more refactoring; enabled partial re-rendering for votes, endorse, and closed

lms/djangoapps/django_comment_client/base/views.py

@@ -51,7 +51,8 @@ def ajax_content_response(request, course_id, content, template_name):
         'content': content,
     }
     html = render_to_string(template_name, context)
-    annotated_content_info = utils.get_annotated_content_info(course_id, content, request.user)
+    user_info = cc.User.from_django_user(request.user).to_dict()
+    annotated_content_info = utils.get_annotated_content_info(course_id, content, request.user, user_info)
     return JsonResponse({
         'html': html,
         'content': content,

lms/djangoapps/django_comment_client/forum/views.py

@@ -15,7 +15,6 @@ from django_comment_client.permissions import check_permissions_by_view
 from django_comment_client.utils import merge_dict, extract, strip_none
 
 import json
-import dateutil
 import django_comment_client.utils as utils
 import comment_client as cc
 
@@ -64,14 +63,17 @@ def render_discussion(request, course_id, threads, *args, **kwargs):
         'user': (lambda: reverse('django_comment_client.forum.views.user_profile', args=[course_id, user_id])),
     }[discussion_type]()
 
-    annotated_content_infos = map(lambda x: utils.get_annotated_content_infos(course_id, x, request.user), threads)
-    annotated_content_info = reduce(merge_dict, annotated_content_infos, {})
+    user_info = cc.User.from_django_user(request.user).to_dict()
+
+    def infogetter(thread):
+        return utils.get_annotated_content_infos(course_id, thread, request.user, user_info)
+
+    annotated_content_info = reduce(merge_dict, map(infogetter, threads), {})
 
     context = {
         'threads': threads,
         'discussion_id': discussion_id,
         'user_id': user_id,
-        'user_info': json.dumps(cc.User.from_django_user(request.user).to_dict()),
         'course_id': course_id,
         'request': request,
         'performed_search': _should_perform_search(request),
@@ -166,12 +168,13 @@ def render_single_thread(request, discussion_id, course_id, thread_id):
     
     thread = cc.Thread.find(thread_id).retrieve(recursive=True).to_dict()
 
-    annotated_content_info = utils.get_annotated_content_infos(course_id, thread=thread, user=request.user)
+    user_info = cc.User.from_django_user(request.user).to_dict()
+
+    annotated_content_info = utils.get_annotated_content_infos(course_id, thread=thread, user=request.user, user_info=user_info)
 
     context = {
         'discussion_id': discussion_id,
         'thread': thread,
-        'user_info': json.dumps(cc.User.from_django_user(request.user).to_dict()),
         'annotated_content_info': json.dumps(annotated_content_info),
         'course_id': course_id,
         'request': request,
@@ -183,8 +186,9 @@ def single_thread(request, course_id, discussion_id, thread_id):
 
     if request.is_ajax():
         
+        user_info = cc.User.from_django_user(request.user).to_dict()
         thread = cc.Thread.find(thread_id).retrieve(recursive=True)
-        annotated_content_info = utils.get_annotated_content_infos(course_id, thread, request.user)
+        annotated_content_info = utils.get_annotated_content_infos(course_id, thread, request.user, user_info=user_info)
         context = {'thread': thread.to_dict(), 'course_id': course_id}
         html = render_to_string('discussion/_ajax_single_thread.html', context)
 

lms/djangoapps/django_comment_client/utils.py

@@ -160,23 +160,32 @@ class QueryCountDebugMiddleware(object):
             logging.info('%s queries run, total %s seconds' % (len(connection.queries), total_time))
         return response
 
-def get_annotated_content_info(course_id, content, user):
+def get_annotated_content_info(course_id, content, user, user_info):
+    voted = ''
+    if content['id'] in user_info['upvoted_ids']:
+        voted = 'up'
+    elif content['id'] in user_info['downvoted_ids']:
+        voted = 'down'
     return {
+        'voted': voted,
+        'subscribed': content['id'] in user_info['subscribed_thread_ids'],
+        'ability': {
             'editable': check_permissions_by_view(user, course_id, content, "update_thread" if content['type'] == 'thread' else "update_comment"),
             'can_reply': check_permissions_by_view(user, course_id, content, "create_comment" if content['type'] == 'thread' else "create_sub_comment"),
             'can_endorse': check_permissions_by_view(user, course_id, content, "endorse_comment") if content['type'] == 'comment' else False,
             'can_delete': check_permissions_by_view(user, course_id, content, "delete_thread" if content['type'] == 'thread' else "delete_comment"),
             'can_openclose': check_permissions_by_view(user, course_id, content, "openclose_thread") if content['type'] == 'thread' else False,
             'can_vote': check_permissions_by_view(user, course_id, content, "vote_for_thread" if content['type'] == 'thread' else "vote_for_comment"),
+        },
     }
 
-def get_annotated_content_infos(course_id, thread, user):
+def get_annotated_content_infos(course_id, thread, user, user_info):
     infos = {}
-    def _annotate(content):
-        infos[str(content['id'])] = get_annotated_content_info(course_id, content, user)
+    def annotate(content):
+        infos[str(content['id'])] = get_annotated_content_info(course_id, content, user, user_info)
         for child in content.get('children', []):
-            _annotate(child)
-    _annotate(thread)
+            annotate(child)
+    annotate(thread)
     return infos
 
 def render_mustache(template_name, dictionary, *args, **kwargs):

lms/static/coffee/src/backbone_discussion/content.coffee

@@ -9,60 +9,107 @@ class @Content extends Backbone.Model
     can_delete: '.admin-delete'
     can_openclose: '.admin-openclose'
     
-  isUpvoted: ->
-    DiscussionUtil.isUpvoted @id
+  urlMappers: {}
 
-  isDownvoted: ->
-    DiscussionUtil.isDownvoted @id
+  urlFor: (name) ->
+    @urlMappers[name].apply(@)
 
   can: (action) ->
     DiscussionUtil.getContentInfo @id, action
 
-  thread_id: ->
-    if @get('type') == "comment" then @get('thread_id') else @id
+  updateInfo: (info) ->
+    @set('ability', info.ability)
+    @set('voted', info.voted)
+    @set('subscribed', info.subscribed)
+
+  addComment: (comment) ->
+    @get('children').push comment
+    model = new Comment $.extend {}, comment, { thread: @get('thread') }
+    @get('comments').add model
+    model
+
+  resetComments: (children) ->
+    @set 'children', []
+    @set 'comments', new Comments()
+    for comment in (children || [])
+      @addComment comment
 
   initialize: ->
-    @set('comments', new Comments())
-    if @get('children')
-      @get('comments').reset @get('children'), {silent: false}
+    DiscussionUtil.addContent @id, @
+    @resetComments(@get('children'))
+    
 
 class @ContentView extends Backbone.View
 
   $: (selector) ->
     @$local.find(selector)
 
-  discussionContent: ->
+  partial:
+    endorsed: (endorsed) ->
+      if endorsed
+        @$el.addClass("endorsed")
+      else
+        @$el.removeClass("endorsed")
+
+    closed: (closed) -> # we should just re-render the whole thread, or update according to new abilities
+      if closed
+        @$el.addClass("closed")
+        @$(".admin-openclose").text "Re-open Thread"
+      else
+        @$el.removeClass("closed")
+        @$(".admin-openclose").text "Close Thread"
+
+    voted: (voted) ->
+      @$(".discussion-vote-up").removeClass("voted") if voted != "up"
+      @$(".discussion-vote-down").removeClass("voted") if voted != "down"
+      @$(".discussion-vote-#{voted}").addClass("voted") if voted in ["up", "down"]
+
+    votes_point: (votes_point) ->
+      @$(".discussion-votes-point").html(votes_point)
+      
+    subscribed: (subscribed) -> #later
+
+    ability: (ability) ->
+      for action, elemSelector of @model.actions
+        if not ability[action]
+          @$(elemSelector).remove()
+
+  $discussionContent: ->
     @_discussionContent ||= @$el.children(".discussion-content")
 
+  $showComments: ->
+    @_showComments ||= @$(".discussion-show-comments")
+
+  updateShowComments: ->
+    if @showed
+      @$showComments().html @$showComments().html().replace "Show", "Hide"
+    else
+      @$showComments().html @$showComments().html().replace "Hide", "Show"
+
+  retrieved: ->
+    @$showComments().hasClass("retrieved")
+      
   hideSingleThread: (event) ->
-    $showComments = @$(".discussion-show-comments")
     @$el.children(".comments").hide()
     @showed = false
-    $showComments.html $showComments.html().replace "Hide", "Show"
+    @updateShowComments()
 
   showSingleThread: (event) ->
-    $showComments = @$(".discussion-show-comments")
-    retrieved = not $showComments.hasClass("first-time") and @model.get("children") != undefined
-    if retrieved
+    if @retrieved()
       @$el.children(".comments").show()
-      $showComments.html $showComments.html().replace "Show", "Hide"
       @showed = true
+      @updateShowComments()
     else
-      discussion_id = @model.discussion.id
-      url = DiscussionUtil.urlFor('retrieve_single_thread', discussion_id, @model.id)
-      DiscussionUtil.safeAjax
-        $elem: $.merge @$(".thread-title"), @$(".discussion-show-comments")
-        url: url
-        type: "GET"
-        dataType: 'json'
-        success: (response, textStatus) =>
-          DiscussionUtil.bulkExtendContentInfo response['annotated_content_info']
+      $elem = $.merge @$(".thread-title"), @$showComments()
+      url = @model.urlFor('retrieve_single_thread')
+      DiscussionUtil.get $elem, url, (response, textStatus) =>
         @showed = true
-          $showComments.html $showComments.html().replace "Show", "Hide"
-          @$el.append(response['html'])
-          @model.set('children', response.content.children)
-          @model.get('comments').reset response.content.children, {silent: false}
+        @updateShowComments()
+        @$showComments().addClass("retrieved")
+        @$el.children(".comments").replaceWith response.html
+        @model.resetComments response.content.children
         @initCommentViews()
+        DiscussionUtil.bulkUpdateContentInfo response.annotated_content_info
 
   toggleSingleThread: (event) ->
     if @showed
@@ -83,12 +130,11 @@ class @ContentView extends Backbone.View
     if $replyView.length
       $replyView.show()
     else
-      thread_id = @model.thread_id()
-      view =
-        id: @model.id
-        showWatchCheckbox: not DiscussionUtil.isSubscribed(thread_id, "thread")
+      view = {}
+      view.id = @model.id
+      view.showWatchCheckbox = not @model.get('thread').get('subscribed')
       html = Mustache.render DiscussionUtil.getTemplate('_reply'), view
-      @discussionContent().append html
+      @$discussionContent().append html
       DiscussionUtil.makeWmdEditor @$el, $.proxy(@$, @), "reply-body"
       @$(".discussion-submit-post").click $.proxy(@submitReply, @)
       @$(".discussion-cancel-post").click $.proxy(@cancelReply, @)
@@ -96,13 +142,7 @@ class @ContentView extends Backbone.View
     @$(".discussion-edit").hide()
 
   submitReply: (event) ->
-    if @model.get('type') == 'thread'
-      url = DiscussionUtil.urlFor('create_comment', @model.id)
-    else if @model.get('type') == 'comment'
-      url = DiscussionUtil.urlFor('create_sub_comment', @model.id)
-    else
-      console.error "unrecognized model type #{@model.get('type')}"
-      return
+    url = @model.urlFor('reply')
 
     body = DiscussionUtil.getWmdContent @$el, $.proxy(@$, @), "reply-body"
 
@@ -122,19 +162,13 @@ class @ContentView extends Backbone.View
       success: (response, textStatus) =>
         DiscussionUtil.clearFormErrors @$(".discussion-errors")
         $comment = $(response.html)
-        @$el.children(".comments").prepend($comment)
+        @$el.children(".comments").prepend $comment
         DiscussionUtil.setWmdContent @$el, $.proxy(@$, @), "reply-body", ""
-        #DiscussionUtil.setContentInfo response.content['id'], 'can_reply', true
-        #DiscussionUtil.setContentInfo response.content['id'], 'editable', true
-        comment = new Comment(response.content)
-        DiscussionUtil.extendContentInfo comment.id, response['annotated_content_info']
-        @model.get('children').push(response.content)
-        @model.get('comments').add(comment)
+        comment = @model.addComment response.content
+        comment.updateInfo response.annotated_content_info
         commentView = new CommentView el: $comment[0], model: comment
-        @$(".discussion-reply-new").hide()
-        @$(".discussion-reply").show()
-        @$(".discussion-edit").show()
-        @discussionContent().attr("status", "normal")
+        @cancelReply()
+
   cancelReply: ->
     $replyView = @$(".discussion-reply-new")
     if $replyView.length
@@ -143,77 +177,42 @@ class @ContentView extends Backbone.View
     @$(".discussion-edit").show()
 
   unvote: (event) ->
-    url = DiscussionUtil.urlFor("undo_vote_for_#{@model.get('type')}", @model.id)
-    DiscussionUtil.safeAjax
-      $elem: @$(".discussion-vote")
-      url: url
-      type: "POST"
-      dataType: "json"
-      success: (response, textStatus) =>
-        if textStatus == "success"
-          @$(".discussion-vote").removeClass("voted")
-          @$(".discussion-votes-point").html response.votes.point
-
-  vote: (event) ->
+    url = @model.urlFor('unvote')
+    $elem = @$(".discussion-vote")
+    DiscussionUtil.post $elem, url, {}, (response, textStatus) =>
+      @model.set('voted', '')
+      @model.set('votes_point', response.votes.point)
+
+  vote: (event, value) ->
+    url = @model.urlFor("#{value}vote")
+    $elem = @$(".discussion-vote")
+    DiscussionUtil.post $elem, url, {}, (response, textStatus) =>
+      @model.set('voted', value)
+      @model.set('votes_point', response.votes.point)
+
+  toggleVote: (event) ->
     $elem = $(event.target)
-    if $elem.hasClass("voted")
+    value = $elem.attr("value")
+    if @model.get("voted") == value
       @unvote(event)
     else
-      value = $elem.attr("value")
-      url = Discussion.urlFor("#{value}vote_#{@model.get('type')}", @model.id)
-      DiscussionUtil.safeAjax
-        $elem: @$(".discussion-vote")
-        url: url
-        type: "POST"
-        dataType: "json"
-        success: (response, textStatus) =>
-          if textStatus == "success"
-            @$(".discussion-vote").removeClass("voted")
-            @$(".discussion-vote-#{value}").addClass("voted")
-            @$(".discussion-votes-point").html response.votes.point
+      @vote(event, value)
 
-  endorse: (event) ->
-    url = DiscussionUtil.urlFor('endorse_comment', @model.id)
-    endorsed = not @$el.hasClass("endorsed")
-    Discussion.safeAjax
-      $elem: $(event.target)
-      url: url
-      type: "POST"
-      dataType: "json"
-      data: {endorsed: endorsed}
-      success: (response, textStatus) =>
-        if textStatus == "success"
-          if endorsed
-            @$el.addClass("endorsed")
-          else
-            @$el.removeClass("endorsed")
+  toggleEndorse: (event) ->
+    $elem = $(event.target)
+    url = @model.urlFor('endorse')
+    endorsed = @model.get('endorsed')
+    data = { endorsed: not endorsed }
+    DiscussionUtil.post $elem, url, data, (response, textStatus) =>
+      @model.set('endorsed', not endorsed)
 
-  close: (event) ->
-    url = DiscussionUtil.urlFor('openclose_thread', @model.id)
-    closed = undefined
-    text = $(event.target).text()
-    if text.match(/Close/)
-      closed = true
-    else if text.match(/[Oo]pen/)
-      closed = false
-    else
-      console.log "Unexpected text " + text + "for open/close thread."
-    Discussion.safeAjax
-      $elem: $(event.target)
-      url: url
-      type: "POST"
-      dataType: "json"
-      data: {closed: closed}
-      success: (response, textStatus) =>
-        if textStatus == "success"
-          if closed
-            @$el.addClass("closed")
-            $(event.target).text "Re-open Thread"
-          else
-            @$el.removeClass("closed")
-            $(event.target).text "Close Thread"
-      error: (response, textStatus, e) ->
-        console.log e
+  toggleClosed: (event) ->
+    $elem = $(event.target)
+    url = @model.urlFor('close')
+    closed = @model.get('closed')
+    data = { closed: not closed }
+    DiscussionUtil.post $elem, url, data, (response, textStatus) =>
+      @model.set('closed', not closed)
 
   edit: ->
     $local(".discussion-content-wrapper").hide()
@@ -227,7 +226,7 @@ class @ContentView extends Backbone.View
         body: $local(".thread-raw-body").html()
         tags: $local(".thread-raw-tags").html()
       }
-      @discussionContent().append Mustache.render Discussion.editThreadTemplate, view
+      @$discussionContent().append Mustache.render Discussion.editThreadTemplate, view
       Discussion.makeWmdEditor $content, $local, "thread-body-edit"
       $local(".thread-tags-edit").tagsInput Discussion.tagsInputOptions()
       $local(".discussion-submit-update").unbind("click").click -> handleSubmitEditThread(this)
@@ -247,7 +246,7 @@ class @ContentView extends Backbone.View
         error: Discussion.formErrorHandler($local(".discussion-update-errors"))
         success: (response, textStatus) ->
           Discussion.clearFormErrors($local(".discussion-update-errors"))
-          @discussionContent().replaceWith(response.html)
+          @$discussionContent().replaceWith(response.html)
           Discussion.extendContentInfo response.content['id'], response['annotated_content_info']
           Discussion.initializeContent($content)
           Discussion.bindContentEvents($content)
@@ -274,15 +273,15 @@ class @ContentView extends Backbone.View
         console.log e
 
   events:
-    "click .thread-title": "showSingleThread"
-    "click .discussion-show-comments": "showSingleThread"
+    "click .thread-title": "toggleSingleThread"
+    "click .discussion-show-comments": "toggleSingleThread"
     "click .discussion-reply-thread": "reply"
     "click .discussion-reply-comment": "reply"
     "click .discussion-cancel-reply": "cancelReply"
-    "click .discussion-vote-up": "vote"
-    "click .discussion-vote-down": "vote"
-    "click .admin-endorse": "endorse"
-    "click .admin-openclose": "close"
+    "click .discussion-vote-up": "toggleVote"
+    "click .discussion-vote-down": "toggleVote"
+    "click .admin-endorse": "toggleEndorse"
+    "click .admin-openclose": "toggleClosed"
     "click .admin-edit": "edit"
     "click .admin-delete": "delete"
 
@@ -290,57 +289,65 @@ class @ContentView extends Backbone.View
     @$local = @$el.children(".local")
     @$delegateElement = @$local
 
-  initFollowThread: ->
-    $el.children(".discussion-content")
-       .find(".follow-wrapper")
-       .append(DiscussionUtil.subscriptionLink('thread', id))
-
-  initVote: ->
-    if @model.isUpvoted()
-      @$(".discussion-vote-up").addClass("voted")
-    else if @model.isDownvoted()
-      @$(".discussion-vote-down").addClass("voted")
-
   initBody: ->
     $contentBody = @$(".content-body")
     $contentBody.html DiscussionUtil.postMathJaxProcessor DiscussionUtil.markdownWithHighlight $contentBody.html()
     MathJax.Hub.Queue ["Typeset", MathJax.Hub, $contentBody.attr("id")]
 
-  initActions: ->
-    for action, elemSelector of @model.actions
-      if not @model.can action
-        @$(elemSelector).remove()
-
   initTimeago: ->
     @$("span.timeago").timeago()
 
   initPermalink: ->
+    @$(".discussion-permanent-link").attr "href", @model.permalink()
 
-    if @model.get('type') == 'thread'
-      discussion_id = @model.get('commentable_id')
-      permalink = Discussion.urlFor("permanent_link_thread", discussion_id, @model.id)
-    else
-      thread_id = @model.get('thread_id')
-      discussion_id = @$el.parents(".thread").attr("_discussion_id")
-      permalink = Discussion.urlFor("permanent_link_comment", discussion_id, thread_id, @model.id)
+  renderPartial: ->
+    for attr, value of @model.changedAttributes()
+      if @partial[attr]
+        @partial[attr].apply(@, [value])
 
-    @$(".discussion-permanent-link").attr "href", permalink
+  initBindings: ->
+    @model.view = @
+    @model.bind('change', @renderPartial, @)
 
   initialize: ->
-    @model.view = @
+    @initBindings()
     @initLocal()
-    @initVote()
     @initTimeago()
     @initBody()
     @initPermalink()
-    @initActions()
     @initCommentViews()
     
 class @Thread extends @Content
+  urlMappers:
+    'retrieve_single_thread': -> DiscussionUtil.urlFor('retrieve_single_thread', @discussion.id, @id)
+    'reply': -> DiscussionUtil.urlFor('create_comment', @id)
+    'unvote': -> DiscussionUtil.urlFor("undo_vote_for_#{@get('type')}", @id)
+    'upvote': -> DiscussionUtil.urlFor("upvote_#{@get('type')}", @id)
+    'downvote': -> DiscussionUtil.urlFor("downvote_#{@get('type')}", @id)
+    'close': -> DiscussionUtil.urlFor('openclose_thread', @id)
+
+  initialize: ->
+    @set('thread', @)
+    super()
+
+  permalink: ->
+    discussion_id = @get('commentable_id')
+    return Discussion.urlFor("permanent_link_thread", discussion_id, @id)
 
 class @ThreadView extends @ContentView
 
 class @Comment extends @Content
+  urlMappers:
+    'reply': -> DiscussionUtil.urlFor('create_sub_comment', @id)
+    'unvote': -> DiscussionUtil.urlFor("undo_vote_for_#{@get('type')}", @id)
+    'upvote': -> DiscussionUtil.urlFor("upvote_#{@get('type')}", @id)
+    'downvote': -> DiscussionUtil.urlFor("downvote_#{@get('type')}", @id)
+    'endorse': -> DiscussionUtil.urlFor('endorse_comment', @id)
+
+  permalink: ->
+    thread_id = @get('thread').id
+    discussion_id = @get('thread').get('commentable_id')
+    return Discussion.urlFor("permanent_link_comment", discussion_id, thread_id, @id)
 
 class @CommentView extends @ContentView
 

lms/static/coffee/src/backbone_discussion/discussion.coffee

@@ -2,8 +2,9 @@ class @Discussion extends Backbone.Collection
   model: Thread
   initialize: ->
 
+    DiscussionUtil.addDiscussion @id, @
+    
     @bind "add", (item) =>
-      console.log item
       item.discussion = @
 
   find: (id) ->

lms/static/coffee/src/backbone_discussion/main.coffee

 $ ->
 
+  window.$$contents = {}
+  window.$$discussions = {}
+
   $(".discussion-module").each (index, elem) ->
     view = new DiscussionModuleView(el: elem)
 
@@ -8,3 +11,5 @@ $ ->
     discussion = new Discussion()
     discussion.reset(discussionData, {silent: false})
     view = new DiscussionView(el: elem, model: discussion)
+
+  DiscussionUtil.bulkUpdateContentInfo(window.$$annotated_content_info)

lms/static/coffee/src/backbone_discussion/utils.coffee

@@ -12,26 +12,17 @@ class @DiscussionUtil
       id = $(id).attr("_id")
     return $$discussion_data[id]
 
-  @getContentInfo: (id, attr) ->
-    if not window.$$annotated_content_info?
-      window.$$annotated_content_info = {}
-    (window.$$annotated_content_info[id] || {})[attr]
-
-  @setContentInfo: (id, attr, value) ->
-    if not window.$$annotated_content_info?
-      window.$$annotated_content_info = {}
-    window.$$annotated_content_info[id] ||= {}
-    window.$$annotated_content_info[id][attr] = value
-
-  @extendContentInfo: (id, newInfo) ->
-    if not window.$$annotated_content_info?
-      window.$$annotated_content_info = {}
-    window.$$annotated_content_info[id] = newInfo
-
-  @bulkExtendContentInfo: (newInfos) ->
-    if not window.$$annotated_content_info?
-      window.$$annotated_content_info = {}
-    window.$$annotated_content_info = $.extend window.$$annotated_content_info, newInfos
+  @addContent: (id, content) -> window.$$contents[id] = content
+
+  @getContent: (id) -> window.$$contents[id]
+
+  @addDiscussion: (id, discussion) -> window.$$discussions[id] = discussion
+
+  @getDiscussion: (id) -> window.$$discussions[id]
+  
+  @bulkUpdateContentInfo: (infos) ->
+    for id, info of infos
+      @getContent(id).updateInfo(info)
 
   @generateDiscussionLink: (cls, txt, handler) ->
     $("<a>").addClass("discussion-link")
@@ -79,9 +70,22 @@ class @DiscussionUtil
     $.ajax(params).always ->
       $elem.removeAttr("disabled")
 
-  @handleAnchorAndReload: (response) ->
-    #window.location = window.location.pathname + "#" + response['id']
-    window.location.reload()
+  @get: ($elem, url, success) ->
+    @safeAjax
+      $elem: $elem
+      url: url
+      type: "GET"
+      dataType: "json"
+      success: success
+
+  @post: ($elem, url, data, success) ->
+    @safeAjax
+      $elem: $elem
+      url: url
+      type: "POST"
+      dataType: "json"
+      data: data
+      success: success
 
   @bindLocalEvents: ($local, eventsHandler) ->
     for eventSelector, handler of eventsHandler
@@ -98,22 +102,6 @@ class @DiscussionUtil
     defaultText: "Tag your post: press enter after each tag"
     removeWithBackspace: true
 
-  @isSubscribed: (id, type) ->
-    $$user_info? and (
-      if type == "thread"
-        id in $$user_info.subscribed_thread_ids
-      else if type == "commentable" or type == "discussion"
-        id in $$user_info.subscribed_commentable_ids
-      else
-        id in $$user_info.subscribed_user_ids
-    )
-
-  @isUpvoted: (id) ->
-    $$user_info? and (id in $$user_info.upvoted_ids)
-
-  @isDownvoted: (id) ->
-    $$user_info? and (id in $$user_info.downvoted_ids)
-
   @formErrorHandler: (errorsField) ->
     (xhr, textStatus, error) ->
       response = JSON.parse(xhr.responseText)

lms/static/coffee/src/discussion/content.coffee

@@ -85,6 +85,7 @@ initializeFollowThread = (thread) ->
           Discussion.extendContentInfo response.content['id'], response['annotated_content_info']
           Discussion.initializeContent($comment)
           Discussion.bindContentEvents($comment)
+          @cancelReply()
           $local(".discussion-reply-new").hide()
           $local(".discussion-reply").show()
           $local(".discussion-edit").show()

lms/templates/discussion/_content_renderer.html

@@ -5,11 +5,9 @@
 </%def>
 
 <%def name="render_content_with_comments(content)">
-<div class="${content['type']}${helpers.show_if(' endorsed', content.get('endorsed'))}" _id="${content['id']}" _discussion_id="${content.get('commentable_id', '')}" _author_id="${helpers.show_if(content['user_id'], not content.get('anonymous'))}">
+  <div class="${content['type']}${helpers.show_if(' endorsed', content.get('endorsed'))}" _id="${content['id']}" _discussion_id="${content.get('commentable_id', '')}" _author_id="${helpers.show_if(content['user_id'], not content.get('anonymous'))}">
     ${render_content(content)}
-    % if content.get('children') is not None:
-      ${render_comments(content['children'])}
-    % endif
+    ${render_comments(content.get('children', []))}
   </div>
 </%def>
 

lms/templates/discussion/_js_data.html

 <%! from django.template.defaultfilters import escapejs %>
 
 <script type="text/javascript">
-  var $$user_info = JSON.parse("${user_info | escapejs}");
   var $$course_id = "${course_id | escapejs}";
   if (typeof $$annotated_content_info === undefined) {
     var $$annotated_content_info = {};