Fix lifecyle method workarounds (#2378)

Essentially, whenever a route is loaded, we add a key to that component. If the key changes, the page completely rerenders. Switching between different routes handled by the same key triggers those rerenders.

js/src/forum/components/DiscussionPage.js

@@ -47,8 +47,6 @@ export default class DiscussionPage extends Page {
     app.history.push('discussion');
 
     this.bodyClass = 'App--discussion';
-
-    this.prevRoute = m.route.get();
   }
 
   onremove() {
@@ -96,34 +94,6 @@ export default class DiscussionPage extends Page {
     );
   }
 
-  onbeforeupdate(vnode) {
-    super.onbeforeupdate(vnode);
-
-    if (m.route.get() !== this.prevRoute) {
-      this.prevRoute = m.route.get();
-
-      // If we have routed to the same discussion as we were viewing previously,
-      // cancel the unloading of this controller and instead prompt the post
-      // stream to jump to the new 'near' param.
-      if (this.discussion) {
-        const idParam = m.route.param('id');
-
-        if (idParam && idParam.split('-')[0] === this.discussion.id()) {
-          const near = m.route.param('near') || '1';
-
-          if (near !== String(this.near)) {
-            this.stream.goToNumber(near);
-          }
-
-          this.near = near;
-        } else {
-          this.onNewRoute();
-          this.oninit(vnode);
-        }
-      }
-    }
-  }
-
   /**
    * Load the discussion from the API or use the preloaded one.
    */
@@ -248,10 +218,7 @@ export default class DiscussionPage extends Page {
     // replace it into the window's history and our own history stack.
     const url = app.route.discussion(discussion, (this.near = startNumber));
 
-    this.prevRoute = url;
-    m.route.set(url, null, { replace: true });
     window.history.replaceState(null, document.title, url);
-
     app.history.push('discussion', discussion.title());
 
     // If the user hasn't read past here before, then we'll update their read

js/src/forum/components/IndexPage.js

@@ -42,26 +42,6 @@ export default class IndexPage extends Page {
     app.history.push('index', app.translator.trans('core.forum.header.back_to_index_tooltip'));
 
     this.bodyClass = 'App--index';
-
-    this.currentPath = m.route.get();
-  }
-
-  onbeforeupdate(vnode) {
-    super.onbeforeupdate(vnode);
-
-    const curPath = m.route.get();
-
-    if (this.currentPath !== curPath) {
-      this.onNewRoute();
-
-      app.discussions.clear();
-
-      app.discussions.refreshParams(app.search.params());
-
-      this.currentPath = curPath;
-
-      this.setTitle();
-    }
   }
 
   view() {

js/src/forum/components/UserPage.js

@@ -27,19 +27,6 @@ export default class UserPage extends Page {
     this.user = null;
 
     this.bodyClass = 'App--user';
-
-    this.prevUsername = m.route.param('username');
-  }
-
-  onbeforeupdate() {
-    const currUsername = m.route.param('username');
-    if (currUsername !== this.prevUsername) {
-      this.onNewRoute();
-
-      this.prevUsername = currUsername;
-
-      this.loadUser(currUsername);
-    }
   }
 
   view() {