Make editing work, building towards drag/drop saving

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

@@ -1,4 +1,4 @@
-class @InlineDiscussion
+class @InlineDiscussion extends XModule.Descriptor
   constructor: (element) ->
     @el = $(element).find('.discussion-module')
     @view = new DiscussionModuleView(el: @el)

common/lib/xmodule/xmodule/js/src/raw/edit/json.coffee

@@ -1,7 +1,8 @@
-class @JSONEditingDescriptor
+class @JSONEditingDescriptor extends XModule.Descriptor
   constructor: (@element) ->
     @edit_box = CodeMirror.fromTextArea($(".edit-box", @element)[0], {
       mode: { name: "javascript", json: true }
     })
 
-  save: -> JSON.parse @edit_box.getValue()
+  save: ->
+    data: JSON.parse @edit_box.getValue()

common/lib/xmodule/xmodule/js/src/raw/edit/xml.coffee

@@ -1,7 +1,8 @@
-class @XMLEditingDescriptor
+class @XMLEditingDescriptor extends XModule.Descriptor
   constructor: (@element) ->
     @edit_box = CodeMirror.fromTextArea($(".edit-box", @element)[0], {
       mode: "xml"
     })
 
-  save: -> @edit_box.getValue()
+  save: ->
+    data: @edit_box.getValue()

common/lib/xmodule/xmodule/js/src/sequence/edit.coffee

@@ -1,4 +1,4 @@
-class @SequenceDescriptor
+class @SequenceDescriptor extends XModule.Descriptor
   constructor: (@element) ->
     @$tabs = $(@element).find("#sequence-list")
     @$tabs.sortable()

common/lib/xmodule/xmodule/js/src/vertical/edit.coffee

@@ -1,4 +1,4 @@
-class @VerticalDescriptor
+class @VerticalDescriptor extends XModule.Descriptor
   constructor: (@element) ->
     @$items = $(@element).find(".vert-mod")
     @$items.sortable()

common/lib/xmodule/xmodule/seq_module.py

@@ -86,6 +86,7 @@ class SequenceModule(XModule):
                 'progress_status': Progress.to_js_status_str(progress),
                 'progress_detail': Progress.to_js_detail_str(progress),
                 'type': child.get_icon_class(),
+                'id': child.id,
             }
             if childinfo['title']=='':
                 childinfo['title'] = child.metadata.get('display_name','')

common/static/coffee/src/xmodule.coffee

@@ -10,8 +10,13 @@
       return
 
     try
-      $(element).data('module', new window[moduleType](element))
-      $(document).trigger('XModule.loaded', [element])
+      module = new window[moduleType](element)
+      if $(element).hasClass('xmodule_edit')
+        $(document).trigger('XModule.loaded.edit', [element, module])
+
+      if $(element).hasClass('xmodule_display')
+        $(document).trigger('XModule.loaded.display', [element, module])
+
     catch error
       console.error "Unable to load #{moduleType}: #{error.message}" if console
 
@@ -29,3 +34,40 @@
       modules = $(selector)
 
     modules.each (idx, element) -> XModule.loadModule element
+
+class @XModule.Descriptor
+
+  callbacks: []
+
+  ###
+  Register a callback method to be called when the state of this
+  descriptor is updated. The callback will be passed the results
+  of calling the save method on this descriptor.
+  ###
+  onUpdate: (callback) ->
+    @callbacks.push(callback)
+
+  ###
+  Notify registered callbacks that the state of this descriptor has changed
+  ###
+  update: =>
+    data = @save()
+    callback(data) for callback in @callbacks
+
+  ###
+  Bind the module to an element. This may be called multiple times,
+  if the element content has changed and so the module needs to be rebound
+
+  @method: constructor
+  @param {html element} the .xmodule_edit section containing all of the descriptor content
+  ###
+  constructor: (@element) -> return
+
+  ###
+  Return the current state of the descriptor (to be written to the module store)
+
+  @method: save
+  @returns {object} An object containing children and data attributes (both optional).
+                    The contents of the attributes will be saved to the server
+  ###
+  save: -> return {}