Fix rubric with staff grading

common/lib/xmodule/xmodule/js/src/combinedopenended/display.coffee

@@ -6,7 +6,7 @@ class @Rubric
   constructor: (el) ->
     @el = el
 
-  initialize: (location) ->
+  initialize: (location) =>
     @$(@rubric_sel).data("location", location)
     @$('input[class="score-selection"]').change @tracking_callback
     # set up the hotkeys
@@ -53,7 +53,7 @@ class @Rubric
       @category = @$(@categories[@category_index])
       @category.prepend('> ')
     
-  tracking_callback: (event) ->
+  tracking_callback: (event) =>
     target_selection = $(event.target).val()
     # chop off the beginning of the name so that we can get the number of the category
     category = $(event.target).data("category")
@@ -76,14 +76,14 @@ class @Rubric
 
     return score_lst
 
-  get_total_score: () ->
+  get_total_score: () =>
     score_lst = @get_score_list()
     tot = 0
     for score in score_lst
       tot += parseInt(score)
     return tot
 
-  check_complete: () ->
+  check_complete: () =>
      # check to see whether or not any categories have not been scored
     num_categories = @$(@rubric_category_sel).length
     for i in [0..(num_categories-1)]

lms/static/coffee/src/staff_grading/staff_grading.coffee

@@ -223,12 +223,12 @@ class @StaffGrading
   setup_score_selection: =>
     @score_selection_container.html(@rubric)
     $('input[class="score-selection"]').change => @graded_callback()
-    Rubric.initialize(@location, @el)
-
+    @rub = new Rubric(@el)
+    @rub.initialize(@location)
 
   graded_callback: () =>
    # show button if we have scores for all categories
-    if Rubric.check_complete()
+    if @rub.check_complete()
       @state = state_graded
       @submit_button.show()
 
@@ -236,7 +236,7 @@ class @StaffGrading
     #Previously, responses were submitted when hitting enter.  Add in a modifier that ensures that ctrl+enter is needed.
     if event.which == 17 && @is_ctrl==false
       @is_ctrl=true
-    else if @is_ctrl==true && event.which == 13 && !@list_view && Rubric.check_complete()
+    else if @is_ctrl==true && event.which == 13 && !@list_view && @rub.check_complete()
       @submit_and_get_next()
 
   keyup_handler: (event) =>
@@ -271,8 +271,8 @@ class @StaffGrading
 
   skip_and_get_next: () =>
     data =
-      score: Rubric.get_total_score()
-      rubric_scores: Rubric.get_score_list()
+      score: @rub.get_total_score()
+      rubric_scores: @rub.get_score_list()
       feedback: @feedback_area.val()
       submission_id: @submission_id
       location: @location
@@ -286,8 +286,8 @@ class @StaffGrading
 
   submit_and_get_next: () ->
     data =
-      score: Rubric.get_total_score()
-      rubric_scores: Rubric.get_score_list()
+      score: @rub.get_total_score()
+      rubric_scores: @rub.get_score_list()
       feedback: @feedback_area.val()
       submission_id: @submission_id
       location: @location