Centralize MessageBus post updates

After this change, only two files directly publish to MessageBus with a
topic interpolated in the channel: Post and TopicUser.

app/assets/javascripts/discourse/controllers/topic.js.es6

@@ -513,8 +513,13 @@ export default ObjectController.extend(Discourse.SelectedPostsCount, {
         return;
       }
 
-      // Add the new post into the stream
+      if (data.type === "created") {
         postStream.triggerNewPostInStream(data.id);
+        return;
+      }
+
+      // log a warning
+      Em.Logger.warn("unknown topic bus message type", data);
     });
   },
 

app/jobs/regular/process_post.rb

@@ -18,13 +18,7 @@ module Jobs
       # If we changed the document, save it
       if cp.dirty?
         post.update_column(:cooked, cp.html)
-
-        MessageBus.publish("/topic/#{post.topic_id}", {
-            type: "revised",
-            id: post.id,
-            updated_at: Time.now,
-            post_number: post.post_number
-        }, group_ids: post.topic.secure_group_ids )
+        post.publish_change_to_clients! :revised
       end
     end
 

app/models/post.rb

@@ -87,6 +87,15 @@ class Post < ActiveRecord::Base
     end
   end
 
+  def publish_change_to_clients!(type)
+    MessageBus.publish("/topic/#{topic_id}", {
+        id: id,
+        post_number: post_number,
+        updated_at: Time.now,
+        type: type
+    }, group_ids: topic.secure_group_ids)
+  end
+
   def trash!(trashed_by=nil)
     self.topic_links.each(&:destroy)
     super(trashed_by)

app/models/post_action.rb

@@ -375,13 +375,7 @@ class PostAction < ActiveRecord::Base
 
   def notify_subscribers
     if (is_like? || is_flag?) && post
-      MessageBus.publish("/topic/#{post.topic_id}",{
-                      id: post.id,
-                      post_number: post.post_number,
-                      type: "acted"
-                    },
-                    group_ids: post.topic.secure_group_ids
-      )
+      post.publish_change_to_clients! :acted
     end
   end
 

lib/post_creator.rb

@@ -270,14 +270,7 @@ class PostCreator
     return if @opts[:import_mode]
     return unless @post.post_number > 1
 
-    MessageBus.publish("/topic/#{@post.topic_id}",{
-                    id: @post.id,
-                    created_at: @post.created_at,
-                    user: BasicUserSerializer.new(@post.user).as_json(root: false),
-                    post_number: @post.post_number
-                  },
-                  group_ids: @topic.secure_group_ids
-    )
+    @post.publish_change_to_clients! :created
   end
 
   def extract_links

lib/post_destroyer.rb

@@ -51,7 +51,7 @@ class PostDestroyer
 
   def staff_recovered
     @post.recover!
-    publish("recovered")
+    @post.publish_change_to_clients! :recovered
   end
 
   # When a post is properly deleted. Well, it's still soft deleted, but it will no longer
@@ -75,21 +75,8 @@ class PostDestroyer
       update_associated_category_latest_topic
       update_user_counts
     end
-    publish("deleted")
-  end
 
-  def publish(message)
-    # edge case, topic is already destroyed
-    return unless @post.topic
-
-    MessageBus.publish("/topic/#{@post.topic_id}",{
-                    id: @post.id,
-                    post_number: @post.post_number,
-                    updated_at: @post.updated_at,
-                    type: message
-                  },
-                  group_ids: @post.topic.secure_group_ids
-    )
+    @post.publish_change_to_clients! :deleted if @post.topic
   end
 
   # When a user 'deletes' their own post. We just change the text.
@@ -100,6 +87,9 @@ class PostDestroyer
       @post.update_flagged_posts_count
       @post.topic_links.each(&:destroy)
     end
+
+    # covered by PostRevisor
+    # @post.publish_change_to_clients! :revised
   end
 
   def user_recovered
@@ -109,6 +99,9 @@ class PostDestroyer
       @post.revise(@user, @post.revisions.last.modifications["raw"][0], force_new_version: true)
       @post.update_flagged_posts_count
     end
+
+    # covered by PostRevisor
+    # @post.publish_change_to_clients! :revised
   end
 
 

lib/post_revisor.rb

@@ -21,6 +21,7 @@ class PostRevisor
     @opts = opts
     @new_raw = TextCleaner.normalize_whitespaces(new_raw).strip
 
+    # TODO this is not in a transaction - dangerous!
     return false unless should_revise?
     @post.acting_user = @editor
     revise_post
@@ -30,7 +31,7 @@ class PostRevisor
     update_topic_word_counts
     @post.advance_draft_sequence
     PostAlerter.new.after_save_post(@post)
-    publish_revision
+    @post.publish_change_to_clients! :revised
     BadgeGranter.queue_badge_grant(Badge::Trigger::PostRevision, post: @post)
 
     true
@@ -38,17 +39,6 @@ class PostRevisor
 
   private
 
-  def publish_revision
-    MessageBus.publish("/topic/#{@post.topic_id}",{
-                    id: @post.id,
-                    post_number: @post.post_number,
-                    updated_at: @post.updated_at,
-                    type: "revised"
-                  },
-                  group_ids: @post.topic.secure_group_ids
-    )
-  end
-
   def should_revise?
     @post.raw != @new_raw || @opts[:changed_owner]
   end