add ability to delete comments on responses in discussions.

common/static/coffee/spec/discussion/content_spec.coffee

@@ -2,7 +2,7 @@ describe 'All Content', ->
     beforeEach ->
         # TODO: figure out a better way of handling this
         # It is set up in main.coffee DiscussionApp.start
-        window.$$course_id = 'mitX/999/test'
+        window.$$course_id = 'edX/999/test'
         window.user = new DiscussionUser {id: '567'}
 
     describe 'Content', ->
@@ -10,7 +10,7 @@ describe 'All Content', ->
             @content = new Content {
                 id: '01234567',
                 user_id: '567',
-                course_id: 'mitX/999/test',
+                course_id: 'edX/999/test',
                 body: 'this is some content',
                 abuse_flaggers: ['123']
             }
@@ -22,7 +22,7 @@ describe 'All Content', ->
             @content.initialize
             expect(Content.contents['01234567']).toEqual @content
             expect(@content.get 'id').toEqual '01234567'
-            expect(@content.get 'user_url').toEqual '/courses/mitX/999/test/discussion/forum/users/567'
+            expect(@content.get 'user_url').toEqual '/courses/edX/999/test/discussion/forum/users/567'
             expect(@content.get 'children').toEqual []
             expect(@content.get 'comments').toEqual(jasmine.any(Comments))
 

common/static/coffee/spec/discussion/view/discussion_content_view_spec.coffee

@@ -25,7 +25,7 @@ describe "DiscussionContentView", ->
         @threadData = {
             id: '01234567',
             user_id: '567',
-            course_id: 'mitX/999/test',
+            course_id: 'edX/999/test',
             body: 'this is a thread',
             created_at: '2013-04-03T20:08:39Z',
             abuse_flaggers: ['123'],

common/static/coffee/spec/discussion/view/response_comment_show_view_spec.coffee

@@ -8,6 +8,8 @@ describe 'ResponseCommentShowView', ->
             <div class="response-body"><%- body %></div>
             <div class="discussion-flag-abuse notflagged" data-role="thread-flag" data-tooltip="report misuse">
             <i class="icon"></i><span class="flag-label"></span></div>
+            <div style="display:none" class="discussion-delete-comment action-delete" data-role="comment-delete" data-tooltip="Delete Comment" role="button" aria-pressed="false" tabindex="0">
+              <i class="icon icon-remove"></i><span class="sr delete-label">Delete Comment</span></div>
             <p class="posted-details">&ndash;posted <span class="timeago" title="<%- created_at %>"><%- created_at %></span> by
             <% if (obj.username) { %>
             <a href="<%- user_url %>" class="profile-link"><%- username %></a>
@@ -18,18 +20,17 @@ describe 'ResponseCommentShowView', ->
         """
 
         # set up a model for a new Comment
-        @response = new Comment {
+        @comment = new Comment {
                 id: '01234567',
                 user_id: '567',
-                course_id: 'mitX/999/test',
+                course_id: 'edX/999/test',
                 body: 'this is a response',
                 created_at: '2013-04-03T20:08:39Z',
                 abuse_flaggers: ['123']
                 roles: []
         }
-        @view = new ResponseCommentShowView({ model: @response })
-
-        # spyOn(DiscussionUtil, 'loadRoles').andReturn []
+        @view = new ResponseCommentShowView({ model: @comment })
+        spyOn(@view, "convertMath")
 
     it 'defines the tag', ->
         expect($('#jasmine-fixtures')).toExist
@@ -37,26 +38,36 @@ describe 'ResponseCommentShowView', ->
         expect(@view.el.tagName.toLowerCase()).toBe 'li'
 
     it 'is tied to the model', ->
-        expect(@view.model).toBeDefined();
+        expect(@view.model).toBeDefined()
 
     describe 'rendering', ->
 
         beforeEach ->
             spyOn(@view, 'renderAttrs')
             spyOn(@view, 'markAsStaff')
-            spyOn(@view, 'convertMath')
 
         it 'produces the correct HTML', ->
             @view.render()
             expect(@view.el.innerHTML).toContain('"discussion-flag-abuse notflagged"')
 
         it 'can be flagged for abuse', ->
-            @response.flagAbuse()
-            expect(@response.get 'abuse_flaggers').toEqual ['123', '567']
+            @comment.flagAbuse()
+            expect(@comment.get 'abuse_flaggers').toEqual ['123', '567']
 
         it 'can be unflagged for abuse', ->
             temp_array = []
             temp_array.push(window.user.get('id'))
-            @response.set("abuse_flaggers",temp_array)
-            @response.unflagAbuse()
-            expect(@response.get 'abuse_flaggers').toEqual []
+            @comment.set("abuse_flaggers",temp_array)
+            @comment.unflagAbuse()
+            expect(@comment.get 'abuse_flaggers').toEqual []
+
+    describe 'comment deletion', ->
+
+        it 'triggers the delete event when the delete icon is clicked', ->
+            DiscussionUtil.loadRoles []
+            @comment.updateInfo {ability: {'can_delete': true}}
+            triggerTarget = jasmine.createSpy()
+            @view.bind "comment:_delete", triggerTarget
+            @view.render()
+            @view.$el.find('.action-delete').click()
+            expect(triggerTarget).toHaveBeenCalled()

common/static/coffee/spec/discussion/view/response_comment_view_spec.coffee

+describe 'ResponseCommentView', ->
+    beforeEach ->
+
+        @comment = new Comment {
+                id: '01234567',
+                user_id: '567',
+                course_id: 'edX/999/test',
+                body: 'this is a response',
+                created_at: '2013-04-03T20:08:39Z',
+                abuse_flaggers: ['123']
+                roles: ['Student']
+        }
+        @view = new ResponseCommentView({ model: @comment })
+        spyOn(@view, "render")
+
+    describe '_delete', ->
+        beforeEach ->
+            @comment.updateInfo {ability: {can_delete: true}}
+            @event = jasmine.createSpyObj('event', ['preventDefault', 'target'])
+            spyOn(@comment, "remove")
+            spyOn(@view.$el, "remove")
+
+        setAjaxResult = (isSuccess) ->
+            spyOn($, "ajax").andCallFake(
+                (params) =>
+                    (if isSuccess then params.success else params.error) {}
+                    {always: ->}
+            )
+
+        it 'requires confirmation before deleting', ->
+            spyOn(window, "confirm").andReturn(false)
+            setAjaxResult(true)
+            @view._delete(@event)
+            expect(window.confirm).toHaveBeenCalled()
+            expect($.ajax).not.toHaveBeenCalled()
+            expect(@comment.remove).not.toHaveBeenCalled()
+
+        it 'removes the deleted comment object', ->
+            setAjaxResult(true)
+            @view._delete(@event)
+            expect(@comment.remove).toHaveBeenCalled()
+            expect(@view.$el.remove).toHaveBeenCalled()
+
+        it 'calls the ajax comment deletion endpoint', ->
+            setAjaxResult(true)
+            @view._delete(@event)
+            expect(@event.preventDefault).toHaveBeenCalled()
+            expect($.ajax).toHaveBeenCalled()
+            expect($.ajax.mostRecentCall.args[0].url._parts.path).toEqual('/courses/edX/999/test/discussion/comments/01234567/delete')
+
+        it 'handles ajax errors', ->
+            spyOn(DiscussionUtil, "discussionAlert")
+            setAjaxResult(false)
+            @view._delete(@event)
+            expect(@event.preventDefault).toHaveBeenCalled()
+            expect($.ajax).toHaveBeenCalled()
+            expect(@comment.remove).not.toHaveBeenCalled()
+            expect(@view.$el.remove).not.toHaveBeenCalled()
+            expect(DiscussionUtil.discussionAlert).toHaveBeenCalled()
+
+        it 'does not delete a comment if the permission is false', ->
+            @comment.updateInfo {ability: {'can_delete': false}}
+            spyOn(window, "confirm")
+            setAjaxResult(true)
+            @view._delete(@event)
+            expect(window.confirm).not.toHaveBeenCalled()
+            expect($.ajax).not.toHaveBeenCalled()
+            expect(@comment.remove).not.toHaveBeenCalled()
+            expect(@view.$el.remove).not.toHaveBeenCalled()
+

common/static/coffee/src/discussion/views/response_comment_show_view.coffee

 if Backbone?
   class @ResponseCommentShowView extends DiscussionContentView
 
+    events:
+        "click .action-delete": "_delete"
+
     tagName: "li"
 
     initialize: ->
         super()
         @model.on "change", @updateModelDetails
 
+    abilityRenderer:
+      can_delete:
+        enable: -> @$(".action-delete").show()
+        disable: -> @$(".action-delete").hide()
+
     render: ->
       @template = _.template($("#response-comment-show-template").html())
       params = @model.toJSON()
@@ -40,6 +48,8 @@ if Backbone?
       else if DiscussionUtil.isTA(@model.get("user_id"))
         @$el.find("a.profile-link").after('<span class="community-ta-label">' + gettext('Community TA') + '</span>')
 
+    _delete: (event) ->
+        @trigger "comment:_delete", event
 
     renderFlagged: =>
       if window.user.id in @model.get("abuse_flaggers") or (DiscussionUtil.isFlagModerator and @model.get("abuse_flaggers").length > 0)

common/static/coffee/src/discussion/views/response_comment_view.coffee

@@ -21,6 +21,7 @@ if Backbone?
         @editView = null
 
       @showView = new ResponseCommentShowView(model: @model)
+      @showView.bind "comment:_delete", @_delete
 
     renderSubView: (view) ->
       view.setElement(@$el)
@@ -29,3 +30,24 @@ if Backbone?
 
     renderShowView: () ->
       @renderSubView(@showView)
+
+    _delete: (event) =>
+      event.preventDefault()
+      if not @model.can('can_delete')
+        return
+      if not confirm gettext("Are you sure you want to delete this comment?")
+        return
+      url = @model.urlFor('_delete')
+      $elem = $(event.target)
+      DiscussionUtil.safeAjax
+        $elem: $elem
+        url: url
+        type: "POST"
+        success: (response, textStatus) =>
+          @model.remove()
+          @$el.remove()
+        error: =>
+          DiscussionUtil.discussionAlert(
+            gettext("Sorry"),
+            gettext("We had some trouble deleting this comment. Please try again.")
+          )

common/static/coffee/src/discussion/views/thread_response_view.coffee

@@ -91,6 +91,7 @@ if Backbone?
           body: body
         success: (response, textStatus) ->
           comment.set(response.content)
+          comment.updateInfo(response.annotated_content_info)
           view.render() # This is just to update the id for the most part, but might be useful in general
 
     _delete: (event) =>

lms/static/sass/_discussion.scss

@@ -2529,7 +2529,7 @@ body.discussion {
 display:none;
 }
 
-.discussion-flag-abuse {
+.discussion-flag-abuse, .discussion-delete-comment {
   font-size: 12px;
   float:right;
   padding-right: 5px;
@@ -2542,7 +2542,7 @@ display:none;
     opacity: 1.0;
   }
 }
-    
+
 .notflagged .icon {
   display: block;
   color: #333;

lms/templates/discussion/_underscore_templates.html

@@ -166,6 +166,8 @@
     <div class="response-body">${'<%- body %>'}</div>
     <div class="discussion-flag-abuse notflagged" data-role="thread-flag" data-tooltip="${_('Report Misuse') | h}" role="button" aria-pressed="false" tabindex="0">
       <i class="icon icon-flag"></i><span class="sr flag-label">${_("Report Misuse")}</span></div>
+    <div style="display: none" class="discussion-delete-comment action-delete" data-tooltip="${_('Delete Comment') | h}" role="button" tabindex="0">
+      <i class="icon icon-remove"></i><span class="sr">${_("Delete Comment")}</span></div>
       <% 
       js_block = u"""
         interpolate(