Extract base Page class

js/forum/src/components/Page.js

@@ -0,0 +1,35 @@
+import Component from 'flarum/Component';
+
+/**
+ * The `Page` component
+ *
+ * @abstract
+ */
+export default class Page extends Component {
+  constructor(...args) {
+    super(...args);
+
+    app.previous = app.current;
+    app.current = this;
+
+    app.drawer.hide();
+    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);
+    }
+  }
+}