Working prototype of crowdsourced hinting module.

Conflicts:
	common/static/coffee/src/logger.coffee

common/lib/xmodule/setup.py

@@ -55,6 +55,7 @@ setup(
             "word_cloud = xmodule.word_cloud_module:WordCloudDescriptor",
             "hidden = xmodule.hidden_module:HiddenDescriptor",
             "raw = xmodule.raw_module:RawDescriptor",
+            "crowdsource_hinter = xmodule.crowdsource_hinter:CrowdsourceHinterDescriptor",
         ],
         'console_scripts': [
             'xmodule_assets = xmodule.static_content:main',

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

@@ -223,6 +223,7 @@ class @Problem
             @el.removeClass 'showed'
         else
           @gentle_alert response.success
+      Logger.log 'problem_graded', [@answers, response.contents], @url
 
   reset: =>
     Logger.log 'problem_reset', @answers

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

+class @Hinter
+
+  constructor: (element) ->
+    @el = $(element).find('.crowdsource-wrapper')
+    @url = @el.data('url')
+    Logger.listen('problem_graded', @el.data('child-url'), @capture_problem)
+    # The line below will eventually be generated by Python.
+    @render()
+
+  capture_problem: (event_type, data, element) =>
+    # After a problem gets graded, we get the info here.
+    # We want to send this info to the server in another AJAX
+    # request.
+    answers = data[0]
+    response = data[1]
+    if response.search(/class="correct "/) == -1
+      # Incorrect.  Get hints.
+      $.postWithPrefix "#{@url}/get_hint", answers, (response) =>
+        @render(response.contents)
+    else
+      # Correct.  Get feedback from students.
+      $.postWithPrefix "#{@url}/get_feedback", answers, (response) =>
+        @render(response.contents)
+
+  $: (selector) ->
+    $(selector, @el)
+
+  bind: =>
+    window.update_schematics()
+    @$('input.vote').click @vote
+    @$('#feedback-select').change @feedback_ui_change
+    @$('input.submit-hint').click @submit_hint
+
+
+  vote: (eventObj) =>
+    target = @$(eventObj.currentTarget)
+    post_json = {'answer': target.data('answer'), 'hint': target.data('hintno')}
+    $.postWithPrefix "#{@url}/vote", post_json, (response) =>
+      @render(response.contents)
+
+  submit_hint: (eventObj) =>
+    target = @$(eventObj.currentTarget)
+    textarea_id = '#custom-hint-' + target.data('answer')
+    console.debug(textarea_id)
+    post_json = {'answer': target.data('answer'), 'hint': @$(textarea_id).val()}
+    $.postWithPrefix "#{@url}/submit_hint",post_json, (response) =>
+      @render(response.contents)
+
+  feedback_ui_change: =>
+    # Make all of the previous-answer divs hidden.
+    @$('.previous-answer').css('display', 'none')
+    # But, now find the selected div, and make it visible.
+    selector = '#previous-answer-' + @$('#feedback-select option:selected').attr('value')
+    @$(selector).css('display', 'inline')
+
+
+  render: (content) ->
+    if content
+      @el.html(content)
+      JavascriptLoader.executeModuleScripts @el, () =>
+        @bind()
+      @$('#previous-answer-0').css('display', 'inline')
\ No newline at end of file

common/static/coffee/src/logger.coffee

 class @Logger
+
   # events we want sent to Segment.io for tracking
   SEGMENT_IO_WHITELIST = ["seq_goto", "seq_next", "seq_prev", "problem_check", "problem_reset", "problem_show", "problem_save"]
 
-  @log: (event_type, data) ->
+  # listeners[event_type][element] -> list of callbacks
+  listeners = {}
+  @log: (event_type, data, element = null) ->
     # Segment.io event tracking
     if event_type in SEGMENT_IO_WHITELIST
       # to avoid changing the format of data sent to our servers, we only massage it here
@@ -11,11 +14,36 @@ class @Logger
       else
         analytics.track event_type, data
 
+    # Check to see if we're listening for the event type.
+    if event_type of listeners
+      # Cool.  Do the elements also match?
+      # null element in the listener dictionary means any element will do.
+      # null element in the @log call means we don't know the element name.
+      if null of listeners[event_type]
+        # Make the callbacks.
+        for callback in listeners[event_type][null]
+          callback(event_type, data, element)
+      else if element of listeners[event_type]
+        for callback in listeners[event_type][element]
+          callback(event_type, data, element)
+
+    # Regardless of whether any callbacks were made, log this event.
     $.getWithPrefix '/event',
       event_type: event_type
       event: JSON.stringify(data)
       page: window.location.href
 
+  @listen: (event_type, element, callback) ->
+    # Add a listener.  If you want any element to trigger this listener,
+    # do element = null
+    if event_type not of listeners
+      listeners[event_type] = {}
+    if element not of listeners[event_type]
+      listeners[event_type][element] = [callback]
+    else
+      listeners[event_type][element].push callback
+
+
   @bind: ->
     window.onunload = ->
       $.ajaxWithPrefix