Standardize how JS XModules are instantiated

cms/djangoapps/contentstore/views.py

@@ -14,7 +14,7 @@ from static_replace import replace_urls
 
 from mitxmako.shortcuts import render_to_response, render_to_string
 from xmodule.modulestore.django import modulestore
-from xmodule_modifiers import replace_static_urls
+from xmodule_modifiers import replace_static_urls, wrap_xmodule
 
 
 # ==== Public views ==================================================
@@ -97,6 +97,7 @@ def edit_item(request):
         raise Http404  # TODO (vshnayder): better error
 
     item = modulestore().get_item(item_location)
+    item.get_html = wrap_xmodule(item.get_html, item, "xmodule_edit.html")
     return render_to_response('unit.html', {
         'contents': item.get_html(),
         'js_module': item.js_module_name,
@@ -181,7 +182,10 @@ def load_sample_module(descriptor, instance_state, shared_state):
     """
     system = sample_module_system(descriptor)
     module = descriptor.xmodule_constructor(system)(instance_state, shared_state)
-    module.get_html = replace_static_urls(module.get_html, module.metadata['data_dir'])
+    module.get_html = replace_static_urls(
+        wrap_xmodule(module.get_html, module, "xmodule_display.html"),
+        module.metadata['data_dir']
+    )
 
     return module
 

cms/static/coffee/src/models/module.coffee

@@ -4,20 +4,7 @@ class CMS.Models.Module extends Backbone.Model
     data: ''
 
   loadModule: (element) ->
-    moduleType = @get('type')
-
-    try
-      @module = if moduleType? then new window[moduleType](element) else null
-    catch error
-      console.error "Unable to load #{moduleType}: #{error.message}" if console
-
-  loadPreview: (element) ->
-    previewType = @get('previewType')
-
-    try
-      @previewModule = if previewType? then new window[previewType](element) else null
-    catch error
-      console.error "Unable to load #{previewType}: #{error.message}" if console
+    @module = XModule.loadModule($(element).find('.xmodule_edit'))
 
   editUrl: ->
     "/edit_item?#{$.param(id: @get('id'))}"

cms/static/coffee/src/views/module_edit.coffee

@@ -10,8 +10,9 @@ class CMS.Views.ModuleEdit extends Backbone.View
   initialize: ->
     @$el.load @model.editUrl(), =>
       @model.loadModule(@el)
-      @$el.find('.preview').children().each (idx, previewEl) =>
-          @model.loadPreview(previewEl)
+
+      # Load preview modules
+      XModule.loadModules('display')
 
   save: (event) ->
     event.preventDefault()

common/djangoapps/xmodule_modifiers.py

@@ -5,17 +5,38 @@ from static_replace import replace_urls
 from mitxmako.shortcuts import render_to_string
 
 
-def replace_static_urls(original, prefix):
+def wrap_xmodule(get_html, module, template):
+    """
+    Wraps the results of get_html in a standard <section> with identifying
+    data so that the appropriate javascript module can be loaded onto it.
+
+    get_html: An XModule.get_html method or an XModuleDescriptor.get_html method
+    module: An XModule
+    template: A template that takes the variables:
+        content: the results of get_html,
+        module_name: the js_module_name of the module
+    """
+
+    @wraps(get_html)
+    def _get_html():
+        return render_to_string(template, {
+            'content': get_html(),
+            'module_name': module.js_module_name
+        })
+    return _get_html
+
+
+def replace_static_urls(get_html, prefix):
     """
     Updates the supplied module with a new get_html function that wraps
     the old get_html function and substitutes urls of the form /static/...
     with urls that are /static/<prefix>/...
     """
 
-    @wraps(original)
-    def get_html():
-        return replace_urls(original(), staticfiles_prefix=prefix)
-    return get_html
+    @wraps(get_html)
+    def _get_html():
+        return replace_urls(get_html(), staticfiles_prefix=prefix)
+    return _get_html
 
 
 def grade_histogram(module_id):
@@ -40,15 +61,15 @@ def grade_histogram(module_id):
     return grades
 
 
-def add_histogram(original, module):
+def add_histogram(get_html, module):
     """
     Updates the supplied module with a new get_html function that wraps
     the output of the old get_html function with additional information
     for admin users only, including a histogram of student answers and the
     definition of the xmodule
     """
-    @wraps(original)
-    def get_html():
+    @wraps(get_html)
+    def _get_html():
         module_id = module.id
         histogram = grade_histogram(module_id)
         render_histogram = len(histogram) > 0
@@ -73,7 +94,7 @@ def add_histogram(original, module):
                          'edit_link': edit_link,
                          'histogram': json.dumps(histogram),
                          'render_histogram': render_histogram,
-                         'module_content': original()}
+                         'module_content': get_html()}
         return render_to_string("staff_problem_info.html", staff_context)
 
-    return get_html
+    return _get_html

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

 class @Problem
   constructor: (element) ->
-    @el = $(element)
+    @el = $(element).find('.problems-wrapper')
     @id = @el.data('problem-id')
     @element_id = @el.attr('id')
     @url = @el.data('url')

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

 class @Sequence
   constructor: (element) ->
-    (@id, @element_id, @elements, position) ->
-    @el = $(element)
+    @el = $(element).find('.sequence')
     @contents = @$('.seq_contents')
     @id = @el.data('id')
     @initProgress()
@@ -81,12 +80,12 @@ class @Sequence
 
       @mark_active new_position
       @$('#seq_content').html @contents.eq(new_position - 1).text()
+      XModule.loadModules('display', @$('#seq_content'))
 
       MathJax.Hub.Queue(["Typeset", MathJax.Hub])
       @position = new_position
       @toggleArrows()
       @hookUpProgressEvent()
-      @el.trigger 'contentChanged'
 
   goto: (event) =>
     event.preventDefault()

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

 class @Video
-  constructor: (@element) ->
-    @id = $(@element).attr('id').replace(/video_/, '')
-    @caption_data_dir = $(@element).data('caption-data-dir')
+  constructor: (element) ->
+    @el = $(element).find('.video')
+    @id = @el.attr('id').replace(/video_/, '')
+    @caption_data_dir = @el.data('caption-data-dir')
     window.player = null
     @el = $("#video_#{@id}")
-    @parseVideos $(@element).data('streams')
+    @parseVideos @el.data('streams')
     @fetchMetadata()
     @parseSpeed()
     $("#video_#{@id}").data('video', this).addClass('video-load-complete')

common/static/coffee/src/xmodule.coffee

+@XModule =
+    ###
+    Load a single module (either an edit module or a display module)
+    from the supplied element, which should have a data-type attribute
+    specifying the class to load
+    ###
+    loadModule: (element) ->
+        moduleType = $(element).data('type')
+        if moduleType == 'None'
+            return
+
+        try
+            new window[moduleType](element)
+        catch error
+            console.error "Unable to load #{moduleType}: #{error.message}" if console
+
+    ###
+    Load all modules on the page of the specified type.
+    If container is provided, only load modules inside that element
+    Type is one of 'display' or 'edit'
+    ###
+    loadModules: (type, container) ->
+        selector = ".xmodule_#{type}"
+
+        if container?
+            modules = $(container).find(selector)
+        else
+            modules = $(selector)
+
+        modules.each (idx, element) -> XModule.loadModule element

common/templates/xmodule_display.html

+<section class="xmodule_display" data-type="${module_name}">
+    ${content}
+</section>

common/templates/xmodule_edit.html

+<section class="xmodule_edit" data-type="${module_name}">
+    ${content}
+</section>

lms/djangoapps/courseware/module_render.py

@@ -11,7 +11,7 @@ from models import StudentModule, StudentModuleCache
 from static_replace import replace_urls
 from xmodule.exceptions import NotFoundError
 from xmodule.x_module import ModuleSystem
-from xmodule_modifiers import replace_static_urls, add_histogram
+from xmodule_modifiers import replace_static_urls, add_histogram, wrap_xmodule
 
 log = logging.getLogger("mitx.courseware")
 
@@ -161,7 +161,10 @@ def get_module(user, request, location, student_module_cache, position=None):
 
     module = descriptor.xmodule_constructor(system)(instance_state, shared_state)
 
-    module.get_html = replace_static_urls(module.get_html, module.metadata['data_dir'])
+    module.get_html = replace_static_urls(
+        wrap_xmodule(module.get_html, module, 'xmodule_display.html'),
+        module.metadata['data_dir']
+    )
 
     if settings.MITX_FEATURES.get('DISPLAY_HISTOGRAMS_TO_STAFF') and user.is_staff:
         module.get_html = add_histogram(module.get_html)

lms/static/coffee/src/courseware.coffee

@@ -5,19 +5,13 @@ class @Courseware
     Courseware.prefix = $("meta[name='path_prefix']").attr('content')
     new Navigation
     Logger.bind()
-    @bind()
     @render()
 
   @start: ->
     new Courseware
 
-  bind: ->
-    $('.course-content .sequence, .course-content .tab')
-      .bind 'contentChanged', @render
-
   render: ->
-    $('.course-content .video').each (idx, element) -> new Video element
-    $('.course-content .problems-wrapper').each (idx, element) -> new Problem element
+    XModule.loadModules('display')
     $('.course-content .histogram').each ->
       id = $(this).attr('id').replace(/histogram_/, '')
       new Histogram id, $(this).data('histogram')

lms/templates/seq_module.html

@@ -32,11 +32,3 @@
     </ul>
   </nav>
 </div>
-
-<%block name="js_extra">
-<script type="text/javascript">
-  $(function(){
-    new Sequence($("#sequence_${element_id}"));
-  });
-</script>
-</%block>