+   */
+  pushPayload(payload) {
+    if (payload.included) payload.included.map(this.pushObject.bind(this));
+
+    const result = payload.data instanceof Array
+      ? payload.data.map(this.pushObject.bind(this))
+      : this.pushObject(payload.data);
+
+    // Attach the original payload to the model that we give back. This is
+    // useful to consumers as it allows them to access meta information
+    // associated with their request.
+    result.payload = payload;
+
+    return result;
+  }
+
+  /**
+   * Create a model to represent a resource object (or update an existing one),
+   * and push it into the store.
+   *
+   * @param {Object} data The resource object
+   * @return {Model|null} The model, or null if no model class has been
+   *     registered for this resource type.
+   * @public
+   */
+  pushObject(data) {
+    if (!this.models[data.type]) return null;
+
+    const type = this.data[data.type] = this.data[data.type] || {};
+
+    if (type[data.id]) {
+      type[data.id].pushData(data);
+    } else {
+      type[data.id] = this.createRecord(data.type, data);
+    }
+
+    type[data.id].exists = true;
+
+    return type[data.id];
+  }
+
+  /**
+   * Make a request to the API to find record(s) of a specific type.
+   *
+   * @param {String} type The resource type.
+   * @param {Integer|Integer[]|Object} [id] The ID(s) of the model(s) to retreive.
+   *     Alternatively, if an object is passed, it will be handled as the
+   *     `query` parameter.
+   * @param {Object} [query]
+   * @param {Object} [options]
+   * @return {Promise}
+   * @public
+   */
+  find(type, id, query = {}, options = {}) {
+    let data = query;
+    let url = app.forum.attribute('apiUrl') + '/' + type;
+
+    if (id instanceof Array) {
+      url += '?filter[id]=' + id.join(',');
+    } else if (typeof id === 'object') {
+      data = id;
+    } else if (id) {
+      url += '/' + id;
+    }
+
+    return app.request(Object.assign({
+      method: 'GET',
+      url,
+      data
+    }, options)).then(this.pushPayload.bind(this));
+  }
+
+  /**
+   * Get a record from the store by ID.
+   *
+   * @param {String} type The resource type.
+   * @param {Integer} id The resource ID.
+   * @return {Model}
+   * @public
+   */
+  getById(type, id) {
+    return this.data[type] && this.data[type][id];
+  }
+
+  /**
+   * Get a record from the store by the value of a model attribute.
+   *
+   * @param {String} type The resource type.
+   * @param {String} key The name of the method on the model.
+   * @param {*} value The value of the model attribute.
+   * @return {Model}
+   * @public
+   */
+  getBy(type, key, value) {
+    return this.all(type).filter(model => model[key]() === value)[0];
+  }
+
+  /**
+   * Get all loaded records of a specific type.
+   *
+   * @param {String} type
+   * @return {Model[]}
+   * @public
+   */
+  all(type) {
+    const records = this.data[type];
+
+    return records ? Object.keys(records).map(id => records[id]) : [];
+  }
+
+  /**
+   * Remove the given model from the store.
+   *
+   * @param {Model} model
+   */
+  remove(model) {
+    delete this.data[model.data.type][model.id()];
+  }
+
+  /**
+   * Create a new record of the given type.
+   *
+   * @param {String} type The resource type
+   * @param {Object} [data] Any data to initialize the model with
+   * @return {Model}
+   * @public
+   */
+  createRecord(type, data = {}) {
+    data.type = data.type || type;
+
+    return new (this.models[type])(data, this);
+  }
+}

js/src/common/Translator.js

@@ -0,0 +1,285 @@
+import User from './models/User';
+import username from './helpers/username';
+import extractText from './utils/extractText';
+import extract from './utils/extract';
+
+/**
+ * Translator with the same API as Symfony's.
+ *
+ * Derived from https://github.com/willdurand/BazingaJsTranslationBundle
+ * which is available under the MIT License.
+ * Copyright (c) William Durand <william.durand1@gmail.com>
+ */
+export default class Translator {
+  constructor() {
+    /**
+     * A map of translation keys to their translated values.
+     *
+     * @type {Object}
+     * @public
+     */
+    this.translations = {};
+
+    this.locale = null;
+  }
+
+  trans(id, parameters) {
+    const translation = this.translations[id];
+
+    if (translation) {
+      return this.apply(translation, parameters || {});
+    }
+
+    return id;
+  }
+
+  transChoice(id, number, parameters) {
+    let translation = this.translations[id];
+
+    if (translation) {
+      number = parseInt(number, 10);
+
+      translation = this.pluralize(translation, number);
+
+      return this.apply(translation, parameters || {});
+    }
+
+    return id;
+  }
+
+  apply(translation, input) {
+    // If we've been given a user model as one of the input parameters, then
+    // we'll extract the username and use that for the translation. In the
+    // future there should be a hook here to inspect the user and change the
+    // translation key. This will allow a gender property to determine which
+    // translation key is used.
+    if ('user' in input) {
+      const user = extract(input, 'user');
+
+      if (!input.username) input.username = username(user);
+    }
+
+    translation = translation.split(new RegExp('({[a-z0-9_]+}|</?[a-z0-9_]+>)', 'gi'));
+
+    const hydrated = [];
+    const open = [hydrated];
+
+    translation.forEach(part => {
+      const match = part.match(new RegExp('{([a-z0-9_]+)}|<(/?)([a-z0-9_]+)>', 'i'));
+
+      if (match) {
+        if (match[1]) {
+          open[0].push(input[match[1]]);
+        } else if (match[3]) {
+          if (match[2]) {
+            open.shift();
+          } else {
+            let tag = input[match[3]] || {tag: match[3], children: []};
+            open[0].push(tag);
+            open.unshift(tag.children || tag);
+          }
+        }
+      } else {
+        open[0].push(part);
+      }
+    });
+
+    return hydrated.filter(part => part);
+  }
+
+  pluralize(translation, number) {
+    const sPluralRegex = new RegExp(/^\w+\: +(.+)$/),
+      cPluralRegex = new RegExp(/^\s*((\{\s*(\-?\d+[\s*,\s*\-?\d+]*)\s*\})|([\[\]])\s*(-Inf|\-?\d+)\s*,\s*(\+?Inf|\-?\d+)\s*([\[\]]))\s?(.+?)$/),
+      iPluralRegex = new RegExp(/^\s*(\{\s*(\-?\d+[\s*,\s*\-?\d+]*)\s*\})|([\[\]])\s*(-Inf|\-?\d+)\s*,\s*(\+?Inf|\-?\d+)\s*([\[\]])/),
+      standardRules = [],
+      explicitRules = [];
+
+    translation.split('|').forEach(part => {
+      if (cPluralRegex.test(part)) {
+        const matches = part.match(cPluralRegex);
+        explicitRules[matches[0]] = matches[matches.length - 1];
+      } else if (sPluralRegex.test(part)) {
+        const matches = part.match(sPluralRegex);
+        standardRules.push(matches[1]);
+      } else {
+        standardRules.push(part);
+      }
+    });
+
+    explicitRules.forEach((rule, e) => {
+      if (iPluralRegex.test(e)) {
+        const matches = e.match(iPluralRegex);
+
+        if (matches[1]) {
+          const ns = matches[2].split(',');
+
+          for (let n in ns) {
+            if (number == ns[n]) {
+              return explicitRules[e];
+            }
+          }
+        } else {
+          var leftNumber  = this.convertNumber(matches[4]);
+          var rightNumber = this.convertNumber(matches[5]);
+
+          if (('[' === matches[3] ? number >= leftNumber : number > leftNumber) &&
+            (']' === matches[6] ? number <= rightNumber : number < rightNumber)) {
+            return explicitRules[e];
+          }
+        }
+      }
+    });
+
+    return standardRules[this.pluralPosition(number, this.locale)] || standardRules[0] || undefined;
+  }
+
+  convertNumber(number) {
+    if ('-Inf' === number) {
+      return Number.NEGATIVE_INFINITY;
+    } else if ('+Inf' === number || 'Inf' === number) {
+      return Number.POSITIVE_INFINITY;
+    }
+
+    return parseInt(number, 10);
+  }
+
+  pluralPosition(number, locale) {
+    if ('pt_BR' === locale) {
+      locale = 'xbr';
+    }
+
+    if (locale.length > 3) {
+      locale = locale.split('_')[0];
+    }
+
+    switch (locale) {
+      case 'bo':
+      case 'dz':
+      case 'id':
+      case 'ja':
+      case 'jv':
+      case 'ka':
+      case 'km':
+      case 'kn':
+      case 'ko':
+      case 'ms':
+      case 'th':
+      case 'vi':
+      case 'zh':
+        return 0;
+
+      case 'af':
+      case 'az':
+      case 'bn':
+      case 'bg':
+      case 'ca':
+      case 'da':
+      case 'de':
+      case 'el':
+      case 'en':
+      case 'eo':
+      case 'es':
+      case 'et':
+      case 'eu':
+      case 'fa':
+      case 'fi':
+      case 'fo':
+      case 'fur':
+      case 'fy':
+      case 'gl':
+      case 'gu':
+      case 'ha':
+      case 'he':
+      case 'hu':
+      case 'is':
+      case 'it':
+      case 'ku':
+      case 'lb':
+      case 'ml':
+      case 'mn':
+      case 'mr':
+      case 'nah':
+      case 'nb':
+      case 'ne':
+      case 'nl':
+      case 'nn':
+      case 'no':
+      case 'om':
+      case 'or':
+      case 'pa':
+      case 'pap':
+      case 'ps':
+      case 'pt':
+      case 'so':
+      case 'sq':
+      case 'sv':
+      case 'sw':
+      case 'ta':
+      case 'te':
+      case 'tk':
+      case 'tr':
+      case 'ur':
+      case 'zu':
+        return (number == 1) ? 0 : 1;
+
+      case 'am':
+      case 'bh':
+      case 'fil':
+      case 'fr':
+      case 'gun':
+      case 'hi':
+      case 'ln':
+      case 'mg':
+      case 'nso':
+      case 'xbr':
+      case 'ti':
+      case 'wa':
+        return ((number === 0) || (number == 1)) ? 0 : 1;
+
+      case 'be':
+      case 'bs':
+      case 'hr':
+      case 'ru':
+      case 'sr':
+      case 'uk':
+        return ((number % 10 == 1) && (number % 100 != 11)) ? 0 : (((number % 10 >= 2) && (number % 10 <= 4) && ((number % 100 < 10) || (number % 100 >= 20))) ? 1 : 2);
+
+      case 'cs':
+      case 'sk':
+        return (number == 1) ? 0 : (((number >= 2) && (number <= 4)) ? 1 : 2);
+
+      case 'ga':
+        return (number == 1) ? 0 : ((number == 2) ? 1 : 2);
+
+      case 'lt':
+        return ((number % 10 == 1) && (number % 100 != 11)) ? 0 : (((number % 10 >= 2) && ((number % 100 < 10) || (number % 100 >= 20))) ? 1 : 2);
+
+      case 'sl':
+        return (number % 100 == 1) ? 0 : ((number % 100 == 2) ? 1 : (((number % 100 == 3) || (number % 100 == 4)) ? 2 : 3));
+
+      case 'mk':
+        return (number % 10 == 1) ? 0 : 1;
+
+      case 'mt':
+        return (number == 1) ? 0 : (((number === 0) || ((number % 100 > 1) && (number % 100 < 11))) ? 1 : (((number % 100 > 10) && (number % 100 < 20)) ? 2 : 3));
+
+      case 'lv':
+        return (number === 0) ? 0 : (((number % 10 == 1) && (number % 100 != 11)) ? 1 : 2);
+
+      case 'pl':
+        return (number == 1) ? 0 : (((number % 10 >= 2) && (number % 10 <= 4) && ((number % 100 < 12) || (number % 100 > 14))) ? 1 : 2);
+
+      case 'cy':
+        return (number == 1) ? 0 : ((number == 2) ? 1 : (((number == 8) || (number == 11)) ? 2 : 3));
+
+      case 'ro':
+        return (number == 1) ? 0 : (((number === 0) || ((number % 100 > 0) && (number % 100 < 20))) ? 1 : 2);
+
+      case 'ar':
+        return (number === 0) ? 0 : ((number == 1) ? 1 : ((number == 2) ? 2 : (((number >= 3) && (number <= 10)) ? 3 : (((number >= 11) && (number <= 99)) ? 4 : 5))));
+
+      default:
+        return 0;
+    }
+  }
+}

js/src/common/compat.js

@@ -0,0 +1,127 @@
+import * as extend from './extend';
+import Session from './Session';
+import Store from './Store';
+import evented from './utils/evented';
+import liveHumanTimes from './utils/liveHumanTimes';
+import ItemList from './utils/ItemList';
+import mixin from './utils/mixin';
+import humanTime from './utils/humanTime';
+import computed from './utils/computed';
+import Drawer from './utils/Drawer';
+import anchorScroll from './utils/anchorScroll';
+import RequestError from './utils/RequestError';
+import abbreviateNumber from './utils/abbreviateNumber';
+import * as string from './utils/string';
+import SubtreeRetainer from './utils/SubtreeRetainer';
+import extract from './utils/extract';
+import ScrollListener from './utils/ScrollListener';
+import stringToColor from './utils/stringToColor';
+import patchMithril from './utils/patchMithril';
+import classList from './utils/classList';
+import extractText from './utils/extractText';
+import formatNumber from './utils/formatNumber';
+import mapRoutes from './utils/mapRoutes';
+import Notification from './models/Notification';
+import User from './models/User';
+import Post from './models/Post';
+import Discussion from './models/Discussion';
+import Group from './models/Group';
+import Forum from './models/Forum';
+import Component from './Component';
+import Translator from './Translator';
+import AlertManager from './components/AlertManager';
+import Switch from './components/Switch';
+import Badge from './components/Badge';
+import LoadingIndicator from './components/LoadingIndicator';
+import Placeholder from './components/Placeholder';
+import Separator from './components/Separator';
+import Dropdown from './components/Dropdown';
+import SplitDropdown from './components/SplitDropdown';
+import RequestErrorModal from './components/RequestErrorModal';
+import FieldSet from './components/FieldSet';
+import Select from './components/Select';
+import Navigation from './components/Navigation';
+import Alert from './components/Alert';
+import LinkButton from './components/LinkButton';
+import Checkbox from './components/Checkbox';
+import SelectDropdown from './components/SelectDropdown';
+import ModalManager from './components/ModalManager';
+import Button from './components/Button';
+import Modal from './components/Modal';
+import GroupBadge from './components/GroupBadge';
+import Model from './Model';
+import Application from './Application';
+import fullTime from './helpers/fullTime';
+import avatar from './helpers/avatar';
+import icon from './helpers/icon';
+import humanTimeHelper from './helpers/humanTime';
+import punctuateSeries from './helpers/punctuateSeries';
+import highlight from './helpers/highlight';
+import username from './helpers/username';
+import userOnline from './helpers/userOnline';
+import listItems from './helpers/listItems';
+
+export default {
+  'extend': extend,
+  'Session': Session,
+  'Store': Store,
+  'utils/evented': evented,
+  'utils/liveHumanTimes': liveHumanTimes,
+  'utils/ItemList': ItemList,
+  'utils/mixin': mixin,
+  'utils/humanTime': humanTime,
+  'utils/computed': computed,
+  'utils/Drawer': Drawer,
+  'utils/anchorScroll': anchorScroll,
+  'utils/RequestError': RequestError,
+  'utils/abbreviateNumber': abbreviateNumber,
+  'utils/string': string,
+  'utils/SubtreeRetainer': SubtreeRetainer,
+  'utils/extract': extract,
+  'utils/ScrollListener': ScrollListener,
+  'utils/stringToColor': stringToColor,
+  'utils/patchMithril': patchMithril,
+  'utils/classList': classList,
+  'utils/extractText': extractText,
+  'utils/formatNumber': formatNumber,
+  'utils/mapRoutes': mapRoutes,
+  'models/Notification': Notification,
+  'models/User': User,
+  'models/Post': Post,
+  'models/Discussion': Discussion,
+  'models/Group': Group,
+  'models/Forum': Forum,
+  'Component': Component,
+  'Translator': Translator,
+  'components/AlertManager': AlertManager,
+  'components/Switch': Switch,
+  'components/Badge': Badge,
+  'components/LoadingIndicator': LoadingIndicator,
+  'components/Placeholder': Placeholder,
+  'components/Separator': Separator,
+  'components/Dropdown': Dropdown,
+  'components/SplitDropdown': SplitDropdown,
+  'components/RequestErrorModal': RequestErrorModal,
+  'components/FieldSet': FieldSet,
+  'components/Select': Select,
+  'components/Navigation': Navigation,
+  'components/Alert': Alert,
+  'components/LinkButton': LinkButton,
+  'components/Checkbox': Checkbox,
+  'components/SelectDropdown': SelectDropdown,
+  'components/ModalManager': ModalManager,
+  'components/Button': Button,
+  'components/Modal': Modal,
+  'components/GroupBadge': GroupBadge,
+  'Model': Model,
+  'Application': Application,
+  'helpers/fullTime': fullTime,
+  'helpers/avatar': avatar,
+  'helpers/icon': icon,
+  'helpers/humanTime': humanTimeHelper,
+  'helpers/punctuateSeries': punctuateSeries,
+  'helpers/highlight': highlight,
+  'helpers/username': username,
+  'helpers/userOnline': userOnline,
+  'helpers/listItems': listItems
+};

js/src/common/components/Alert.js

@@ -0,0 +1,57 @@
+import Component from '../Component';
+import Button from './Button';
+import listItems from '../helpers/listItems';
+import extract from '../utils/extract';
+
+/**
+ * The `Alert` component represents an alert box, which contains a message,
+ * some controls, and may be dismissible.
+ *
+ * The alert may have the following special props:
+ *
+ * - `type` The type of alert this is. Will be used to give the alert a class
+ *   name of `Alert--{type}`.
+ * - `controls` An array of controls to show in the alert.
+ * - `dismissible` Whether or not the alert can be dismissed.
+ * - `ondismiss` A callback to run when the alert is dismissed.
+ *
+ * All other props will be assigned as attributes on the alert element.
+ */
+export default class Alert extends Component {
+  view() {
+    const attrs = Object.assign({}, this.props);
+
+    const type = extract(attrs, 'type');
+    attrs.className = 'Alert Alert--' + type + ' ' + (attrs.className || '');
+
+    const children = extract(attrs, 'children');
+    const controls = extract(attrs, 'controls') || [];
+
+    // If the alert is meant to be dismissible (which is the case by default),
+    // then we will create a dismiss button to append as the final control in
+    // the alert.
+    const dismissible = extract(attrs, 'dismissible');
+    const ondismiss = extract(attrs, 'ondismiss');
+    const dismissControl = [];
+
+    if (dismissible || dismissible === undefined) {
+      dismissControl.push(
+        <Button
+          icon="fas fa-times"
+          className="Button Button--link Button--icon Alert-dismiss"
+          onclick={ondismiss}/>
+      );
+    }
+
+    return (
+      <div {...attrs}>
+        <span className="Alert-body">
+          {children}
+        </span>
+        <ul className="Alert-controls">
+          {listItems(controls.concat(dismissControl))}
+        </ul>
+      </div>
+    );
+  }
+}

js/src/common/components/AlertManager.js

@@ -0,0 +1,75 @@
+import Component from '../Component';
+import Alert from './Alert';
+
+/**
+ * The `AlertManager` component provides an area in which `Alert` components can
+ * be shown and dismissed.
+ */
+export default class AlertManager extends Component {
+  init() {
+    /**
+     * An array of Alert components which are currently showing.
+     *
+     * @type {Alert[]}
+     * @protected
+     */
+    this.components = [];
+  }
+
+  view() {
+    return (
+      <div className="AlertManager">
+        {this.components.map(component => <div className="AlertManager-alert">{component}</div>)}
+      </div>
+    );
+  }
+
+  config(isInitialized, context) {
+    // Since this component is 'above' the content of the page (that is, it is a
+    // part of the global UI that persists between routes), we will flag the DOM
+    // to be retained across route changes.
+    context.retain = true;
+  }
+
+  /**
+   * Show an Alert in the alerts area.
+   *
+   * @param {Alert} component
+   * @public
+   */
+  show(component) {
+    if (!(component instanceof Alert)) {
+      throw new Error('The AlertManager component can only show Alert components');
+    }
+
+    component.props.ondismiss = this.dismiss.bind(this, component);
+
+    this.components.push(component);
+    m.redraw();
+  }
+
+  /**
+   * Dismiss an alert.
+   *
+   * @param {Alert} component
+   * @public
+   */
+  dismiss(component) {
+    const index = this.components.indexOf(component);
+
+    if (index !== -1) {
+      this.components.splice(index, 1);
+      m.redraw();
+    }
+  }
+
+  /**
+   * Clear all alerts.
+   *
+   * @public
+   */
+  clear() {
+    this.components = [];
+    m.redraw();
+  }
+}

js/src/common/components/Badge.js

@@ -0,0 +1,39 @@
+import Component from '../Component';
+import icon from '../helpers/icon';
+import extract from '../utils/extract';
+
+/**
+ * The `Badge` component represents a user/discussion badge, indicating some
+ * status (e.g. a discussion is stickied, a user is an admin).
+ *
+ * A badge may have the following special props:
+ *
+ * - `type` The type of badge this is. This will be used to give the badge a
+ *   class name of `Badge--{type}`.
+ * - `icon` The name of an icon to show inside the badge.
+ * - `label`
+ *
+ * All other props will be assigned as attributes on the badge element.
+ */
+export default class Badge extends Component {
+  view() {
+    const attrs = Object.assign({}, this.props);
+    const type = extract(attrs, 'type');
+    const iconName = extract(attrs, 'icon');
+
+    attrs.className = 'Badge ' + (type ? 'Badge--' + type : '') + ' ' + (attrs.className || '');
+    attrs.title = extract(attrs, 'label') || '';
+
+    return (
+      <span {...attrs}>
+        {iconName ? icon(iconName, {className: 'Badge-icon'}) : m.trust('&nbsp;')}
+      </span>
+    );
+  }
+
+  config(isInitialized) {
+    if (isInitialized) return;
+
+    if (this.props.label) this.$().tooltip({container: 'body'});
+  }
+}

js/src/common/components/Button.js

@@ -0,0 +1,64 @@
+import Component from '../Component';
+import icon from '../helpers/icon';
+import extract from '../utils/extract';
+import extractText from '../utils/extractText';
+import LoadingIndicator from './LoadingIndicator';
+
+/**
+ * The `Button` component defines an element which, when clicked, performs an
+ * action. The button may have the following special props:
+ *
+ * - `icon` The name of the icon class. If specified, the button will be given a
+ *   'has-icon' class name.
+ * - `disabled` Whether or not the button is disabled. If truthy, the button
+ *   will be given a 'disabled' class name, and any `onclick` handler will be
+ *   removed.
+ * - `loading` Whether or not the button should be in a disabled loading state.
+ *
+ * All other props will be assigned as attributes on the button element.
+ *
+ * Note that a Button has no default class names. This is because a Button can
+ * be used to represent any generic clickable control, like a menu item.
+ */
+export default class Button extends Component {
+  view() {
+    const attrs = Object.assign({}, this.props);
+
+    delete attrs.children;
+
+    attrs.className = attrs.className || '';
+    attrs.type = attrs.type || 'button';
+
+    // If nothing else is provided, we use the textual button content as tooltip
+    if (!attrs.title && this.props.children) {
+      attrs.title = extractText(this.props.children);
+    }
+
+    const iconName = extract(attrs, 'icon');
+    if (iconName) attrs.className += ' hasIcon';
+
+    const loading = extract(attrs, 'loading');
+    if (attrs.disabled || loading) {
+      attrs.className += ' disabled' + (loading ? ' loading' : '');
+      delete attrs.onclick;
+    }
+
+    return <button {...attrs}>{this.getButtonContent()}</button>;
+  }
+
+  /**
+   * Get the template for the button's content.
+   *
+   * @return {*}
+   * @protected
+   */
+  getButtonContent() {
+    const iconName = this.props.icon;
+
+    return [
+      iconName && iconName !== true ? icon(iconName, {className: 'Button-icon'}) : '',
+      this.props.children ? <span className="Button-label">{this.props.children}</span> : '',
+      this.props.loading ? LoadingIndicator.component({size: 'tiny', className: 'LoadingIndicator--inline'}) : ''
+    ];
+  }
+}

js/src/common/components/Checkbox.js

@@ -0,0 +1,67 @@
+import Component from '../Component';
+import LoadingIndicator from './LoadingIndicator';
+import icon from '../helpers/icon';
+
+/**
+ * The `Checkbox` component defines a checkbox input.
+ *
+ * ### Props
+ *
+ * - `state` Whether or not the checkbox is checked.
+ * - `className` The class name for the root element.
+ * - `disabled` Whether or not the checkbox is disabled.
+ * - `onchange` A callback to run when the checkbox is checked/unchecked.
+ * - `children` A text label to display next to the checkbox.
+ */
+export default class Checkbox extends Component {
+  init() {
+    /**
+     * Whether or not the checkbox's value is in the process of being saved.
+     *
+     * @type {Boolean}
+     * @public
+     */
+    this.loading = false;
+  }
+
+  view() {
+    let className = 'Checkbox ' + (this.props.state ? 'on' : 'off') + ' ' + (this.props.className || '');
+    if (this.loading) className += ' loading';
+    if (this.props.disabled) className += ' disabled';
+
+    return (
+      <label className={className}>
+        <input type="checkbox"
+          checked={this.props.state}
+          disabled={this.props.disabled}
+          onchange={m.withAttr('checked', this.onchange.bind(this))}/>
+        <div className="Checkbox-display">
+          {this.getDisplay()}
+        </div>
+        {this.props.children}
+      </label>
+    );
+  }
+
+  /**
+   * Get the template for the checkbox's display (tick/cross icon).
+   *
+   * @return {*}
+   * @protected
+   */
+  getDisplay() {
+    return this.loading
+      ? LoadingIndicator.component({size: 'tiny'})
+      : icon(this.props.state ? 'fas fa-check' : 'fas fa-times');
+  }
+
+  /**
+   * Run a callback when the state of the checkbox is changed.
+   *
+   * @param {Boolean} checked
+   * @protected
+   */
+  onchange(checked) {
+    if (this.props.onchange) this.props.onchange(checked, this);
+  }
+}

js/src/common/components/Dropdown.js

@@ -0,0 +1,131 @@
+import Component from '../Component';
+import icon from '../helpers/icon';
+import listItems from '../helpers/listItems';
+
+/**
+ * The `Dropdown` component displays a button which, when clicked, shows a
+ * dropdown menu beneath it.
+ *
+ * ### Props
+ *
+ * - `buttonClassName` A class name to apply to the dropdown toggle button.
+ * - `menuClassName` A class name to apply to the dropdown menu.
+ * - `icon` The name of an icon to show in the dropdown toggle button.
+ * - `caretIcon` The name of an icon to show on the right of the button.
+ * - `label` The label of the dropdown toggle button. Defaults to 'Controls'.
+ * - `onhide`
+ * - `onshow`
+ *
+ * The children will be displayed as a list inside of the dropdown menu.
+ */
+export default class Dropdown extends Component {
+  static initProps(props) {
+    super.initProps(props);
+
+    props.className = props.className || '';
+    props.buttonClassName = props.buttonClassName || '';
+    props.menuClassName = props.menuClassName || '';
+    props.label = props.label || '';
+    props.caretIcon = typeof props.caretIcon !== 'undefined' ? props.caretIcon : 'fas fa-caret-down';
+  }
+
+  init() {
+    this.showing = false;
+  }
+
+  view() {
+    const items = this.props.children ? listItems(this.props.children) : [];
+
+    return (
+      <div className={'ButtonGroup Dropdown dropdown ' + this.props.className + ' itemCount' + items.length + (this.showing ? ' open' : '')}>
+        {this.getButton()}
+        {this.getMenu(items)}
+      </div>
+    );
+  }
+
+  config(isInitialized) {
+    if (isInitialized) return;
+
+    // When opening the dropdown menu, work out if the menu goes beyond the
+    // bottom of the viewport. If it does, we will apply class to make it show
+    // above the toggle button instead of below it.
+    this.$().on('shown.bs.dropdown', () => {
+      this.showing = true;
+
+      if (this.props.onshow) {
+        this.props.onshow();
+      }
+
+      m.redraw();
+
+      const $menu = this.$('.Dropdown-menu');
+      const isRight = $menu.hasClass('Dropdown-menu--right');
+
+      $menu.removeClass('Dropdown-menu--top Dropdown-menu--right');
+
+      $menu.toggleClass(
+        'Dropdown-menu--top',
+        $menu.offset().top + $menu.height() > $(window).scrollTop() + $(window).height()
+      );
+
+      if ($menu.offset().top < 0) {
+        $menu.removeClass('Dropdown-menu--top');
+      }
+
+      $menu.toggleClass(
+        'Dropdown-menu--right',
+        isRight || $menu.offset().left + $menu.width() > $(window).scrollLeft() + $(window).width()
+      );
+    });
+
+    this.$().on('hidden.bs.dropdown', () => {
+      this.showing = false;
+
+      if (this.props.onhide) {
+        this.props.onhide();
+      }
+
+      m.redraw();
+    });
+  }
+
+  /**
+   * Get the template for the button.
+   *
+   * @return {*}
+   * @protected
+   */
+  getButton() {
+    return (
+      <button
+        className={'Dropdown-toggle ' + this.props.buttonClassName}
+        data-toggle="dropdown"
+        onclick={this.props.onclick}>
+        {this.getButtonContent()}
+      </button>
+    );
+  }
+
+  /**
+   * Get the template for the button's content.
+   *
+   * @return {*}
+   * @protected
+   */
+  getButtonContent() {
+    return [
+      this.props.icon ? icon(this.props.icon, {className: 'Button-icon'}) : '',
+      <span className="Button-label">{this.props.label}</span>,
+      this.props.caretIcon ? icon(this.props.caretIcon, {className: 'Button-caret'}) : ''
+    ];
+  }
+
+  getMenu(items) {
+    return (
+      <ul className={'Dropdown-menu dropdown-menu ' + this.props.menuClassName}>
+        {items}
+      </ul>
+    );
+  }
+}

js/src/common/components/FieldSet.js

@@ -0,0 +1,22 @@
+import Component from '../Component';
+import listItems from '../helpers/listItems';
+
+/**
+ * The `FieldSet` component defines a collection of fields, displayed in a list
+ * underneath a title. Accepted properties are:
+ *
+ * - `className` The class name for the fieldset.
+ * - `label` The title of this group of fields.
+ *
+ * The children should be an array of items to show in the fieldset.
+ */
+export default class FieldSet extends Component {
+  view() {
+    return (
+      <fieldset className={this.props.className}>
+        <legend>{this.props.label}</legend>
+        <ul>{listItems(this.props.children)}</ul>
+      </fieldset>
+    );
+  }
+}

js/src/common/components/GroupBadge.js

@@ -0,0 +1,16 @@
+import Badge from './Badge';
+
+export default class GroupBadge extends Badge {
+  static initProps(props) {
+    super.initProps(props);
+
+    if (props.group) {
+      props.icon = props.group.icon();
+      props.style = {backgroundColor: props.group.color()};
+      props.label = typeof props.label === 'undefined' ? props.group.nameSingular() : props.label;
+      props.type = 'group--' + props.group.id();
+
+      delete props.group;
+    }
+  }
+}

js/src/common/components/LinkButton.js

@@ -0,0 +1,40 @@
+import Button from './Button';
+
+/**
+ * The `LinkButton` component defines a `Button` which links to a route.
+ *
+ * ### Props
+ *
+ * All of the props accepted by `Button`, plus:
+ *
+ * - `active` Whether or not the page that this button links to is currently
+ *   active.
+ * - `href` The URL to link to. If the current URL `m.route()` matches this,
+ *   the `active` prop will automatically be set to true.
+ */
+export default class LinkButton extends Button {
+  static initProps(props) {
+    props.active = this.isActive(props);
+    props.config = props.config || m.route;
+  }
+
+  view() {
+    const vdom = super.view();
+
+    vdom.tag = 'a';
+
+    return vdom;
+  }
+
+  /**
+   * Determine whether a component with the given props is 'active'.
+   *
+   * @param {Object} props
+   * @return {Boolean}
+   */
+  static isActive(props) {
+    return typeof props.active !== 'undefined'
+      ? props.active
+      : m.route() === props.href;
+  }
+}

js/src/common/components/LoadingIndicator.js

@@ -0,0 +1,36 @@
+import Component from '../Component';
+import { Spinner } from 'spin.js';
+
+/**
+ * The `LoadingIndicator` component displays a loading spinner with spin.js. It
+ * may have the following special props:
+ *
+ * - `size` The spin.js size preset to use. Defaults to 'small'.
+ *
+ * All other props will be assigned as attributes on the element.
+ */
+export default class LoadingIndicator extends Component {
+  view() {
+    const attrs = Object.assign({}, this.props);
+
+    attrs.className = 'LoadingIndicator ' + (attrs.className || '');
+    delete attrs.size;
+
+    return <div {...attrs}>{m.trust('&nbsp;')}</div>;
+  }
+
+  config() {
+    const options = { zIndex: 'auto', color: this.$().css('color') };
+
+    switch (this.props.size) {
+      case 'large':
+        Object.assign(options, { lines: 10, length: 8, width: 4, radius: 8 });
+        break;
+
+      default:
+        Object.assign(options, { lines: 8, length: 4, width: 3, radius: 5 });
+    }
+
+    new Spinner(options).spin(this.element);
+  }
+}

js/src/common/components/Modal.js

@@ -0,0 +1,139 @@
+import Component from '../Component';
+import Alert from './Alert';
+import Button from './Button';
+
+/**
+ * The `Modal` component displays a modal dialog, wrapped in a form. Subclasses
+ * should implement the `className`, `title`, and `content` methods.
+ *
+ * @abstract
+ */
+export default class Modal extends Component {
+  init() {
+    /**
+     * An alert component to show below the header.
+     *
+     * @type {Alert}
+     */
+    this.alert = null;
+  }
+
+  view() {
+    if (this.alert) {
+      this.alert.props.dismissible = false;
+    }
+
+    return (
+      <div className={'Modal modal-dialog ' + this.className()}>
+        <div className="Modal-content">
+          {this.isDismissible() ? (
+            <div className="Modal-close App-backControl">
+              {Button.component({
+                icon: 'fas fa-times',
+                onclick: this.hide.bind(this),
+                className: 'Button Button--icon Button--link'
+              })}
+            </div>
+          ) : ''}
+
+          <form onsubmit={this.onsubmit.bind(this)}>
+            <div className="Modal-header">
+              <h3 className="App-titleControl App-titleControl--text">{this.title()}</h3>
+            </div>
+
+            {alert ? <div className="Modal-alert">{this.alert}</div> : ''}
+
+            {this.content()}
+          </form>
+        </div>
+      </div>
+    );
+  }
+
+  /**
+   * Determine whether or not the modal should be dismissible via an 'x' button.
+   *
+   * @return {Boolean}
+   */
+  isDismissible() {
+    return true;
+  }
+
+  /**
+   * Get the class name to apply to the modal.
+   *
+   * @return {String}
+   * @abstract
+   */
+  className() {
+  }
+
+  /**
+   * Get the title of the modal dialog.
+   *
+   * @return {String}
+   * @abstract
+   */
+  title() {
+  }
+
+  /**
+   * Get the content of the modal.
+   *
+   * @return {VirtualElement}
+   * @abstract
+   */
+  content() {
+  }
+
+  /**
+   * Handle the modal form's submit event.
+   *
+   * @param {Event} e
+   */
+  onsubmit() {
+  }
+
+  /**
+   * Focus on the first input when the modal is ready to be used.
+   */
+  onready() {
+    this.$('form').find('input, select, textarea').first().focus().select();
+  }
+
+  onhide() {
+  }
+
+  /**
+   * Hide the modal.
+   */
+  hide() {
+    app.modal.close();
+  }
+
+  /**
+   * Stop loading.
+   */
+  loaded() {
+    this.loading = false;
+    m.redraw();
+  }
+
+  /**
+   * Show an alert describing an error returned from the API, and give focus to
+   * the first relevant field.
+   *
+   * @param {RequestError} error
+   */
+  onerror(error) {
+    this.alert = error.alert;
+
+    m.redraw();
+
+    if (error.status === 422 && error.response.errors) {
+      this.$('form [name=' + error.response.errors[0].source.pointer.replace('/data/attributes/', '') + ']').select();
+    } else {
+      this.onready();
+    }
+  }
+}

js/src/common/components/ModalManager.js

@@ -0,0 +1,106 @@
+import Component from '../Component';
+import Modal from './Modal';
+
+/**
+ * The `ModalManager` component manages a modal dialog. Only one modal dialog
+ * can be shown at once; loading a new component into the ModalManager will
+ * overwrite the previous one.
+ */
+export default class ModalManager extends Component {
+  init() {
+    this.showing = false;
+    this.component = null;
+  }
+
+  view() {
+    return (
+      <div className="ModalManager modal fade">
+        {this.component && this.component.render()}
+      </div>
+    );
+  }
+
+  config(isInitialized, context) {
+    if (isInitialized) return;
+
+    // Since this component is 'above' the content of the page (that is, it is a
+    // part of the global UI that persists between routes), we will flag the DOM
+    // to be retained across route changes.
+    context.retain = true;
+
+    this.$()
+      .on('hidden.bs.modal', this.clear.bind(this))
+      .on('shown.bs.modal', this.onready.bind(this));
+  }
+
+  /**
+   * Show a modal dialog.
+   *
+   * @param {Modal} component
+   * @public
+   */
+  show(component) {
+    if (!(component instanceof Modal)) {
+      throw new Error('The ModalManager component can only show Modal components');
+    }
+
+    clearTimeout(this.hideTimeout);
+
+    this.showing = true;
+    this.component = component;
+
+    app.current.retain = true;
+
+    m.redraw(true);
+
+    this.$().modal({backdrop: this.component.isDismissible() ? true : 'static'}).modal('show');
+    this.onready();
+  }
+
+  /**
+   * Close the modal dialog.
+   *
+   * @public
+   */
+  close() {
+    if (!this.showing) return;
+
+    // Don't hide the modal immediately, because if the consumer happens to call
+    // the `show` method straight after to show another modal dialog, it will
+    // cause Bootstrap's modal JS to misbehave. Instead we will wait for a tiny
+    // bit to give the `show` method the opportunity to prevent this from going
+    // ahead.
+    this.hideTimeout = setTimeout(() => {
+      this.$().modal('hide');
+      this.showing = false;
+    });
+  }
+
+  /**
+   * Clear content from the modal area.
+   *
+   * @protected
+   */
+  clear() {
+    if (this.component) {
+      this.component.onhide();
+    }
+
+    this.component = null;
+
+    app.current.retain = false;
+
+    m.lazyRedraw();
+  }
+
+  /**
+   * When the modal dialog is ready to be used, tell it!
+   *
+   * @protected
+   */
+  onready() {
+    if (this.component && this.component.onready) {
+      this.component.onready(this.$());
+    }
+  }
+}

js/src/common/components/Navigation.js

@@ -0,0 +1,106 @@
+import Component from '../Component';
+import Button from './Button';
+import LinkButton from './LinkButton';
+
+/**
+ * The `Navigation` component displays a set of navigation buttons. Typically
+ * this is just a back button which pops the app's History. If the user is on
+ * the root page and there is no history to pop, then in some instances it may
+ * show a button that toggles the app's drawer.
+ *
+ * If the app has a pane, it will also include a 'pin' button which toggles the
+ * pinned state of the pane.
+ *
+ * Accepts the following props:
+ *
+ * - `className` The name of a class to set on the root element.
+ * - `drawer` Whether or not to show a button to toggle the app's drawer if
+ *   there is no more history to pop.
+ */
+export default class Navigation extends Component {
+  view() {
+    const {history, pane} = app;
+
+    return (
+      <div className={'Navigation ButtonGroup ' + (this.props.className || '')}
+        onmouseenter={pane && pane.show.bind(pane)}
+        onmouseleave={pane && pane.onmouseleave.bind(pane)}>
+        {history.canGoBack()
+          ? [this.getBackButton(), this.getPaneButton()]
+          : this.getDrawerButton()}
+      </div>
+    );
+  }
+
+  config(isInitialized, context) {
+    // Since this component is 'above' the content of the page (that is, it is a
+    // part of the global UI that persists between routes), we will flag the DOM
+    // to be retained across route changes.
+    context.retain = true;
+  }
+
+  /**
+   * Get the back button.
+   *
+   * @return {Object}
+   * @protected
+   */
+  getBackButton() {
+    const {history} = app;
+    const previous = history.getPrevious() || {};
+
+    return LinkButton.component({
+      className: 'Button Navigation-back Button--icon',
+      href: history.backUrl(),
+      icon: 'fas fa-chevron-left',
+      title: previous.title,
+      config: () => {},
+      onclick: e => {
+        if (e.shiftKey || e.ctrlKey || e.metaKey || e.which === 2) return;
+        e.preventDefault();
+        history.back();
+      }
+    });
+  }
+
+  /**
+   * Get the pane pinned toggle button.
+   *
+   * @return {Object|String}
+   * @protected
+   */
+  getPaneButton() {
+    const {pane} = app;
+
+    if (!pane || !pane.active) return '';
+
+    return Button.component({
+      className: 'Button Button--icon Navigation-pin' + (pane.pinned ? ' active' : ''),
+      onclick: pane.togglePinned.bind(pane),
+      icon: 'fas fa-thumbtack'
+    });
+  }
+
+  /**
+   * Get the drawer toggle button.
+   *
+   * @return {Object|String}
+   * @protected
+   */
+  getDrawerButton() {
+    if (!this.props.drawer) return '';
+
+    const {drawer} = app;
+    const user = app.session.user;
+
+    return Button.component({
+      className: 'Button Button--icon Navigation-drawer' +
+        (user && user.newNotificationsCount() ? ' new' : ''),
+      onclick: e => {
+        e.stopPropagation();
+        drawer.show();
+      },
+      icon: 'fas fa-bars'
+    });
+  }
+}

js/src/common/components/Placeholder.js

@@ -0,0 +1,19 @@
+import Component from '../Component';
+
+/**
+ * The `Placeholder` component displays a muted text with some call to action,
+ * usually used as an empty state.
+ *
+ * ### Props
+ *
+ * - `text`
+ */
+export default class Placeholder extends Component {
+  view() {
+    return (
+      <div className="Placeholder">
+        <p>{this.props.text}</p>
+      </div>
+    );
+  }
+}

js/src/common/components/RequestErrorModal.js

@@ -0,0 +1,30 @@
+import Modal from './Modal';
+
+export default class RequestErrorModal extends Modal {
+  className() {
+    return 'RequestErrorModal Modal--large';
+  }
+
+  title() {
+    return this.props.error.xhr
+      ? this.props.error.xhr.status+' '+this.props.error.xhr.statusText
+      : '';
+  }
+
+  content() {
+    let responseText;
+
+    try {
+      responseText = JSON.stringify(JSON.parse(this.props.error.responseText), null, 2);
+    } catch (e) {
+      responseText = this.props.error.responseText;
+    }
+
+    return <div className="Modal-body">
+      <pre>
+        {this.props.error.options.method} {this.props.error.options.url}<br/><br/>
+        {responseText}
+      </pre>
+    </div>;
+  }
+}

js/src/common/components/Select.js

@@ -0,0 +1,25 @@
+import Component from '../Component';
+import icon from '../helpers/icon';
+
+/**
+ * The `Select` component displays a <select> input, surrounded with some extra
+ * elements for styling. It accepts the following props:
+ *
+ * - `options` A map of option values to labels.
+ * - `onchange` A callback to run when the selected value is changed.
+ * - `value` The value of the selected option.
+ */
+export default class Select extends Component {
+  view() {
+    const {options, onchange, value} = this.props;
+
+    return (
+      <span className="Select">
+        <select className="Select-input FormControl" onchange={onchange ? m.withAttr('value', onchange.bind(this)) : undefined} value={value}>
+          {Object.keys(options).map(key => <option value={key}>{options[key]}</option>)}
+        </select>
+        {icon('fas fa-sort', {className: 'Select-caret'})}
+      </span>
+    );
+  }
+}

js/src/common/components/SelectDropdown.js

@@ -0,0 +1,34 @@
+import Dropdown from './Dropdown';
+import icon from '../helpers/icon';
+
+/**
+ * The `SelectDropdown` component is the same as a `Dropdown`, except the toggle
+ * button's label is set as the label of the first child which has a truthy
+ * `active` prop.
+ *
+ * ### Props
+ *
+ * - `caretIcon`
+ * - `defaultLabel`
+ */
+export default class SelectDropdown extends Dropdown {
+  static initProps(props) {
+    props.caretIcon = typeof props.caretIcon !== 'undefined' ? props.caretIcon : 'fas fa-sort';
+
+    super.initProps(props);
+
+    props.className += ' Dropdown--select';
+  }
+
+  getButtonContent() {
+    const activeChild = this.props.children.filter(child => child.props.active)[0];
+    let label = activeChild && activeChild.props.children || this.props.defaultLabel;
+
+    if (label instanceof Array) label = label[0];
+
+    return [
+      <span className="Button-label">{label}</span>,
+      icon(this.props.caretIcon, {className: 'Button-caret'})
+    ];
+  }
+}

js/src/common/components/Separator.js

@@ -0,0 +1,14 @@
+import Component from '../Component';
+
+/**
+ * The `Separator` component defines a menu separator item.
+ */
+class Separator extends Component {
+  view() {
+    return <li className="Dropdown-separator"/>;
+  }
+}
+
+Separator.isListItem = true;
+
+export default Separator;

js/src/common/components/SplitDropdown.js

@@ -0,0 +1,50 @@
+import Dropdown from './Dropdown';
+import Button from './Button';
+import icon from '../helpers/icon';
+
+/**
+ * The `SplitDropdown` component is similar to `Dropdown`, but the first child
+ * is displayed as its own button prior to the toggle button.
+ */
+export default class SplitDropdown extends Dropdown {
+  static initProps(props) {
+    super.initProps(props);
+
+    props.className += ' Dropdown--split';
+    props.menuClassName += ' Dropdown-menu--right';
+  }
+
+  getButton() {
+    // Make a copy of the props of the first child component. We will assign
+    // these props to a new button, so that it has exactly the same behaviour as
+    // the first child.
+    const firstChild = this.getFirstChild();
+    const buttonProps = Object.assign({}, firstChild.props);
+    buttonProps.className = (buttonProps.className || '') + ' SplitDropdown-button Button ' + this.props.buttonClassName;
+
+    return [
+      Button.component(buttonProps),
+      <button
+        className={'Dropdown-toggle Button Button--icon ' + this.props.buttonClassName}
+        data-toggle="dropdown">
+        {icon(this.props.icon, {className: 'Button-icon'})}
+        {icon('fas fa-caret-down', {className: 'Button-caret'})}
+      </button>
+    ];
+  }
+
+  /**
+   * Get the first child. If the first child is an array, the first item in that
+   * array will be returned.
+   *
+   * @return {*}
+   * @protected
+   */
+  getFirstChild() {
+    let firstChild = this.props.children;
+
+    while (firstChild instanceof Array) firstChild = firstChild[0];
+
+    return firstChild;
+  }
+}

js/src/common/components/Switch.js

@@ -0,0 +1,17 @@
+import Checkbox from './Checkbox';
+
+/**
+ * The `Switch` component is a `Checkbox`, but with a switch display instead of
+ * a tick/cross one.
+ */
+export default class Switch extends Checkbox {
+  static initProps(props) {
+    super.initProps(props);
+
+    props.className = (props.className || '') + ' Checkbox--switch';
+  }
+
+  getDisplay() {
+    return this.loading ? super.getDisplay() : '';
+  }
+}

js/src/common/extend.js

@@ -0,0 +1,65 @@
+/**
+ * Extend an object's method by running its output through a mutating callback
+ * every time it is called.
+ *
+ * The callback accepts the method's return value and should perform any
+ * mutations directly on this value. For this reason, this function will not be
+ * effective on methods which return scalar values (numbers, strings, booleans).
+ *
+ * Care should be taken to extend the correct object – in most cases, a class'
+ * prototype will be the desired target of extension, not the class itself.
+ *
+ * @example
+ * extend(Discussion.prototype, 'badges', function(badges) {
+ *   // do something with `badges`
+ * });
+ *
+ * @param {Object} object The object that owns the method
+ * @param {String} method The name of the method to extend
+ * @param {function} callback A callback which mutates the method's output
+ */
+export function extend(object, method, callback) {
+  const original = object[method];
+
+  object[method] = function(...args) {
+    const value = original ? original.apply(this, args) : undefined;
+
+    callback.apply(this, [value].concat(args));
+
+    return value;
+  };
+
+  Object.assign(object[method], original);
+}
+
+/**
+ * Override an object's method by replacing it with a new function, so that the
+ * new function will be run every time the object's method is called.
+ *
+ * The replacement function accepts the original method as its first argument,
+ * which is like a call to 'super'. Any arguments passed to the original method
+ * are also passed to the replacement.
+ *
+ * Care should be taken to extend the correct object – in most cases, a class'
+ * prototype will be the desired target of extension, not the class itself.
+ *
+ * @example
+ * override(Discussion.prototype, 'badges', function(original) {
+ *   const badges = original();
+ *   // do something with badges
+ *   return badges;
+ * });
+ *
+ * @param {Object} object The object that owns the method
+ * @param {String} method The name of the method to override
+ * @param {function} newMethod The method to replace it with
+ */
+export function override(object, method, newMethod) {
+  const original = object[method];
+
+  object[method] = function(...args) {
+    return newMethod.apply(this, [original.bind(this)].concat(args));
+  };
+
+  Object.assign(object[method], original);
+}

js/src/common/helpers/avatar.js

@@ -0,0 +1,36 @@
+/**
+ * The `avatar` helper displays a user's avatar.
+ *
+ * @param {User} user
+ * @param {Object} attrs Attributes to apply to the avatar element
+ * @return {Object}
+ */
+export default function avatar(user, attrs = {}) {
+  attrs.className = 'Avatar ' + (attrs.className || '');
+  let content = '';
+
+  // If the `title` attribute is set to null or false, we don't want to give the
+  // avatar a title. On the other hand, if it hasn't been given at all, we can
+  // safely default it to the user's username.
+  const hasTitle = attrs.title === 'undefined' || attrs.title;
+  if (!hasTitle) delete attrs.title;
+
+  // If a user has been passed, then we will set up an avatar using their
+  // uploaded image, or the first letter of their username if they haven't
+  // uploaded one.
+  if (user) {
+    const username = user.displayName() || '?';
+    const avatarUrl = user.avatarUrl();
+
+    if (hasTitle) attrs.title = attrs.title || username;
+
+    if (avatarUrl) {
+      return <img {...attrs} src={avatarUrl}/>;
+    }
+
+    content = username.charAt(0).toUpperCase();
+    attrs.style = {background: user.color()};
+  }
+
+  return <span {...attrs}>{content}</span>;
+}

js/src/common/helpers/fullTime.js

@@ -0,0 +1,15 @@
+/**
+ * The `fullTime` helper displays a formatted time string wrapped in a <time>
+ * tag.
+ *
+ * @param {Date} time
+ * @return {Object}
+ */
+export default function fullTime(time) {
+  const mo = moment(time);
+
+  const datetime = mo.format();
+  const full = mo.format('LLLL');
+
+  return <time pubdate datetime={datetime}>{full}</time>;
+}

js/src/common/helpers/highlight.js

@@ -0,0 +1,37 @@
+import { truncate } from '../utils/string';
+
+/**
+ * The `highlight` helper searches for a word phrase in a string, and wraps
+ * matches with the <mark> tag.
+ *
+ * @param {String} string The string to highlight.
+ * @param {String|RegExp} phrase The word or words to highlight.
+ * @param {Integer} [length] The number of characters to truncate the string to.
+ *     The string will be truncated surrounding the first match.
+ * @return {Object}
+ */
+export default function highlight(string, phrase, length) {
+  if (!phrase && !length) return string;
+
+  // Convert the word phrase into a global regular expression (if it isn't
+  // already) so we can search the string for matched.
+  const regexp = phrase instanceof RegExp ? phrase : new RegExp(phrase, 'gi');
+
+  let highlighted = string;
+  let start = 0;
+
+  // If a length was given, the truncate the string surrounding the first match.
+  if (length) {
+    if (phrase) start = Math.max(0, string.search(regexp) - length / 2);
+
+    highlighted = truncate(highlighted, length, start);
+  }
+
+  // Convert the string into HTML entities, then highlight all matches with
+  // <mark> tags. Then we will return the result as a trusted HTML string.
+  highlighted = $('<div/>').text(highlighted).html();
+
+  if (phrase) highlighted = highlighted.replace(regexp, '<mark>$&</mark>');
+
+  return m.trust(highlighted);
+}

js/src/common/helpers/humanTime.js

@@ -0,0 +1,19 @@
+import humanTimeUtil from '../utils/humanTime';
+
+/**
+ * The `humanTime` helper displays a time in a human-friendly time-ago format
+ * (e.g. '12 days ago'), wrapped in a <time> tag with other information about
+ * the time.
+ *
+ * @param {Date} time
+ * @return {Object}
+ */
+export default function humanTime(time) {
+  const mo = moment(time);
+
+  const datetime = mo.format();
+  const full = mo.format('LLLL');
+  const ago = humanTimeUtil(time);
+
+  return <time pubdate datetime={datetime} title={full} data-humantime>{ago}</time>;
+}

js/src/common/helpers/icon.js

@@ -0,0 +1,12 @@
+/**
+ * The `icon` helper displays an icon.
+ *
+ * @param {String} fontClass The full icon class, prefix and the icon’s name.
+ * @param {Object} attrs Any other attributes to apply.
+ * @return {Object}
+ */
+export default function icon(fontClass, attrs = {}) {
+  attrs.className = 'icon ' + fontClass + ' ' + (attrs.className || '');
+
+  return <i {...attrs}/>;
+}

js/src/common/helpers/listItems.js

@@ -0,0 +1,53 @@
+import Separator from '../components/Separator';
+import classList from '../utils/classList';
+
+function isSeparator(item) {
+  return item && item.component === Separator;
+}
+
+function withoutUnnecessarySeparators(items) {
+  const newItems = [];
+  let prevItem;
+
+  items.forEach((item, i) => {
+    if (!isSeparator(item) || (prevItem && !isSeparator(prevItem) && i !== items.length - 1)) {
+      prevItem = item;
+      newItems.push(item);
+    }
+  });
+
+  return newItems;
+}
+
+/**
+ * The `listItems` helper wraps a collection of components in <li> tags,
+ * stripping out any unnecessary `Separator` components.
+ *
+ * @param {*} items
+ * @return {Array}
+ */
+export default function listItems(items) {
+  if (!(items instanceof Array)) items = [items];
+
+  return withoutUnnecessarySeparators(items).map(item => {
+    const isListItem = item.component && item.component.isListItem;
+    const active = item.component && item.component.isActive && item.component.isActive(item.props);
+    const className = item.props ? item.props.itemClassName : item.itemClassName;
+
+    if (isListItem) {
+      item.attrs = item.attrs || {};
+      item.attrs.key = item.attrs.key || item.itemName;
+    }
+
+    return isListItem
+      ? item
+      : <li className={classList([
+          (item.itemName ? 'item-' + item.itemName : ''),
+          className,
+          (active ? 'active' : '')
+        ])}
+          key={item.itemName}>
+          {item}
+        </li>;
+  });
+}

js/src/common/helpers/punctuateSeries.js

@@ -0,0 +1,35 @@
+/**
+ * The `punctuateSeries` helper formats a list of strings (e.g. names) to read
+ * fluently in the application's locale.
+ *
+ * ```js
+ * punctuateSeries(['Toby', 'Franz', 'Dominion']) // Toby, Franz, and Dominion
+ * ```
+ *
+ * @param {Array} items
+ * @return {VirtualElement}
+ */
+export default function punctuateSeries(items) {
+  if (items.length === 2) {
+    return app.translator.trans('core.lib.series.two_text', {
+      first: items[0],
+      second: items[1]
+    });
+  } else if (items.length >= 3) {
+    // If there are three or more items, we will join all but the first and
+    // last items with the equivalent of a comma, and then we will feed that
+    // into the translator along with the first and last item.
+    const second = items
+      .slice(1, items.length - 1)
+      .reduce((list, item) => list.concat([item, app.translator.trans('core.lib.series.glue_text')]), [])
+      .slice(0, -1);
+
+    return app.translator.trans('core.lib.series.three_text', {
+      first: items[0],
+      second,
+      third: items[items.length - 1]
+    });
+  }
+
+  return items;
+}

js/src/common/helpers/userOnline.js

@@ -0,0 +1,13 @@
+import icon from './icon';
+
+/**
+ * The `useronline` helper displays a green circle if the user is online
+ *
+ * @param {User} user
+ * @return {Object}
+ */
+export default function userOnline(user) {
+    if (user.lastSeenTime() && user.isOnline()) {
+        return <span className="UserOnline">{icon('fas fa-circle')}</span>;
+    }
+}

js/src/common/helpers/username.js

@@ -0,0 +1,12 @@
+/**
+ * The `username` helper displays a user's username in a <span class="username">
+ * tag. If the user doesn't exist, the username will be displayed as [deleted].
+ *
+ * @param {User} user
+ * @return {Object}
+ */
+export default function username(user) {
+  const name = (user && user.displayName()) || app.translator.trans('core.lib.username.deleted_text');
+
+  return <span className="username">{name}</span>;
+}

js/src/common/models/Discussion.js

@@ -0,0 +1,104 @@
+import Model from '../Model';
+import computed from '../utils/computed';
+import ItemList from '../utils/ItemList';
+import Badge from '../components/Badge';
+
+export default class Discussion extends Model {}
+
+Object.assign(Discussion.prototype, {
+  title: Model.attribute('title'),
+  slug: Model.attribute('slug'),
+
+  startTime: Model.attribute('startTime', Model.transformDate),
+  startUser: Model.hasOne('startUser'),
+  startPost: Model.hasOne('startPost'),
+
+  lastTime: Model.attribute('lastTime', Model.transformDate),
+  lastUser: Model.hasOne('lastUser'),
+  lastPost: Model.hasOne('lastPost'),
+  lastPostNumber: Model.attribute('lastPostNumber'),
+
+  commentsCount: Model.attribute('commentsCount'),
+  repliesCount: computed('commentsCount', commentsCount => Math.max(0, commentsCount - 1)),
+  posts: Model.hasMany('posts'),
+  mostRelevantPost: Model.hasOne('mostRelevantPost'),
+
+  readTime: Model.attribute('readTime', Model.transformDate),
+  readNumber: Model.attribute('readNumber'),
+  isUnread: computed('unreadCount', unreadCount => !!unreadCount),
+  isRead: computed('unreadCount', unreadCount => app.session.user && !unreadCount),
+
+  hideTime: Model.attribute('hideTime', Model.transformDate),
+  hideUser: Model.hasOne('hideUser'),
+  isHidden: computed('hideTime', hideTime => !!hideTime),
+
+  canReply: Model.attribute('canReply'),
+  canRename: Model.attribute('canRename'),
+  canHide: Model.attribute('canHide'),
+  canDelete: Model.attribute('canDelete'),
+
+  /**
+   * Remove a post from the discussion's posts relationship.
+   *
+   * @param {Integer} id The ID of the post to remove.
+   * @public
+   */
+  removePost(id) {
+    const relationships = this.data.relationships;
+    const posts = relationships && relationships.posts;
+
+    if (posts) {
+      posts.data.some((data, i) => {
+        if (id === data.id) {
+          posts.data.splice(i, 1);
+          return true;
+        }
+      });
+    }
+  },
+
+  /**
+   * Get the estimated number of unread posts in this discussion for the current
+   * user.
+   *
+   * @return {Integer}
+   * @public
+   */
+  unreadCount() {
+    const user = app.session.user;
+
+    if (user && user.readTime() < this.lastTime()) {
+      return Math.max(0, this.lastPostNumber() - (this.readNumber() || 0));
+    }
+
+    return 0;
+  },
+
+  /**
+   * Get the Badge components that apply to this discussion.
+   *
+   * @return {ItemList}
+   * @public
+   */
+  badges() {
+    const items = new ItemList();
+
+    if (this.isHidden()) {
+      items.add('hidden', <Badge type="hidden" icon="fas fa-trash" label={app.translator.trans('core.lib.badge.hidden_tooltip')}/>);
+    }
+
+    return items;
+  },
+
+  /**
+   * Get a list of all of the post IDs in this discussion.
+   *
+   * @return {Array}
+   * @public
+   */
+  postIds() {
+    const posts = this.data.relationships.posts;
+
+    return posts ? posts.data.map(link => link.id) : [];
+  }
+});

js/src/common/models/Forum.js

@@ -0,0 +1,7 @@
+import Model from '../Model';
+
+export default class Forum extends Model {
+  apiEndpoint() {
+    return '/';
+  }
+}

js/src/common/models/Group.js

@@ -0,0 +1,16 @@
+import Model from '../Model';
+
+class Group extends Model {}
+
+Object.assign(Group.prototype, {
+  nameSingular: Model.attribute('nameSingular'),
+  namePlural: Model.attribute('namePlural'),
+  color: Model.attribute('color'),
+  icon: Model.attribute('icon')
+});
+
+Group.ADMINISTRATOR_ID = '1';
+Group.GUEST_ID = '2';
+Group.MEMBER_ID = '3';
+
+export default Group;

js/src/common/models/Notification.js

@@ -0,0 +1,19 @@
+import Model from '../Model';
+import computed from '../utils/computed';
+
+export default class Notification extends Model {}
+
+Object.assign(Notification.prototype, {
+  contentType: Model.attribute('contentType'),
+  subjectId: Model.attribute('subjectId'),
+  content: Model.attribute('content'),
+  time: Model.attribute('time', Model.date),
+
+  isRead: Model.attribute('isRead'),
+  unreadCount: Model.attribute('unreadCount'),
+  additionalUnreadCount: computed('unreadCount', unreadCount => Math.max(0, unreadCount - 1)),
+
+  user: Model.hasOne('user'),
+  sender: Model.hasOne('sender'),
+  subject: Model.hasOne('subject')
+});

js/src/common/models/Post.js

@@ -0,0 +1,28 @@
+import Model from '../Model';
+import computed from '../utils/computed';
+import { getPlainContent } from '../utils/string';
+
+export default class Post extends Model {}
+
+Object.assign(Post.prototype, {
+  number: Model.attribute('number'),
+  discussion: Model.hasOne('discussion'),
+
+  time: Model.attribute('time', Model.transformDate),
+  user: Model.hasOne('user'),
+  contentType: Model.attribute('contentType'),
+  content: Model.attribute('content'),
+  contentHtml: Model.attribute('contentHtml'),
+  contentPlain: computed('contentHtml', getPlainContent),
+
+  editTime: Model.attribute('editTime', Model.transformDate),
+  editUser: Model.hasOne('editUser'),
+  isEdited: computed('editTime', editTime => !!editTime),
+
+  hideTime: Model.attribute('hideTime', Model.transformDate),
+  hideUser: Model.hasOne('hideUser'),
+  isHidden: computed('hideTime', hideTime => !!hideTime),
+
+  canEdit: Model.attribute('canEdit'),
+  canDelete: Model.attribute('canDelete')
+});

js/src/common/models/User.js

@@ -0,0 +1,110 @@
+/*global ColorThief*/
+
+import Model from '../Model';
+import stringToColor from '../utils/stringToColor';
+import ItemList from '../utils/ItemList';
+import computed from '../utils/computed';
+import GroupBadge from '../components/GroupBadge';
+
+export default class User extends Model {}
+
+Object.assign(User.prototype, {
+  username: Model.attribute('username'),
+  displayName: Model.attribute('displayName'),
+  email: Model.attribute('email'),
+  isActivated: Model.attribute('isActivated'),
+  password: Model.attribute('password'),
+
+  avatarUrl: Model.attribute('avatarUrl'),
+  preferences: Model.attribute('preferences'),
+  groups: Model.hasMany('groups'),
+
+  joinTime: Model.attribute('joinTime', Model.transformDate),
+  lastSeenTime: Model.attribute('lastSeenTime', Model.transformDate),
+  readTime: Model.attribute('readTime', Model.transformDate),
+  unreadNotificationsCount: Model.attribute('unreadNotificationsCount'),
+  newNotificationsCount: Model.attribute('newNotificationsCount'),
+
+  discussionsCount: Model.attribute('discussionsCount'),
+  commentsCount: Model.attribute('commentsCount'),
+
+  canEdit: Model.attribute('canEdit'),
+  canDelete: Model.attribute('canDelete'),
+
+  avatarColor: null,
+  color: computed('username', 'avatarUrl', 'avatarColor', function(username, avatarUrl, avatarColor) {
+    // If we've already calculated and cached the dominant color of the user's
+    // avatar, then we can return that in RGB format. If we haven't, we'll want
+    // to calculate it. Unless the user doesn't have an avatar, in which case
+    // we generate a color from their username.
+    if (avatarColor) {
+      return 'rgb(' + avatarColor.join(', ') + ')';
+    } else if (avatarUrl) {
+      this.calculateAvatarColor();
+      return '';
+    }
+
+    return '#' + stringToColor(username);
+  }),
+
+  /**
+   * Check whether or not the user has been seen in the last 5 minutes.
+   *
+   * @return {Boolean}
+   * @public
+   */
+  isOnline() {
+    return this.lastSeenTime() > moment().subtract(5, 'minutes').toDate();
+  },
+
+  /**
+   * Get the Badge components that apply to this user.
+   *
+   * @return {ItemList}
+   */
+  badges() {
+    const items = new ItemList();
+    const groups = this.groups();
+
+    if (groups) {
+      groups.forEach(group => {
+        items.add('group' + group.id(), GroupBadge.component({group}));
+      });
+    }
+
+    return items;
+  },
+
+  /**
+   * Calculate the dominant color of the user's avatar. The dominant color will
+   * be set to the `avatarColor` property once it has been calculated.
+   *
+   * @protected
+   */
+  calculateAvatarColor() {
+    const image = new Image();
+    const user = this;
+
+    image.onload = function() {
+      const colorThief = new ColorThief();
+      user.avatarColor = colorThief.getColor(this);
+      user.freshness = new Date();
+      m.redraw();
+    };
+    image.src = this.avatarUrl();
+  },
+
+  /**
+   * Update the user's preferences.
+   *
+   * @param {Object} newPreferences
+   * @return {Promise}
+   */
+  savePreferences(newPreferences) {
+    const preferences = this.preferences();
+
+    Object.assign(preferences, newPreferences);
+
+    return this.save({preferences});
+  }
+});

js/src/common/utils/Drawer.js

@@ -0,0 +1,54 @@
+/**
+ * The `Drawer` class controls the page's drawer. The drawer is the area the
+ * slides out from the left on mobile devices; it contains the header and the
+ * footer.
+ */
+export default class Drawer {
+  constructor() {
+    // Set up an event handler so that whenever the content area is tapped,
+    // the drawer will close.
+    $('#content').click(e => {
+      if (this.isOpen()) {
+        e.preventDefault();
+        this.hide();
+      }
+    });
+  }
+
+  /**
+   * Check whether or not the drawer is currently open.
+   *
+   * @return {Boolean}
+   * @public
+   */
+  isOpen() {
+    return $('#app').hasClass('drawerOpen');
+  }
+
+  /**
+   * Hide the drawer.
+   *
+   * @public
+   */
+  hide() {
+    $('#app').removeClass('drawerOpen');
+
+    if (this.$backdrop) this.$backdrop.remove();
+  }
+
+  /**
+   * Show the drawer.
+   *
+   * @public
+   */
+  show() {
+    $('#app').addClass('drawerOpen');
+
+    this.$backdrop = $('<div/>')
+      .addClass('drawer-backdrop fade')
+      .appendTo('body')
+      .click(() => this.hide());
+
+    setTimeout(() => this.$backdrop.addClass('in'));
+  }
+}

js/src/common/utils/ItemList.js

@@ -0,0 +1,148 @@
+class Item {
+  constructor(content, priority) {
+    this.content = content;
+    this.priority = priority;
+  }
+}
+
+/**
+ * The `ItemList` class collects items and then arranges them into an array
+ * by priority.
+ */
+export default class ItemList {
+  constructor() {
+    /**
+     * The items in the list.
+     *
+     * @type {Object}
+     * @public
+     */
+    this.items = {};
+  }
+
+  /**
+   * Check whether the list is empty.
+   *
+   * @returns {boolean}
+   * @public
+   */
+  isEmpty() {
+    for (const i in this.items) {
+      if(this.items.hasOwnProperty(i)) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+
+  /**
+   * Check whether an item is present in the list.
+   *
+   * @param key
+   * @returns {boolean}
+   */
+  has(key) {
+    return !!this.items[key];
+  }
+
+  /**
+   * Get the content of an item.
+   *
+   * @param {String} key
+   * @return {*}
+   * @public
+   */
+  get(key) {
+    return this.items[key].content;
+  }
+
+  /**
+   * Add an item to the list.
+   *
+   * @param {String} key A unique key for the item.
+   * @param {*} content The item's content.
+   * @param {Integer} [priority] The priority of the item. Items with a higher
+   *     priority will be positioned before items with a lower priority.
+   * @public
+   */
+  add(key, content, priority = 0) {
+    this.items[key] = new Item(content, priority);
+  }
+
+  /**
+   * Replace an item in the list, only if it is already present.
+   *
+   * @param {String} key
+   * @param {*} [content]
+   * @param {Integer} [priority]
+   * @public
+   */
+  replace(key, content = null, priority = null) {
+    if (this.items[key]) {
+      if (content !== null) {
+        this.items[key].content = content;
+      }
+
+      if (priority !== null) {
+        this.items[key].priority = priority;
+      }
+    }
+  }
+
+  /**
+   * Remove an item from the list.
+   *
+   * @param {String} key
+   * @public
+   */
+  remove(key) {
+    delete this.items[key];
+  }
+
+  /**
+   * Merge another list's items into this one.
+   *
+   * @param {ItemList} items
+   * @public
+   */
+  merge(items) {
+    for (const i in items.items) {
+      if (items.items.hasOwnProperty(i) && items.items[i] instanceof Item) {
+        this.items[i] = items.items[i];
+      }
+    }
+  }
+
+  /**
+   * Convert the list into an array of item content arranged by priority. Each
+   * item's content will be assigned an `itemName` property equal to the item's
+   * unique key.
+   *
+   * @return {Array}
+   * @public
+   */
+  toArray() {
+    const items = [];
+
+    for (const i in this.items) {
+      if (this.items.hasOwnProperty(i) && this.items[i] instanceof Item) {
+        this.items[i].content = Object(this.items[i].content);
+
+        this.items[i].content.itemName = i;
+        items.push(this.items[i]);
+        this.items[i].key = items.length;
+      }
+    }
+
+    return items.sort((a, b) => {
+      if (a.priority === b.priority) {
+        return a.key - b.key;
+      } else if (a.priority > b.priority) {
+        return -1;
+      }
+      return 1;
+    }).map(item => item.content);
+  }
+}
+

js/src/common/utils/RequestError.js

@@ -0,0 +1,16 @@
+export default class RequestError {
+  constructor(status, responseText, options, xhr) {
+    this.status = status;
+    this.responseText = responseText;
+    this.options = options;
+    this.xhr = xhr;
+
+    try {
+      this.response = JSON.parse(responseText);
+    } catch (e) {
+      this.response = null;
+    }
+
+    this.alert = null;
+  }
+}

js/src/common/utils/ScrollListener.js

@@ -0,0 +1,73 @@
+const scroll = window.requestAnimationFrame ||
+  window.webkitRequestAnimationFrame ||
+  window.mozRequestAnimationFrame ||
+  window.msRequestAnimationFrame ||
+  window.oRequestAnimationFrame ||
+  (callback => window.setTimeout(callback, 1000 / 60));
+
+/**
+ * The `ScrollListener` class sets up a listener that handles window scroll
+ * events.
+ */
+export default class ScrollListener {
+  /**
+   * @param {Function} callback The callback to run when the scroll position
+   *     changes.
+   * @public
+   */
+  constructor(callback) {
+    this.callback = callback;
+    this.lastTop = -1;
+  }
+
+  /**
+   * On each animation frame, as long as the listener is active, run the
+   * `update` method.
+   *
+   * @protected
+   */
+  loop() {
+    if (!this.active) return;
+
+    this.update();
+
+    scroll(this.loop.bind(this));
+  }
+
+  /**
+   * Check if the scroll position has changed; if it has, run the handler.
+   *
+   * @param {Boolean} [force=false] Whether or not to force the handler to be
+   *     run, even if the scroll position hasn't changed.
+   * @public
+   */
+  update(force) {
+    const top = window.pageYOffset;
+
+    if (this.lastTop !== top || force) {
+      this.callback(top);
+      this.lastTop = top;
+    }
+  }
+
+  /**
+   * Start listening to and handling the window's scroll position.
+   *
+   * @public
+   */
+  start() {
+    if (!this.active) {
+      this.active = true;
+      this.loop();
+    }
+  }
+
+  /**
+   * Stop listening to and handling the window's scroll position.
+   *
+   * @public
+   */
+  stop() {
+    this.active = false;
+  }
+}

js/src/common/utils/SubtreeRetainer.js

@@ -0,0 +1,68 @@
+/**
+ * The `SubtreeRetainer` class represents a Mithril virtual DOM subtree. It
+ * keeps track of a number of pieces of data, allowing the subtree to be
+ * retained if none of them have changed.
+ *
+ * @example
+ * // constructor
+ * this.subtree = new SubtreeRetainer(
+ *   () => this.props.post.freshness,
+ *   () => this.showing
+ * );
+ * this.subtree.check(() => this.props.user.freshness);
+ *
+ * // view
+ * this.subtree.retain() || 'expensive expression'
+ *
+ * @see https://lhorie.github.io/mithril/mithril.html#persisting-dom-elements-across-route-changes
+ */
+export default class SubtreeRetainer {
+  /**
+   * @param {...callbacks} callbacks Functions returning data to keep track of.
+   */
+  constructor(...callbacks) {
+    this.callbacks = callbacks;
+    this.data = {};
+  }
+
+  /**
+   * Return a virtual DOM directive that will retain a subtree if no data has
+   * changed since the last check.
+   *
+   * @return {Object|false}
+   * @public
+   */
+  retain() {
+    let needsRebuild = false;
+
+    this.callbacks.forEach((callback, i) => {
+      const result = callback();
+
+      if (result !== this.data[i]) {
+        this.data[i] = result;
+        needsRebuild = true;
+      }
+    });
+
+    return needsRebuild ? false : {subtree: 'retain'};
+  }
+
+  /**
+   * Add another callback to be checked.
+   *
+   * @param {...Function} callbacks
+   * @public
+   */
+  check(...callbacks) {
+    this.callbacks = this.callbacks.concat(callbacks);
+  }
+
+  /**
+   * Invalidate the subtree, forcing it to be rerendered.
+   *
+   * @public
+   */
+  invalidate() {
+    this.data = {};
+  }
+}

js/src/common/utils/abbreviateNumber.js

@@ -0,0 +1,20 @@
+/**
+ * The `abbreviateNumber` utility converts a number to a shorter localized form.
+ *
+ * @example
+ * abbreviateNumber(1234);
+ * // "1.2K"
+ *
+ * @param {Integer} number
+ * @return {String}
+ */
+export default function abbreviateNumber(number) {
+  // TODO: translation
+  if (number >= 1000000) {
+    return Math.floor(number / 1000000) + app.translator.trans('core.lib.number_suffix.mega_text');
+  } else if (number >= 1000) {
+    return Math.floor(number / 1000) + app.translator.trans('core.lib.number_suffix.kilo_text');
+  } else {
+    return number.toString();
+  }
+}

js/src/common/utils/anchorScroll.js

@@ -0,0 +1,21 @@
+/**
+ * The `anchorScroll` utility saves the scroll position relative to an element,
+ * and then restores it after a callback has been run.
+ *
+ * This is useful if a redraw will change the page's content above the viewport.
+ * Normally doing this will result in the content in the viewport being pushed
+ * down or pulled up. By wrapping the redraw with this utility, the scroll
+ * position can be anchor to an element that is in or below the viewport, so
+ * the content in the viewport will stay the same.
+ *
+ * @param {DOMElement} element The element to anchor the scroll position to.
+ * @param {Function} callback The callback to run that will change page content.
+ */
+export default function anchorScroll(element, callback) {
+  const $window = $(window);
+  const relativeScroll = $(element).offset().top - $window.scrollTop();
+
+  callback();
+
+  $window.scrollTop($(element).offset().top - relativeScroll);
+}

js/src/common/utils/classList.js

@@ -0,0 +1,26 @@
+/**
+ * The `classList` utility creates a list of class names by joining an object's
+ * keys, but only for values which are truthy.
+ *
+ * @example
+ * classList({ foo: true, bar: false, qux: 'qaz' });
+ * // "foo qux"
+ *
+ * @param {Object} classes
+ * @return {String}
+ */
+export default function classList(classes) {
+  let classNames;
+
+  if (classes instanceof Array) {
+    classNames = classes.filter(name => name);
+  } else {
+    classNames = [];
+
+    for (const i in classes) {
+      if (classes[i]) classNames.push(i);
+    }
+  }
+
+  return classNames.join(' ');
+}

js/src/common/utils/computed.js

@@ -0,0 +1,37 @@
+/**
+ * The `computed` utility creates a function that will cache its output until
+ * any of the dependent values are dirty.
+ *
+ * @param {...String} dependentKeys The keys of the dependent values.
+ * @param {function} compute The function which computes the value using the
+ *     dependent values.
+ * @return {Function}
+ */
+export default function computed(...dependentKeys) {
+  const keys = dependentKeys.slice(0, -1);
+  const compute = dependentKeys.slice(-1)[0];
+
+  const dependentValues = {};
+  let computedValue;
+
+  return function() {
+    let recompute = false;
+
+    // Read all of the dependent values. If any of them have changed since last
+    // time, then we'll want to recompute our output.
+    keys.forEach(key => {
+      const value = typeof this[key] === 'function' ? this[key]() : this[key];
+
+      if (dependentValues[key] !== value) {
+        recompute = true;
+        dependentValues[key] = value;
+      }
+    });
+
+    if (recompute) {
+      computedValue = compute.apply(this, keys.map(key => dependentValues[key]));
+    }
+
+    return computedValue;
+  };
+}

js/src/common/utils/evented.js

@@ -0,0 +1,81 @@
+/**
+ * The `evented` mixin provides methods allowing an object to trigger events,
+ * running externally registered event handlers.
+ */
+export default {
+  /**
+   * Arrays of registered event handlers, grouped by the event name.
+   *
+   * @type {Object}
+   * @protected
+   */
+  handlers: null,
+
+  /**
+   * Get all of the registered handlers for an event.
+   *
+   * @param {String} event The name of the event.
+   * @return {Array}
+   * @protected
+   */
+  getHandlers(event) {
+    this.handlers = this.handlers || {};
+
+    this.handlers[event] = this.handlers[event] || [];
+
+    return this.handlers[event];
+  },
+
+  /**
+   * Trigger an event.
+   *
+   * @param {String} event The name of the event.
+   * @param {...*} args Arguments to pass to event handlers.
+   * @public
+   */
+  trigger(event, ...args) {
+    this.getHandlers(event).forEach(handler => handler.apply(this, args));
+  },
+
+  /**
+   * Register an event handler.
+   *
+   * @param {String} event The name of the event.
+   * @param {function} handler The function to handle the event.
+   */
+  on(event, handler) {
+    this.getHandlers(event).push(handler);
+  },
+
+  /**
+   * Register an event handler so that it will run only once, and then
+   * unregister itself.
+   *
+   * @param {String} event The name of the event.
+   * @param {function} handler The function to handle the event.
+   */
+  one(event, handler) {
+    const wrapper = function() {
+      handler.apply(this, arguments);
+
+      this.off(event, wrapper);
+    };
+
+    this.getHandlers(event).push(wrapper);
+  },
+
+  /**
+   * Unregister an event handler.
+   *
+   * @param {String} event The name of the event.
+   * @param {function} handler The function that handles the event.
+   */
+  off(event, handler) {
+    const handlers = this.getHandlers(event);
+    const index = handlers.indexOf(handler);
+
+    if (index !== -1) {
+      handlers.splice(index, 1);
+    }
+  }
+}

js/src/common/utils/extract.js

@@ -0,0 +1,15 @@
+/**
+ * The `extract` utility deletes a property from an object and returns its
+ * value.
+ *
+ * @param {Object} object The object that owns the property
+ * @param {String} property The name of the property to extract
+ * @return {*} The value of the property
+ */
+export default function extract(object, property) {
+  const value = object[property];
+
+  delete object[property];
+
+  return value;
+}

js/src/common/utils/extractText.js

@@ -0,0 +1,15 @@
+/**
+ * Extract the text nodes from a virtual element.
+ *
+ * @param {VirtualElement} vdom
+ * @return {String}
+ */
+export default function extractText(vdom) {
+  if (vdom instanceof Array) {
+    return vdom.map(element => extractText(element)).join('');
+  } else if (typeof vdom === 'object' && vdom !== null) {
+    return extractText(vdom.children);
+  } else {
+    return vdom;
+  }
+}

js/src/common/utils/formatNumber.js

@@ -0,0 +1,14 @@
+/**
+ * The `formatNumber` utility localizes a number into a string with the
+ * appropriate punctuation.
+ *
+ * @example
+ * formatNumber(1234);
+ * // 1,234
+ *
+ * @param {Number} number
+ * @return {String}
+ */
+export default function formatNumber(number) {
+  return number.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ',');
+}

js/src/common/utils/humanTime.js

@@ -0,0 +1,36 @@
+/**
+ * The `humanTime` utility converts a date to a localized, human-readable time-
+ * ago string.
+ *
+ * @param {Date} time
+ * @return {String}
+ */
+export default function humanTime(time) {
+  let m = moment(time);
+  const now = moment();
+
+  // To prevent showing things like "in a few seconds" due to small offsets
+  // between client and server time, we always reset future dates to the
+  // current time. This will result in "just now" being shown instead.
+  if (m.isAfter(now)) {
+    m = now;
+  }
+
+  const day = 864e5;
+  const diff = m.diff(moment());
+  let ago = null;
+
+  // If this date was more than a month ago, we'll show the name of the month
+  // in the string. If it wasn't this year, we'll show the year as well.
+  if (diff < -30 * day) {
+    if (m.year() === moment().year()) {
+      ago = m.format('D MMM');
+    } else {
+      ago = m.format('MMM \'YY');
+    }
+  } else {
+    ago = m.fromNow();
+  }
+
+  return ago;
+};

js/src/common/utils/liveHumanTimes.js

@@ -0,0 +1,18 @@
+import humanTimeUtil from './humanTime';
+
+function updateHumanTimes() {
+  $('[data-humantime]').each(function() {
+    const $this = $(this);
+    const ago = humanTimeUtil($this.attr('datetime'));
+
+    $this.html(ago);
+  });
+}
+
+/**
+ * The `humanTime` initializer sets up a loop every 1 second to update
+ * timestamps rendered with the `humanTime` helper.
+ */
+export default function humanTime() {
+  setInterval(updateHumanTimes, 10000);
+}

js/src/common/utils/mapRoutes.js

@@ -0,0 +1,22 @@
+/**
+ * The `mapRoutes` utility converts a map of named application routes into a
+ * format that can be understood by Mithril.
+ *
+ * @see https://lhorie.github.io/mithril/mithril.route.html#defining-routes
+ * @param {Object} routes
+ * @param {String} [basePath]
+ * @return {Object}
+ */
+export default function mapRoutes(routes, basePath = '') {
+  const map = {};
+
+  for (const key in routes) {
+    const route = routes[key];
+
+    if (route.component) route.component.props.routeName = key;
+
+    map[basePath + route.path] = route.component;
+  }
+
+  return map;
+}

js/src/common/utils/mixin.js

@@ -0,0 +1,20 @@
+/**
+ * The `mixin` utility assigns the properties of a set of 'mixin' objects to
+ * the prototype of a parent object.
+ *
+ * @example
+ * class MyClass extends mixin(ExistingClass, evented, etc) {}
+ *
+ * @param {Class} Parent The class to extend the new class from.
+ * @param {...Object} mixins The objects to mix in.
+ * @return {Class} A new class that extends Parent and contains the mixins.
+ */
+export default function mixin(Parent, ...mixins) {
+  class Mixed extends Parent {}
+
+  mixins.forEach(object => {
+    Object.assign(Mixed.prototype, object);
+  });
+
+  return Mixed;
+}

js/src/common/utils/patchMithril.js

@@ -0,0 +1,45 @@
+import Component from '../Component';
+
+export default function patchMithril(global) {
+  const mo = global.m;
+
+  const m = function(comp, ...args) {
+    if (comp.prototype && comp.prototype instanceof Component) {
+      let children = args.slice(1);
+      if (children.length === 1 && Array.isArray(children[0])) {
+        children = children[0]
+      }
+
+      return comp.component(args[0], children);
+    }
+
+    const node = mo.apply(this, arguments);
+
+    if (node.attrs.bidi) {
+      m.bidi(node, node.attrs.bidi);
+    }
+
+    if (node.attrs.route) {
+      node.attrs.href = node.attrs.route;
+      node.attrs.config = m.route;
+
+      delete node.attrs.route;
+    }
+
+    return node;
+  };
+
+  Object.keys(mo).forEach(key => m[key] = mo[key]);
+
+  /**
+   * Redraw only if not in the middle of a computation (e.g. a route change).
+   *
+   * @return {void}
+   */
+  m.lazyRedraw = function() {
+    m.startComputation();
+    m.endComputation();
+  };
+
+  global.m = m;
+}

js/src/common/utils/string.js

@@ -0,0 +1,63 @@
+/**
+ * Truncate a string to the given length, appending ellipses if necessary.
+ *
+ * @param {String} string
+ * @param {Number} length
+ * @param {Number} [start=0]
+ * @return {String}
+ */
+export function truncate(string, length, start = 0) {
+  return (start > 0 ? '...' : '') +
+    string.substring(start, start + length) +
+    (string.length > start + length ? '...' : '');
+}
+
+/**
+ * Create a slug out of the given string. Non-alphanumeric characters are
+ * converted to hyphens.
+ *
+ * @param {String} string
+ * @return {String}
+ */
+export function slug(string) {
+  return string.toLowerCase()
+    .replace(/[^a-z0-9]/gi, '-')
+    .replace(/-+/g, '-')
+    .replace(/-$|^-/g, '');
+}
+
+/**
+ * Strip HTML tags and quotes out of the given string, replacing them with
+ * meaningful punctuation.
+ *
+ * @param {String} string
+ * @return {String}
+ */
+export function getPlainContent(string) {
+  const html = string
+    .replace(/(<\/p>|<br>)/g, '$1 &nbsp;')
+    .replace(/<img\b[^>]*>/ig, ' ');
+
+  const dom = $('<div/>').html(html);
+
+  dom.find(getPlainContent.removeSelectors.join(',')).remove();
+
+  return dom.text().replace(/\s+/g, ' ').trim();
+}
+
+/**
+ * An array of DOM selectors to remove when getting plain content.
+ *
+ * @type {Array}
+ */
+getPlainContent.removeSelectors = ['blockquote', 'script'];
+
+/**
+ * Make a string's first character uppercase.
+ *
+ * @param {String} string
+ * @return {String}
+ */
+export function ucfirst(string) {
+  return string.substr(0, 1).toUpperCase() + string.substr(1);
+}

js/src/common/utils/stringToColor.js

@@ -0,0 +1,49 @@
+function hsvToRgb(h, s, v) {
+  let r;
+  let g;
+  let b;
+
+  const i = Math.floor(h * 6);
+  const f = h * 6 - i;
+  const p = v * (1 - s);
+  const q = v * (1 - f * s);
+  const t = v * (1 - (1 - f) * s);
+
+  switch (i % 6) {
+    case 0: r = v; g = t; b = p; break;
+    case 1: r = q; g = v; b = p; break;
+    case 2: r = p; g = v; b = t; break;
+    case 3: r = p; g = q; b = v; break;
+    case 4: r = t; g = p; b = v; break;
+    case 5: r = v; g = p; b = q; break;
+  }
+
+  return {
+    r: Math.floor(r * 255),
+    g: Math.floor(g * 255),
+    b: Math.floor(b * 255)
+  };
+}
+
+/**
+ * Convert the given string to a unique color.
+ *
+ * @param {String} string
+ * @return {String}
+ */
+export default function stringToColor(string) {
+  let num = 0;
+
+  // Convert the username into a number based on the ASCII value of each
+  // character.
+  for (let i = 0; i < string.length; i++) {
+    num += string.charCodeAt(i);
+  }
+
+  // Construct a color using the remainder of that number divided by 360, and
+  // some predefined saturation and value values.
+  const hue = num % 360;
+  const rgb = hsvToRgb(hue / 360, 0.3, 0.9);
+
+  return '' + rgb.r.toString(16) + rgb.g.toString(16) + rgb.b.toString(16);
+}

js/src/forum/ForumApplication.js

@@ -0,0 +1,167 @@
+import History from './utils/History';
+import Pane from './utils/Pane';
+import Search from './components/Search';
+import ReplyComposer from './components/ReplyComposer';
+import DiscussionPage from './components/DiscussionPage';
+import SignUpModal from './components/SignUpModal';
+import HeaderPrimary from './components/HeaderPrimary';
+import HeaderSecondary from './components/HeaderSecondary';
+import Composer from './components/Composer';
+import DiscussionRenamedNotification from './components/DiscussionRenamedNotification';
+import CommentPost from './components/CommentPost';
+import DiscussionRenamedPost from './components/DiscussionRenamedPost';
+import routes from './routes';
+import alertEmailConfirmation from './utils/alertEmailConfirmation';
+import Application from '../common/Application';
+import Navigation from '../common/components/Navigation';
+
+export default class ForumApplication extends Application {
+  /**
+   * A map of notification types to their components.
+   *
+   * @type {Object}
+   */
+  notificationComponents = {
+    discussionRenamed: DiscussionRenamedNotification
+  };
+  /**
+   * A map of post types to their components.
+   *
+   * @type {Object}
+   */
+  postComponents = {
+    comment: CommentPost,
+    discussionRenamed: DiscussionRenamedPost
+  };
+
+  /**
+   * The page's search component instance.
+   *
+   * @type {SearchBox}
+   */
+  search = new Search();
+
+  /**
+   * An object which controls the state of the page's side pane.
+   *
+   * @type {Pane}
+   */
+  pane = null;
+
+  /**
+   * An object which controls the state of the page's drawer.
+   *
+   * @type {Drawer}
+   */
+  drawer = null;
+
+  /**
+   * The app's history stack, which keeps track of which routes the user visits
+   * so that they can easily navigate back to the previous route.
+   *
+   * @type {History}
+   */
+  history = new History();
+
+  /**
+   * @inheritdoc
+   */
+  boot(data) {
+    routes(this);
+
+    super.boot(data);
+  }
+
+  /**
+   * @inheritdoc
+   */
+  mount() {
+    // Get the configured default route and update that route's path to be '/'.
+    // Push the homepage as the first route, so that the user will always be
+    // able to click on the 'back' button to go home, regardless of which page
+    // they started on.
+    const defaultRoute = this.forum.attribute('defaultRoute');
+    let defaultAction = 'index';
+
+    for (const i in this.routes) {
+      if (this.routes[i].path === defaultRoute) defaultAction = i;
+    }
+
+    this.routes[defaultAction].path = '/';
+    this.history.push(defaultAction, this.translator.trans('core.forum.header.back_to_index_tooltip'), '/');
+
+    m.mount(document.getElementById('app-navigation'), Navigation.component({className: 'App-backControl', drawer: true}));
+    m.mount(document.getElementById('header-navigation'), Navigation.component());
+    m.mount(document.getElementById('header-primary'), HeaderPrimary.component());
+    m.mount(document.getElementById('header-secondary'), HeaderSecondary.component());
+
+    this.pane = new Pane(document.getElementById('app'));
+    this.composer = m.mount(document.getElementById('composer'), Composer.component());
+
+    m.route.mode = 'pathname';
+    super.mount();
+
+    alertEmailConfirmation(this);
+
+    // Route the home link back home when clicked. We do not want it to register
+    // if the user is opening it in a new tab, however.
+    $('#home-link').click(e => {
+      if (e.ctrlKey || e.metaKey || e.which === 2) return;
+      e.preventDefault();
+      app.history.home();
+
+      // Reload the current user so that their unread notification count is refreshed.
+      if (app.session.user) {
+        app.store.find('users', app.session.user.id());
+        m.redraw();
+      }
+    });
+  }
+
+  /**
+   * Check whether or not the user is currently composing a reply to a
+   * discussion.
+   *
+   * @param {Discussion} discussion
+   * @return {Boolean}
+   */
+  composingReplyTo(discussion) {
+    return this.composer.component instanceof ReplyComposer &&
+      this.composer.component.props.discussion === discussion &&
+      this.composer.position !== Composer.PositionEnum.HIDDEN;
+  }
+
+  /**
+   * Check whether or not the user is currently viewing a discussion.
+   *
+   * @param {Discussion} discussion
+   * @return {Boolean}
+   */
+  viewingDiscussion(discussion) {
+    return this.current instanceof DiscussionPage &&
+      this.current.discussion === discussion;
+  }
+
+  /**
+   * Callback for when an external authenticator (social login) action has
+   * completed.
+   *
+   * If the payload indicates that the user has been logged in, then the page
+   * will be reloaded. Otherwise, a SignUpModal will be opened, prefilled
+   * with the provided details.
+   *
+   * @param {Object} payload A dictionary of props to pass into the sign up
+   *     modal. A truthy `authenticated` prop indicates that the user has logged
+   *     in, and thus the page is reloaded.
+   * @public
+   */
+  authenticationComplete(payload) {
+    if (payload.authenticated) {
+      window.location.reload();
+    } else {
+      const modal = new SignUpModal(payload);
+      this.modal.show(modal);
+      modal.$('[name=password]').focus();
+    }
+  }
+}

js/src/forum/compat.js

@@ -0,0 +1,137 @@
+import compat from '../common/compat';
+
+import PostControls from './utils/PostControls';
+import KeyboardNavigatable from './utils/KeyboardNavigatable';
+import slidable from './utils/slidable';
+import affixSidebar from './utils/affixSidebar';
+import History from './utils/History';
+import DiscussionControls from './utils/DiscussionControls';
+import alertEmailConfirmation from './utils/alertEmailConfirmation';
+import UserControls from './utils/UserControls';
+import Pane from './utils/Pane';
+import DiscussionPage from './components/DiscussionPage';
+import LogInModal from './components/LogInModal';
+import ComposerBody from './components/ComposerBody';
+import ForgotPasswordModal from './components/ForgotPasswordModal';
+import Notification from './components/Notification';
+import LogInButton from './components/LogInButton';
+import DiscussionsUserPage from './components/DiscussionsUserPage';
+import Composer from './components/Composer';
+import SessionDropdown from './components/SessionDropdown';
+import HeaderPrimary from './components/HeaderPrimary';
+import PostEdited from './components/PostEdited';
+import PostStream from './components/PostStream';
+import ChangePasswordModal from './components/ChangePasswordModal';
+import IndexPage from './components/IndexPage';
+import Page from './components/Page';
+import DiscussionRenamedNotification from './components/DiscussionRenamedNotification';
+import DiscussionsSearchSource from './components/DiscussionsSearchSource';
+import HeaderSecondary from './components/HeaderSecondary';
+import ComposerButton from './components/ComposerButton';
+import DiscussionList from './components/DiscussionList';
+import ReplyPlaceholder from './components/ReplyPlaceholder';
+import TextEditor from './components/TextEditor';
+import AvatarEditor from './components/AvatarEditor';
+import Post from './components/Post';
+import SettingsPage from './components/SettingsPage';
+import TerminalPost from './components/TerminalPost';
+import ChangeEmailModal from './components/ChangeEmailModal';
+import NotificationsDropdown from './components/NotificationsDropdown';
+import UserPage from './components/UserPage';
+import PostUser from './components/PostUser';
+import UserCard from './components/UserCard';
+import UsersSearchSource from './components/UsersSearchSource';
+import NotificationGrid from './components/NotificationGrid';
+import PostPreview from './components/PostPreview';
+import EventPost from './components/EventPost';
+import DiscussionHero from './components/DiscussionHero';
+import PostMeta from './components/PostMeta';
+import EditUserModal from './components/EditUserModal';
+import SearchSource from './components/SearchSource';
+import DiscussionRenamedPost from './components/DiscussionRenamedPost';
+import DiscussionComposer from './components/DiscussionComposer';
+import LogInButtons from './components/LogInButtons';
+import NotificationList from './components/NotificationList';
+import WelcomeHero from './components/WelcomeHero';
+import SignUpModal from './components/SignUpModal';
+import CommentPost from './components/CommentPost';
+import ReplyComposer from './components/ReplyComposer';
+import NotificationsPage from './components/NotificationsPage';
+import PostStreamScrubber from './components/PostStreamScrubber';
+import EditPostComposer from './components/EditPostComposer';
+import RenameDiscussionModal from './components/RenameDiscussionModal';
+import Search from './components/Search';
+import DiscussionListItem from './components/DiscussionListItem';
+import LoadingPost from './components/LoadingPost';
+import PostsUserPage from './components/PostsUserPage';
+import routes from './routes';
+import ForumApplication from './ForumApplication';
+
+export default Object.assign(compat, {
+  'utils/PostControls': PostControls,
+  'utils/KeyboardNavigatable': KeyboardNavigatable,
+  'utils/slidable': slidable,
+  'utils/affixSidebar': affixSidebar,
+  'utils/History': History,
+  'utils/DiscussionControls': DiscussionControls,
+  'utils/alertEmailConfirmation': alertEmailConfirmation,
+  'utils/UserControls': UserControls,
+  'utils/Pane': Pane,
+  'components/DiscussionPage': DiscussionPage,
+  'components/LogInModal': LogInModal,
+  'components/ComposerBody': ComposerBody,
+  'components/ForgotPasswordModal': ForgotPasswordModal,
+  'components/Notification': Notification,
+  'components/LogInButton': LogInButton,
+  'components/DiscussionsUserPage': DiscussionsUserPage,
+  'components/Composer': Composer,
+  'components/SessionDropdown': SessionDropdown,
+  'components/HeaderPrimary': HeaderPrimary,
+  'components/PostEdited': PostEdited,
+  'components/PostStream': PostStream,
+  'components/ChangePasswordModal': ChangePasswordModal,
+  'components/IndexPage': IndexPage,
+  'components/Page': Page,
+  'components/DiscussionRenamedNotification': DiscussionRenamedNotification,
+  'components/DiscussionsSearchSource': DiscussionsSearchSource,
+  'components/HeaderSecondary': HeaderSecondary,
+  'components/ComposerButton': ComposerButton,
+  'components/DiscussionList': DiscussionList,
+  'components/ReplyPlaceholder': ReplyPlaceholder,
+  'components/TextEditor': TextEditor,
+  'components/AvatarEditor': AvatarEditor,
+  'components/Post': Post,
+  'components/SettingsPage': SettingsPage,
+  'components/TerminalPost': TerminalPost,
+  'components/ChangeEmailModal': ChangeEmailModal,
+  'components/NotificationsDropdown': NotificationsDropdown,
+  'components/UserPage': UserPage,
+  'components/PostUser': PostUser,
+  'components/UserCard': UserCard,
+  'components/UsersSearchSource': UsersSearchSource,
+  'components/NotificationGrid': NotificationGrid,
+  'components/PostPreview': PostPreview,
+  'components/EventPost': EventPost,
+  'components/DiscussionHero': DiscussionHero,
+  'components/PostMeta': PostMeta,
+  'components/EditUserModal': EditUserModal,
+  'components/SearchSource': SearchSource,
+  'components/DiscussionRenamedPost': DiscussionRenamedPost,
+  'components/DiscussionComposer': DiscussionComposer,
+  'components/LogInButtons': LogInButtons,
+  'components/NotificationList': NotificationList,
+  'components/WelcomeHero': WelcomeHero,
+  'components/SignUpModal': SignUpModal,
+  'components/CommentPost': CommentPost,
+  'components/ReplyComposer': ReplyComposer,
+  'components/NotificationsPage': NotificationsPage,
+  'components/PostStreamScrubber': PostStreamScrubber,
+  'components/EditPostComposer': EditPostComposer,
+  'components/RenameDiscussionModal': RenameDiscussionModal,
+  'components/Search': Search,
+  'components/DiscussionListItem': DiscussionListItem,
+  'components/LoadingPost': LoadingPost,
+  'components/PostsUserPage': PostsUserPage,
+  'routes': routes,
+  'ForumApplication': ForumApplication
+});

js/src/forum/components/AvatarEditor.js

@@ -0,0 +1,227 @@
+import Component from '../../common/Component';
+import avatar from '../../common/helpers/avatar';
+import icon from '../../common/helpers/icon';
+import listItems from '../../common/helpers/listItems';
+import ItemList from '../../common/utils/ItemList';
+import Button from '../../common/components/Button';
+import LoadingIndicator from '../../common/components/LoadingIndicator';
+
+/**
+ * The `AvatarEditor` component displays a user's avatar along with a dropdown
+ * menu which allows the user to upload/remove the avatar.
+ *
+ * ### Props
+ *
+ * - `className`
+ * - `user`
+ */
+export default class AvatarEditor extends Component {
+  init() {
+    /**
+     * Whether or not an avatar upload is in progress.
+     *
+     * @type {Boolean}
+     */
+    this.loading = false;
+
+    /**
+     * Whether or not an image has been dragged over the dropzone.
+     *
+     * @type {Boolean}
+     */
+    this.isDraggedOver = false;
+  }
+
+  static initProps(props) {
+    super.initProps(props);
+
+    props.className = props.className || '';
+  }
+
+  view() {
+    const user = this.props.user;
+
+    return (
+      <div className={'AvatarEditor Dropdown ' + this.props.className + (this.loading ? ' loading' : '') + (this.isDraggedOver ? ' dragover' : '')}>
+        {avatar(user)}
+        <a className={ user.avatarUrl() ? "Dropdown-toggle" : "Dropdown-toggle AvatarEditor--noAvatar" }
+          title={app.translator.trans('core.forum.user.avatar_upload_tooltip')}
+          data-toggle="dropdown"
+          onclick={this.quickUpload.bind(this)}
+          ondragover={this.enableDragover.bind(this)}
+          ondragenter={this.enableDragover.bind(this)}
+          ondragleave={this.disableDragover.bind(this)}
+          ondragend={this.disableDragover.bind(this)}
+          ondrop={this.dropUpload.bind(this)}>
+          {this.loading ? LoadingIndicator.component() : (user.avatarUrl() ? icon('fas fa-pencil-alt') : icon('fas fa-plus-circle'))}
+        </a>
+        <ul className="Dropdown-menu Menu">
+          {listItems(this.controlItems().toArray())}
+        </ul>
+      </div>
+    );
+  }
+
+  /**
+   * Get the items in the edit avatar dropdown menu.
+   *
+   * @return {ItemList}
+   */
+  controlItems() {
+    const items = new ItemList();
+
+    items.add('upload',
+      Button.component({
+        icon: 'fas fa-upload',
+        children: app.translator.trans('core.forum.user.avatar_upload_button'),
+        onclick: this.openPicker.bind(this)
+      })
+    );
+
+    items.add('remove',
+      Button.component({
+        icon: 'fas fa-times',
+        children: app.translator.trans('core.forum.user.avatar_remove_button'),
+        onclick: this.remove.bind(this)
+      })
+    );
+
+    return items;
+  }
+
+  /**
+   * Enable dragover style
+   *
+   * @param {Event} e
+   */
+  enableDragover(e) {
+    e.preventDefault();
+    e.stopPropagation();
+    this.isDraggedOver = true;
+  }
+
+  /**
+   * Disable dragover style
+   *
+   * @param {Event} e
+   */
+  disableDragover(e) {
+    e.preventDefault();
+    e.stopPropagation();
+    this.isDraggedOver = false;
+  }
+
+  /**
+   * Upload avatar when file is dropped into dropzone.
+   *
+   * @param {Event} e
+   */
+  dropUpload(e) {
+    e.preventDefault();
+    e.stopPropagation();
+    this.isDraggedOver = false;
+    this.upload(e.dataTransfer.files[0]);
+  }
+
+  /**
+   * If the user doesn't have an avatar, there's no point in showing the
+   * controls dropdown, because only one option would be viable: uploading.
+   * Thus, when the avatar editor's dropdown toggle button is clicked, we prompt
+   * the user to upload an avatar immediately.
+   *
+   * @param {Event} e
+   */
+  quickUpload(e) {
+    if (!this.props.user.avatarUrl()) {
+      e.preventDefault();
+      e.stopPropagation();
+      this.openPicker();
+    }
+  }
+
+  /**
+   * Upload avatar using file picker
+   */
+  openPicker() {
+    if (this.loading) return;
+
+    // Create a hidden HTML input element and click on it so the user can select
+    // an avatar file. Once they have, we will upload it via the API.
+    const user = this.props.user;
+    const $input = $('<input type="file">');
+
+    $input.appendTo('body').hide().click().on('change', e => {
+      this.upload($(e.target)[0].files[0]);
+    });
+  }
+
+  /**
+   * Upload avatar
+   *
+   * @param {File} file
+   */
+  upload(file) {
+    if (this.loading) return;
+
+    const user = this.props.user;
+    const data = new FormData();
+    data.append('avatar', file);
+
+    this.loading = true;
+    m.redraw();
+
+    app.request({
+      method: 'POST',
+      url: app.forum.attribute('apiUrl') + '/users/' + user.id() + '/avatar',
+      serialize: raw => raw,
+      data
+    }).then(
+      this.success.bind(this),
+      this.failure.bind(this)
+    );
+  }
+
+  /**
+   * Remove the user's avatar.
+   */
+  remove() {
+    const user = this.props.user;
+
+    this.loading = true;
+    m.redraw();
+
+    app.request({
+      method: 'DELETE',
+      url: app.forum.attribute('apiUrl') + '/users/' + user.id() + '/avatar'
+    }).then(
+      this.success.bind(this),
+      this.failure.bind(this)
+    );
+  }
+
+  /**
+   * After a successful upload/removal, push the updated user data into the
+   * store, and force a recomputation of the user's avatar color.
+   *
+   * @param {Object} response
+   * @protected
+   */
+  success(response) {
+    app.store.pushPayload(response);
+    delete this.props.user.avatarColor;
+
+    this.loading = false;
+    m.redraw();
+  }
+
+  /**
+   * If avatar upload/removal fails, stop loading.
+   *
+   * @param {Object} response
+   * @protected
+   */
+  failure(response) {
+    this.loading = false;
+    m.redraw();
+  }
+}

js/src/forum/components/ChangeEmailModal.js

@@ -0,0 +1,116 @@
+import Modal from '../../common/components/Modal';
+import Button from '../../common/components/Button';
+
+/**
+ * The `ChangeEmailModal` component shows a modal dialog which allows the user
+ * to change their email address.
+ */
+export default class ChangeEmailModal extends Modal {
+  init() {
+    super.init();
+
+    /**
+     * Whether or not the email has been changed successfully.
+     *
+     * @type {Boolean}
+     */
+    this.success = false;
+
+    /**
+     * The value of the email input.
+     *
+     * @type {function}
+     */
+    this.email = m.prop(app.session.user.email());
+
+    /**
+     * The value of the password input.
+     *
+     * @type {function}
+     */
+    this.password = m.prop('');
+  }
+
+  className() {
+    return 'ChangeEmailModal Modal--small';
+  }
+
+  title() {
+    return app.translator.trans('core.forum.change_email.title');
+  }
+
+  content() {
+    if (this.success) {
+      return (
+        <div className="Modal-body">
+          <div className="Form Form--centered">
+            <p className="helpText">{app.translator.trans('core.forum.change_email.confirmation_message', {email: <strong>{this.email()}</strong>})}</p>
+            <div className="Form-group">
+              <Button className="Button Button--primary Button--block" onclick={this.hide.bind(this)}>
+                {app.translator.trans('core.forum.change_email.dismiss_button')}
+              </Button>
+            </div>
+          </div>
+        </div>
+      );
+    }
+
+    return (
+      <div className="Modal-body">
+        <div className="Form Form--centered">
+          <div className="Form-group">
+            <input type="email" name="email" className="FormControl"
+              placeholder={app.session.user.email()}
+              bidi={this.email}
+              disabled={this.loading}/>
+          </div>
+          <div className="Form-group">
+            <input type="password" name="password" className="FormControl"
+              placeholder={app.translator.trans('core.forum.change_email.confirm_password_placeholder')}
+              bidi={this.password}
+              disabled={this.loading}/>
+          </div>
+          <div className="Form-group">
+            {Button.component({
+              className: 'Button Button--primary Button--block',
+              type: 'submit',
+              loading: this.loading,
+              children: app.translator.trans('core.forum.change_email.submit_button')
+            })}
+          </div>
+        </div>
+      </div>
+    );
+  }
+
+  onsubmit(e) {
+    e.preventDefault();
+
+    // If the user hasn't actually entered a different email address, we don't
+    // need to do anything. Woot!
+    if (this.email() === app.session.user.email()) {
+      this.hide();
+      return;
+    }
+
+    const oldEmail = app.session.user.email();
+
+    this.loading = true;
+
+    app.session.user.save({email: this.email()}, {
+      errorHandler: this.onerror.bind(this),
+      meta: {password: this.password()}
+    })
+      .then(() => this.success = true)
+      .catch(() => {})
+      .then(this.loaded.bind(this));
+  }
+
+  onerror(error) {
+    if (error.status === 401) {
+      error.alert.props.children = app.translator.trans('core.forum.change_email.incorrect_password_message');
+    }
+
+    super.onerror(error);
+  }
+}

js/src/forum/components/ChangePasswordModal.js

@@ -0,0 +1,49 @@
+import Modal from '../../common/components/Modal';
+import Button from '../../common/components/Button';
+
+/**
+ * The `ChangePasswordModal` component shows a modal dialog which allows the
+ * user to send themself a password reset email.
+ */
+export default class ChangePasswordModal extends Modal {
+  className() {
+    return 'ChangePasswordModal Modal--small';
+  }
+
+  title() {
+    return app.translator.trans('core.forum.change_password.title');
+  }
+
+  content() {
+    return (
+      <div className="Modal-body">
+        <div className="Form Form--centered">
+          <p className="helpText">{app.translator.trans('core.forum.change_password.text')}</p>
+          <div className="Form-group">
+            {Button.component({
+              className: 'Button Button--primary Button--block',
+              type: 'submit',
+              loading: this.loading,
+              children: app.translator.trans('core.forum.change_password.send_button')
+            })}
+          </div>
+        </div>
+      </div>
+    );
+  }
+
+  onsubmit(e) {
+    e.preventDefault();
+
+    this.loading = true;
+
+    app.request({
+      method: 'POST',
+      url: app.forum.attribute('apiUrl') + '/forgot',
+      data: {email: app.session.user.email()}
+    }).then(
+      this.hide.bind(this),
+      this.loaded.bind(this)
+    );
+  }
+}