Improve post stream

- Return all discussion post IDs from API requests which add/remove
posts, so the post stream updates appropriately. Related to #146
- Always unload posts that are two pages away, no matter how fast
you’re scrolling
- Retrieve posts from cache instead of reloading them
- Fix various bugs. Maybe #152, needs confirmation

framework/core/js/forum/src/components/post-stream.js

@@ -69,43 +69,15 @@ class PostStream extends mixin(Component, evented) {
     return this.goToIndex(this.count() - 1, true);
   }
 
-  /**
-    Update the stream to reflect any posts that have been added/removed from the
-    discussion.
-   */
-  sync() {
-    var addedPosts = this.discussion.addedPosts();
-    if (addedPosts) addedPosts.forEach(this.pushPost.bind(this));
-    this.discussion.pushAttributes({links: {addedPosts: null}});
-
-    var removedPosts = this.discussion.removedPosts();
-    if (removedPosts) removedPosts.forEach(this.removePost.bind(this));
-    this.discussion.pushAttributes({removedPosts: null});
-  }
-
   /**
     Add a post to the end of the stream. Nothing will be done if the end of the
     stream is not visible.
    */
-  pushPost(post) {
-    if (this.visibleEnd >= this.count() - 1 && this.posts.indexOf(post) === -1) {
-      this.posts.push(post);
       this.visibleEnd++;
     }
   }
 
   /**
-    Search for and remove a specific post from the stream. Nothing will be done
-    if the post is not visible.
-   */
-  removePost(id) {
-    this.posts.some((item, i) => {
-      if (item && item.id() == id) {
-        this.posts.splice(i, 1);
-        this.visibleEnd--;
-        return true;
-      }
-    });
   }
 
   /**
@@ -127,7 +99,6 @@ class PostStream extends mixin(Component, evented) {
     Set up the stream with the given array of posts.
    */
   setup(posts) {
-    this.posts = posts;
     this.visibleStart = posts.length ? this.discussion.postIds().indexOf(posts[0].id()) : 0;
     this.visibleEnd = this.visibleStart + posts.length;
   }
@@ -137,11 +108,6 @@ class PostStream extends mixin(Component, evented) {
    */
   clear(start, end) {
     this.visibleStart = start || 0;
-    this.visibleEnd = Math.min(this.count(), end || this.constructor.loadCount);
-    this.posts = [];
-    for (var i = this.visibleStart; i < this.visibleEnd; i++) {
-      this.posts.push(null);
-    }
   }
 
   /**
@@ -157,7 +123,6 @@ class PostStream extends mixin(Component, evented) {
     var lastTime;
 
     return m('div.discussion-posts.posts', {config: this.onload.bind(this)},
-      this.posts.map((post, i) => {
         var content;
         var attributes = {};
         attributes['data-index'] = this.visibleStart + i;
@@ -172,7 +137,6 @@ class PostStream extends mixin(Component, evented) {
           attributes['data-number'] = post.number();
 
           var dt = post.time() - lastTime;
-          if (dt > 1000 * 60 * 60 * 24 * 4) {
             content = [
               m('div.time-gap', m('span', moment.duration(dt).humanize(), ' later')),
               content
@@ -193,7 +157,6 @@ class PostStream extends mixin(Component, evented) {
       this.visibleEnd === this.count() &&
         (!app.session.user() || this.discussion.canReply()) &&
         !app.composingReplyTo(this.discussion)
-        ? m('div.item', ReplyPlaceholder.component({discussion: this.discussion}))
         : ''
     );
   }
@@ -233,7 +196,6 @@ class PostStream extends mixin(Component, evented) {
     var marginTop = this.getMarginTop();
     var viewportHeight = $(window).height() - marginTop;
     var viewportTop = top + marginTop;
-    var loadAheadDistance = viewportHeight;
 
     if (this.visibleStart > 0) {
       var $item = this.$('.item[data-index='+this.visibleStart+']');
@@ -262,17 +224,7 @@ class PostStream extends mixin(Component, evented) {
     var start = this.visibleEnd;
     var end = this.visibleEnd = this.sanitizeIndex(this.visibleEnd + this.constructor.loadCount);
 
-    for (var i = start; i < end; i++) {
-      this.posts.push(null);
-    }
-
-    // If the posts which are two pages back from the page we're currently
-    // loading still haven't loaded, we can assume that the user is scrolling
-    // pretty fast. Thus, we will unload them.
     var twoPagesAway = start - this.constructor.loadCount * 2;
-    if (twoPagesAway >= 0 && !this.posts[twoPagesAway - this.visibleStart]) {
-      this.posts.splice(0, twoPagesAway + this.constructor.loadCount - this.visibleStart);
-      this.visibleStart = twoPagesAway + this.constructor.loadCount;
       clearTimeout(this.loadPageTimeouts[twoPagesAway]);
     }
 
@@ -286,16 +238,7 @@ class PostStream extends mixin(Component, evented) {
     var end = this.visibleStart;
     var start = this.visibleStart = this.sanitizeIndex(this.visibleStart - this.constructor.loadCount);
 
-    for (var i = start; i < end; i++) {
-      this.posts.unshift(null);
-    }
-
-    // If the posts which are two pages back from the page we're currently
-    // loading still haven't loaded, we can assume that the user is scrolling
-    // pretty fast. Thus, we will unload them.
     var twoPagesAway = start + this.constructor.loadCount * 2;
-    if (twoPagesAway <= this.count() && !this.posts[twoPagesAway - this.visibleStart]) {
-      this.posts.splice(twoPagesAway - this.visibleStart);
       this.visibleEnd = twoPagesAway;
       clearTimeout(this.loadPageTimeouts[twoPagesAway]);
     }
@@ -310,8 +253,6 @@ class PostStream extends mixin(Component, evented) {
     var redraw = () => {
       if (start < this.visibleStart || end > this.visibleEnd) return;
 
-      var anchorIndex = backwards && $(window).scrollTop() > 0 ? this.visibleEnd - 1 : this.visibleStart;
-      anchorScroll(this.$('.item[data-index='+anchorIndex+']'), () => m.redraw(true));
 
       this.unpause();
     };
@@ -332,10 +273,7 @@ class PostStream extends mixin(Component, evented) {
     clearing it.
    */
   loadRange(start, end) {
-    return app.store.find('posts', this.discussion.postIds().slice(start, end)).then(posts => {
-      if (start < this.visibleStart || end > this.visibleEnd) return;
 
-      this.posts.splice.apply(this.posts, [start - this.visibleStart, end - start].concat(posts));
     });
   }
 
@@ -345,7 +283,6 @@ class PostStream extends mixin(Component, evented) {
     resolved immediately.
    */
   loadNearNumber(number) {
-    if (this.posts.some(post => post.number() == number)) {
       return m.deferred().resolve().promise;
     }
 
@@ -372,9 +309,6 @@ class PostStream extends mixin(Component, evented) {
 
     this.clear(start, end);
 
-    var ids = this.discussion.postIds().slice(start, end);
-
-    return app.store.find('posts', ids).then(this.setup.bind(this));
   }
 
   /**
@@ -419,7 +353,6 @@ class PostStream extends mixin(Component, evented) {
     would consider a post to be the first one visible.
    */
   getMarginTop() {
-    return this.$() && $('.global-header').outerHeight() + parseInt(this.$().css('margin-top'));
   }
 
   /**

framework/core/js/forum/src/components/reply-composer.js

@@ -2,7 +2,6 @@ import ItemList from 'flarum/utils/item-list';
 import ComposerBody from 'flarum/components/composer-body';
 import Alert from 'flarum/components/alert';
 import ActionButton from 'flarum/components/action-button';
-import Composer from 'flarum/components/composer';
 import icon from 'flarum/helpers/icon';
 
 export default class ReplyComposer extends ComposerBody {
@@ -44,26 +43,11 @@ export default class ReplyComposer extends ComposerBody {
 
     var data = this.data();
 
-    app.store.createRecord('posts').save(data).then((post) => {
-      app.composer.hide();
-
-      discussion.pushAttributes({
-        relationships: {
-          lastUser: post.user(),
-          lastPost: post
-        },
-        lastTime: post.time(),
-        lastPostNumber: post.number(),
-        commentsCount: discussion.commentsCount() + 1,
-        readTime: post.time(),
-        readNumber: post.number()
-      });
-      discussion.data().relationships.posts.data.push({type: 'posts', id: post.id()});
-
+    app.store.createRecord('posts').save(data).then(post => {
       // If we're currently viewing the discussion which this reply was made
       // in, then we can add the post to the end of the post stream.
-      if (app.current && app.current.discussion && app.current.discussion().id() === discussion.id()) {
-        app.current.stream.pushPost(post);
+      if (app.viewingDiscussion(discussion)) {
+        app.current.stream.update();
         m.route(app.route('discussion.near', {
           id: discussion.id(),
           slug: discussion.slug(),
@@ -89,6 +73,8 @@ export default class ReplyComposer extends ComposerBody {
           })
         );
       }
+
+      app.composer.hide();
     }, errors => {
       this.loading(false);
       m.redraw();

framework/core/js/forum/src/initializers/discussion-controls.js

@@ -55,20 +55,21 @@ export default function(app) {
         app.history.back();
       }
     }
-  }
+  };
 
   Discussion.prototype.renameAction = function() {
-    var currentTitle = this.title();
-    var title = prompt('Enter a new title for this discussion:', currentTitle);
+    const currentTitle = this.title();
+    const title = prompt('Enter a new title for this discussion:', currentTitle);
+
     if (title && title !== currentTitle) {
-      this.save({title}).then(discussion => {
-        if (app.current instanceof DiscussionPage) {
-          app.current.stream.sync();
+      this.save({title}).then(() => {
+        if (app.viewingDiscussion(this)) {
+          app.current.stream.update();
         }
         m.redraw();
       });
     }
-  }
+  };
 
   Discussion.prototype.userControls = function(context) {
     var items = new ItemList();

framework/core/js/forum/src/initializers/post-controls.js

@@ -23,10 +23,7 @@ export default function(app) {
 
   function deleteAction() {
     this.delete();
-    // this.discussion().pushAttributes({removedPosts: [this.id()]});
-    if (app.current instanceof DiscussionPage) {
-      app.current.stream.removePost(this.id());
-    }
+    this.discussion().removePost(this.id());
   }
 
   Post.prototype.userControls = function(context) {

framework/core/js/lib/models/discussion.js

@@ -27,6 +27,20 @@ class Discussion extends Model {
     // }
   }
 
+  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;
+        }
+      });
+    }
+  }
+
   unreadCount() {
     var user = app.session.user();
     if (user && user.readTime() < this.lastTime()) {

framework/core/src/Api/Actions/Discussions/UpdateAction.php

@@ -85,6 +85,17 @@ class UpdateAction extends SerializeResourceAction
             $discussion = $state->discussion;
         }
 
+        if ($posts = $discussion->getModifiedPosts()) {
+            $discussion->posts_ids = $discussion->postsVisibleTo($actor)->orderBy('time')->lists('id');
+
+            $discussion->posts = array_filter($posts, function ($post) {
+                return $post->exists;
+            });
+
+            $request->include = array_merge($request->include, ['posts']);
+            $request->link = array_merge($request->include, ['posts', 'posts.discussion', 'posts.user']);
+        }
+
         return $discussion;
     }
 }

framework/core/src/Api/Actions/Posts/CreateAction.php

@@ -22,13 +22,14 @@ class CreateAction extends BaseCreateAction
      * @inheritdoc
      */
     public static $include = [
-        'user' => true
+        'user' => true,
+        'discussion' => true
     ];
 
     /**
      * @inheritdoc
      */
-    public static $link = [];
+    public static $link = ['discussion.posts'];
 
     /**
      * @inheritdoc
@@ -84,6 +85,9 @@ class CreateAction extends BaseCreateAction
             );
         }
 
+        $discussion = $post->discussion;
+        $discussion->posts_ids = $discussion->postsVisibleTo($actor)->orderBy('time')->lists('id');
+
         return $post;
     }
 }

framework/core/src/Core/Discussions/Discussion.php

@@ -46,6 +46,13 @@ class Discussion extends Model
         'last_post_number'   => 'integer'
     ];
 
+    /**
+     * An array of posts that have been modified during this request.
+     *
+     * @var array
+     */
+    protected $modifiedPosts = [];
+
     /**
      * The attributes that should be mutated to dates.
      *
@@ -140,7 +147,7 @@ class Discussion extends Model
     /**
      * Set the discussion's start post details.
      *
-     * @param \Flarum\Core\Posts\Post $post
+     * @param Post $post
      * @return $this
      */
     public function setStartPost(Post $post)
@@ -155,7 +162,7 @@ class Discussion extends Model
     /**
      * Set the discussion's last post details.
      *
-     * @param \Flarum\Core\Posts\Post $post
+     * @param Post $post
      * @return $this
      */
     public function setLastPost(Post $post)
@@ -214,16 +221,28 @@ class Discussion extends Model
      * DiscussionRenamedPost, and delete if the title has been reverted
      * completely.)
      *
-     * @param \Flarum\Core\Posts\Post $post The post to save.
-     * @return \Flarum\Core\Posts\Post The resulting post. It may or may not be
-     *     the same post as was originally intended to be saved. It also may not
-     *     exist, if the merge logic resulted in deletion.
+     * @param MergeablePost $post The post to save.
+     * @return Post The resulting post. It may or may not be the same post as
+     *     was originally intended to be saved. It also may not exist, if the
+     *     merge logic resulted in deletion.
      */
     public function mergePost(MergeablePost $post)
     {
         $lastPost = $this->posts()->latest('time')->first();
 
-        return $post->saveAfter($lastPost);
+        $post = $post->saveAfter($lastPost);
+
+        return $this->modifiedPosts[] = $post;
+    }
+
+    /**
+     * Get the posts that have been modified during this request.
+     *
+     * @return array
+     */
+    public function getModifiedPosts()
+    {
+        return $this->modifiedPosts;
     }
 
     /**

framework/core/src/Core/Posts/CommentPost.php

@@ -129,26 +129,6 @@ class CommentPost extends Post
         return $value;
     }
 
-    /**
-     * Define the relationship with the user who edited the post.
-     *
-     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
-     */
-    public function editUser()
-    {
-        return $this->belongsTo('Flarum\Core\Users\User', 'edit_user_id');
-    }
-
-    /**
-     * Define the relationship with the user who hid the post.
-     *
-     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
-     */
-    public function hideUser()
-    {
-        return $this->belongsTo('Flarum\Core\Users\User', 'hide_user_id');
-    }
-
     /**
      * Get text formatter instance.
      *

framework/core/src/Core/Posts/Post.php

@@ -111,6 +111,26 @@ class Post extends Model
         return $this->belongsTo('Flarum\Core\Users\User', 'user_id');
     }
 
+    /**
+     * Define the relationship with the user who edited the post.
+     *
+     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
+     */
+    public function editUser()
+    {
+        return $this->belongsTo('Flarum\Core\Users\User', 'edit_user_id');
+    }
+
+    /**
+     * Define the relationship with the user who hid the post.
+     *
+     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
+     */
+    public function hideUser()
+    {
+        return $this->belongsTo('Flarum\Core\Users\User', 'hide_user_id');
+    }
+
     /**
      * Get all posts, regardless of their type, by removing the
      * `RegisteredTypesScope` global scope constraints applied on this model.

framework/core/src/Forum/Actions/DiscussionAction.php

@@ -8,7 +8,7 @@ class DiscussionAction extends IndexAction
     {
         $response = $this->apiClient->send(app('flarum.actor'), 'Flarum\Api\Actions\Discussions\ShowAction', [
             'id' => $routeParams['id'],
-            'near' => $routeParams['near']
+            'page.near' => $routeParams['near']
         ]);
 
         // TODO: return an object instead of an array?