Massive JavaScript cleanup

- Use JSX for templates
- Docblock/comment everything
- Mostly passes ESLint (still some work to do)
- Lots of renaming, refactoring, etc.

CSS hasn't been updated yet.

js/forum/src/components/ActivityPage.js

@@ -0,0 +1,140 @@
+import UserPage from 'flarum/components/UserPage';
+import LoadingIndicator from 'flarum/components/LoadingIndicator';
+import Button from 'flarum/components/Button';
+
+/**
+ * The `ActivityPage` component shows a user's activity feed inside of their
+ * profile.
+ */
+export default class ActivityPage extends UserPage {
+  constructor(...args) {
+    super(...args);
+
+    /**
+     * Whether or not the activity feed is currently loading.
+     *
+     * @type {Boolean}
+     */
+    this.loading = true;
+
+    /**
+     * Whether or not there are any more activity items that can be loaded.
+     *
+     * @type {Boolean}
+     */
+    this.moreResults = false;
+
+    /**
+     * The Activity models in the feed.
+     * @type {Activity[]}
+     */
+    this.activity = [];
+
+    /**
+     * The number of activity items to load per request.
+     *
+     * @type {Integer}
+     */
+    this.loadLimit = 20;
+
+    this.loadUser(m.route.param('username'));
+  }
+
+  content() {
+    let footer;
+
+    if (this.loading) {
+      footer = LoadingIndicator.component();
+    } else if (this.moreResults) {
+      footer = (
+        <div className="load-more">
+          {Button.component({
+            children: 'Load More',
+            className: 'btn btn-default',
+            onclick: this.loadMore.bind(this)
+          })}
+        </div>
+      );
+    }
+
+    return (
+      <div className="user-activity">
+        <ul className="activity-list">
+          {this.activity.map(activity => {
+            const ActivityComponent = app.activityComponents[activity.contentType()];
+            return ActivityComponent ? <li>{ActivityComponent.component({activity})}</li> : '';
+          })}
+        </ul>
+        {footer}
+      </div>
+    );
+  }
+
+  /**
+   * Initialize the component with a user, and trigger the loading of their
+   * activity feed.
+   */
+  init(user) {
+    super.init(user);
+
+    this.refresh();
+  }
+
+  /**
+   * Clear and reload the user's activity feed.
+   *
+   * @public
+   */
+  refresh() {
+    this.loading = true;
+    this.activity = [];
+
+    m.redraw();
+
+    this.loadResults().then(this.parseResults.bind(this));
+  }
+
+  /**
+   * Load a new page of the user's activity feed.
+   *
+   * @param {Integer} [offset] The position to start getting results from.
+   * @return {Promise}
+   * @protected
+   */
+  loadResults(offset) {
+    return app.store.find('activity', {
+      filter: {
+        user: this.user.id(),
+        type: this.props.filter
+      },
+      page: {offset, limit: this.loadLimit}
+    });
+  }
+
+  /**
+   * Load the next page of results.
+   *
+   * @public
+   */
+  loadMore() {
+    this.loading = true;
+    this.loadResults(this.activity.length).then(this.parseResults.bind(this));
+  }
+
+  /**
+   * Parse results and append them to the activity feed.
+   *
+   * @param {Activity[]} results
+   * @return {Activity[]}
+   */
+  parseResults(results) {
+    this.loading = false;
+
+    [].push.apply(this.activity, results);
+
+    this.moreResults = results.length >= this.loadLimit;
+    m.redraw();
+
+    return results;
+  }
+}