Merge pull request #848 from MITx/feature/cas/lyla/asset-store-integration

Feature/cas/lyla/asset store integration
2012-10-11 08:59:50 -07:00
parent 6a7fb1d53b f06c67ef08
commit f010875750
9 changed files with 201 additions and 185 deletions
--- a/cms/djangoapps/contentstore/utils.py
+++ b/cms/djangoapps/contentstore/utils.py
@@ -74,3 +74,8 @@ def compute_unit_state(unit):
            return UnitState.private
    else:
        return UnitState.public
+
+
+def get_date_display(date):
+    print date, type(date)
+    return date.strftime("%d %B, %Y at %I:%M %p")
--- a/cms/djangoapps/contentstore/views.py
+++ b/cms/djangoapps/contentstore/views.py
@@ -1,3 +1,4 @@
+import traceback 
 from util.json_request import expect_json
 import exceptions
 import json
@@ -44,7 +45,7 @@ from cache_toolbox.core import set_cached_content, get_cached_content, del_cache
 from auth.authz import is_user_in_course_group_role, get_users_in_course_group_by_role
 from auth.authz import get_user_by_email, add_user_to_course_group, remove_user_from_course_group
 from auth.authz import INSTRUCTOR_ROLE_NAME, STAFF_ROLE_NAME
-from .utils import get_course_location_for_item, get_lms_link_for_item, compute_unit_state
+from .utils import get_course_location_for_item, get_lms_link_for_item, compute_unit_state, get_date_display

 from xmodule.templates import all_templates

@@ -618,7 +619,7 @@ def upload_asset(request, org, course, coursename):
    if not has_access(request.user, location):
        return HttpResponseForbidden()
    
-    # Does the course actually exist?!?
+    # Does the course actually exist?!? Get anything from it to prove its existance
    
    try:
        item = modulestore().get_item(location)
@@ -635,23 +636,11 @@ def upload_asset(request, org, course, coursename):
    mime_type = request.FILES['file'].content_type
    filedata = request.FILES['file'].read()

-    file_location = StaticContent.compute_location(org, course, name)
+    thumbnail_file_location = None

-    content = StaticContent(file_location, name, mime_type, filedata)
-
-    # first commit to the DB
-    contentstore().save(content)
-
-    # then remove the cache so we're not serving up stale content
-    # NOTE: we're not re-populating the cache here as the DB owns the last-modified timestamp
-    # which is used when serving up static content. This integrity is needed for
-    # browser-side caching support. We *could* re-fetch the saved content so that we have the
-    # timestamp populated, but we might as well wait for the first real request to come in
-    # to re-populate the cache.
-    del_cached_content(content.location)
-
-    # if we're uploading an image, then let's generate a thumbnail so that we can
-    # serve it up when needed without having to rescale on the fly
+    # if the upload asset is an image, we can generate a thumbnail from it
+    # let's do so now, so that we have the thumbnail location which we need 
+    # so that the asset can point to it
    if mime_type.split('/')[0] == 'image':
        try:
            # not sure if this is necessary, but let's rewind the stream just in case
@@ -673,24 +662,45 @@ def upload_asset(request, org, course, coursename):
            thumbnail_file.seek(0)
        
            # use a naming convention to associate originals with the thumbnail
-            thumbnail_name = content.generate_thumbnail_name()
+            thumbnail_name = StaticContent.generate_thumbnail_name(name)

            # then just store this thumbnail as any other piece of content
            thumbnail_file_location = StaticContent.compute_location(org, course, 
-                                                                              thumbnail_name)
+                                                                              thumbnail_name, is_thumbnail=True)
            thumbnail_content = StaticContent(thumbnail_file_location, thumbnail_name, 
                                              'image/jpeg', thumbnail_file)
            contentstore().save(thumbnail_content)
-
+            
            # remove any cached content at this location, as thumbnails are treated just like any
            # other bit of static content
            del_cached_content(thumbnail_content.location)
+
+            # not sure if this is necessary, but let's rewind the stream just in case
+            request.FILES['file'].seek(0)
        except:
            # catch, log, and continue as thumbnails are not a hard requirement
            logging.error('Failed to generate thumbnail for {0}. Continuing...'.format(name))
+            thumbnail_file_location = None


-    return HttpResponse('Upload completed')
+    file_location = StaticContent.compute_location(org, course, name)
+
+    # create a StaticContent entity and point to the thumbnail
+    content = StaticContent(file_location, name, mime_type, filedata, thumbnail_location = thumbnail_file_location)
+
+    # first commit to the DB
+    contentstore().save(content)
+
+    # then remove the cache so we're not serving up stale content
+    # NOTE: we're not re-populating the cache here as the DB owns the last-modified timestamp
+    # which is used when serving up static content. This integrity is needed for
+    # browser-side caching support. We *could* re-fetch the saved content so that we have the
+    # timestamp populated, but we might as well wait for the first real request to come in
+    # to re-populate the cache.
+    del_cached_content(content.location)
+    response = HttpResponse('Upload completed')
+    response['asset_url'] = StaticContent.get_url_path_from_location(file_location)
+    return response

 '''
 This view will return all CMS users who are editors for the specified course
@@ -772,23 +782,69 @@ def remove_user(request, location):

    return create_json_response()

-@login_required
-@ensure_csrf_cookie
-def asset_index(request, location):
-    return render_to_response('asset_index.html',{})

 # points to the temporary course landing page with log in and sign up
 def landing(request, org, course, coursename):
    return render_to_response('temp-course-landing.html', {})

+
 def static_pages(request, org, course, coursename):
    return render_to_response('static-pages.html', {})

+
 def edit_static(request, org, course, coursename):
    return render_to_response('edit-static-page.html', {})

+
 def not_found(request):
    return render_to_response('error.html', {'error': '404'})

+
 def server_error(request):
-    return render_to_response('error.html', {'error': '500'})
+    return render_to_response('error.html', {'error': '500'})
+
+
+@login_required
+@ensure_csrf_cookie
+def asset_index(request, org, course, name):
+    """
+    Display an editable asset library
+
+    org, course, name: Attributes of the Location for the item to edit
+    """
+    location = ['i4x', org, course, 'course', name]
+    
+    # check that logged in user has permissions to this item
+    if not has_access(request.user, location):
+        raise PermissionDenied()
+
+    upload_asset_callback_url = reverse('upload_asset', kwargs = {
+            'org' : org,
+            'course' : course,
+            'coursename' : name
+            })
+    
+    course_reference = StaticContent.compute_location(org, course, name)
+    assets = contentstore().get_all_content_for_course(course_reference)
+    thumbnails = contentstore().get_all_content_thumbnails_for_course(course_reference)
+    asset_display = []
+    for asset in assets:
+        id = asset['_id']
+        display_info = {}
+        display_info['displayname'] = asset['displayname']
+        display_info['uploadDate'] = get_date_display(asset['uploadDate'])
+        
+        asset_location = StaticContent.compute_location(id['org'], id['course'], id['name'])
+        display_info['url'] = StaticContent.get_url_path_from_location(asset_location)
+        
+        # note, due to the schema change we may not have a 'thumbnail_location' in the result set
+        thumbnail_location = Location(asset.get('thumbnail_location', None))
+
+        display_info['thumb_url'] = StaticContent.get_url_path_from_location(thumbnail_location)
+        
+        asset_display.append(display_info)
+
+    return render_to_response('asset_index.html', {
+        'assets': asset_display,
+        'upload_asset_callback_url': upload_asset_callback_url
+    })
--- a/cms/static/js/base.js
+++ b/cms/static/js/base.js
@@ -23,6 +23,10 @@ $(document).ready(function() {
    $modalCover.bind('click', hideHistoryModal);
    $('.assets .upload-button').bind('click', showUploadModal);
    $('.upload-modal .close-button').bind('click', hideModal);
+
+    $('a.show-xml').toggle(showEmbeddableXML, hideEmbeddableXML);
+
+    $('a.copy-button').toggle(showEmbeddableXML, hideEmbeddableXML);
    $('.unit .item-actions .delete-button').bind('click', deleteUnit);
    $('.new-unit-item').bind('click', createNewUnit);
    $('.save-subsection').bind('click', saveSubsection);
@@ -72,6 +76,17 @@ function removePolicyMetadata(e) {
        _parent_el.remove();
    else
        _parent_el.appendTo("#policy-to-delete");
+
+function showEmbeddableXML(e) {
+    $ceiling = $(this).parents('tr');
+    if ($ceiling.length === 0) $ceiling = $(this).parents('.upload-modal');
+    $ceiling.find('.embeddable-xml').html('&lt;img src="'+$(this).attr('href')+'"/&gt;');
+}
+function hideEmbeddableXML(e) {
+    $ceiling = $(this).parents('tr');
+    console.log($ceiling.length)
+    if ($ceiling.length === 0) $ceiling = $(this).parents('.upload-modal');
+    $ceiling.find('.embeddable-xml').html("");
 }


@@ -233,20 +248,40 @@ function showFileSelectionMenu(e) {
 function startUpload(e) {
    $('.upload-modal h1').html('Uploading…');
    $('.upload-modal .file-name').html($('.file-input').val());
+    $('.upload-modal .file-chooser').ajaxSubmit({
+        beforeSend: resetUploadBar,
+        uploadProgress: showUploadFeedback,
+        complete: displayFinishedUpload
+    });
    $('.upload-modal .choose-file-button').hide();
    $('.upload-modal .progress-bar').removeClass('loaded').show();
-    $('.upload-modal .progress-fill').html('').css('width', '0').animate({
-        'width': '100%'
-    }, 1500);
-    setTimeout(markAsLoaded, 1500);
+}
+
+function resetUploadBar(){
+    var percentVal = '0%';
+    $('.upload-modal .progress-fill').width(percentVal)
+    $('.upload-modal .progress-fill').html(percentVal);
+}
+
+function showUploadFeedback(event, position, total, percentComplete) {
+    var percentVal = percentComplete + '%';
+    $('.upload-modal .progress-fill').width(percentVal);
+    $('.upload-modal .progress-fill').html(percentVal);
+}
+
+function displayFinishedUpload(xhr) {
+    if(xhr.status = 200){
+        markAsLoaded();
+    }
+    $('.upload-modal .copy-button').attr('href', xhr.getResponseHeader('asset_url'));
+    $('.upload-modal .progress-fill').html(xhr.responseText);
+    $('.upload-modal .choose-file-button').html('Load Another File').show();
 }

 function markAsLoaded() {
    $('.upload-modal .copy-button').css('display', 'inline-block');
    $('.upload-modal .progress-bar').addClass('loaded');
-    $('.upload-modal .progress-fill').html('loaded successfully');
-    $('.upload-modal .choose-file-button').html('Load Another File').show();
-}
+}    

 function hideModal(e) {
    e.preventDefault();
--- a/cms/static/sass/_assets.scss
+++ b/cms/static/sass/_assets.scss
@@ -86,6 +86,9 @@
      }
    }
  }
+    .show-xml {
+    @include blue-button;
+  }
 }

 .upload-modal {
--- a/cms/templates/asset_index.html
+++ b/cms/templates/asset_index.html
@@ -9,7 +9,8 @@
    <div class="inner-wrapper">
      <h1>Asset Library</h1>
      <div class="page-actions">
-        <a href="#" class="upload-button">Upload New File</a><input type="text" class="asset-search-input search wip-box" placeholder="search assets" />
+        <a href="#" class="upload-button">Upload New File</a>
+	      <input type="text" class="asset-search-input search wip-box" placeholder="search assets" />
      </div>
      <article class="asset-library">
        <table>
@@ -22,149 +23,26 @@
            </tr>
          </thead>
          <tbody>
+          % for asset in assets:
            <tr>
              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/3185/screenshots/149571/picture_39.png"></div>
+                <div class="thumb"><img src="${asset['thumb_url']}"></div>
              </td>
              <td class="name-col">
-                <a href="#" class="filename">raygun-1.jpg</a>
+                <a href="${asset['url']}" class="filename">${asset['displayname']}</a>
+                <div class="embeddable-xml"></div>
              </td>
              <td class="date-col">
-                10/2/2012
+                ${asset['uploadDate']}
              </td>
              <td class="embed-col">
-                <a href="#">copy</a>
-              </td>
-            </tr>
-            <tr>
-              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/4573/screenshots/157708/final.png"></div>
-              </td>
-              <td class="name-col">
-                <a href="#" class="filename">raygun-2.jpg</a>
-              </td>
-              <td class="date-col">
-                10/2/2012
-              </td>
-              <td class="embed-col">
-                <a href="#">copy</a>
-              </td>
-            </tr>
-            <tr>
-              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/15101/screenshots/228625/star_wars_lightsbaer_2.jpg"></div>
-              </td>
-              <td class="name-col">
-                <a href="#" class="filename">raygun-2.jpg</a>
-              </td>
-              <td class="date-col">
-                10/2/2012
-              </td>
-              <td class="embed-col">
-                <a href="#">copy</a>
-              </td>
-            </tr>
-            <tr>
-              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/3185/screenshots/149571/picture_39.png"></div>
-              </td>
-              <td class="name-col">
-                <a href="#" class="filename">raygun-1.jpg</a>
-              </td>
-              <td class="date-col">
-                10/2/2012
-              </td>
-              <td class="embed-col">
-                <a href="#">copy</a>
-              </td>
-            </tr>
-            <tr>
-              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/4573/screenshots/157708/final.png"></div>
-              </td>
-              <td class="name-col">
-                <a href="#" class="filename">raygun-2.jpg</a>
-              </td>
-              <td class="date-col">
-                10/2/2012
-              </td>
-              <td class="embed-col">
-                <a href="#">copy</a>
-              </td>
-            </tr>
-            <tr>
-              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/15101/screenshots/228625/star_wars_lightsbaer_2.jpg"></div>
-              </td>
-              <td class="name-col">
-                <a href="#" class="filename">raygun-2.jpg</a>
-              </td>
-              <td class="date-col">
-                10/2/2012
-              </td>
-              <td class="embed-col">
-                <a href="#">copy</a>
-              </td>
-            </tr>
-            <tr>
-              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/3185/screenshots/149571/picture_39.png"></div>
-              </td>
-              <td class="name-col">
-                <a href="#" class="filename">raygun-1.jpg</a>
-              </td>
-              <td class="date-col">
-                10/2/2012
-              </td>
-              <td class="embed-col">
-                <a href="#">copy</a>
-              </td>
-            </tr>
-            <tr>
-              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/4573/screenshots/157708/final.png"></div>
-              </td>
-              <td class="name-col">
-                <a href="#" class="filename">raygun-2.jpg</a>
-              </td>
-              <td class="date-col">
-                10/2/2012
-              </td>
-              <td class="embed-col">
-                <a href="#">copy</a>
-              </td>
-            </tr>
-            <tr>
-              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/15101/screenshots/228625/star_wars_lightsbaer_2.jpg"></div>
-              </td>
-              <td class="name-col">
-                <a href="#" class="filename">raygun-2.jpg</a>
-              </td>
-              <td class="date-col">
-                10/2/2012
-              </td>
-              <td class="embed-col">
-                <a href="#">copy</a>
-              </td>
-            </tr>
-            <tr>
-              <td class="thumb-col">
-                <div class="thumb"><img src="http://dribbble.s3.amazonaws.com/users/3185/screenshots/149571/picture_39.png"></div>
-              </td>
-              <td class="name-col">
-                <a href="#" class="filename">raygun-1.jpg</a>
-              </td>
-              <td class="date-col">
-                10/2/2012
-              </td>
-              <td class="embed-col">
-                <a href="#">copy</a>
+                <a class="show-xml" href="${asset['url']}">XML</a>
              </td>
            </tr>
+          % endfor
          </tbody>
        </table>
-        <nav class="pagination">
+        <nav class="pagination wip-box">
          Page: 
          <ol class="pages">
            <li>1</li>
@@ -187,14 +65,17 @@
 			<div class="progress-bar">
 				<div class="progress-fill"></div>
 			</div>
-			<a href="#" class="copy-button">Copy Embed Link</a>
-			<div class="file-chooser">
+      <div class="embeddable-xml"></div>
+      <a href="#" class="copy-button">Show Embeddable XML</a>
+			<form class="file-chooser" action="${upload_asset_callback_url}"
+                                method="post" enctype="multipart/form-data">
 				<a href="#" class="choose-file-button">Choose File</a>
-				<input type="file" class="file-input">
-			</div>
+				<input type="file" class="file-input" name="file">
+			</form>
 		</div>
 	</div>

 	<div class="modal-cover"></div>

+
 </%block>
--- a/cms/templates/base.html
+++ b/cms/templates/base.html
@@ -33,6 +33,7 @@
    <script src="${static.url('js/vendor/jquery.cookie.js')}"></script>
    <script src="${static.url('js/vendor/jquery.leanModal.min.js')}"></script>
    <script src="${static.url('js/vendor/jquery.tablednd.js')}"></script>
+    <script src="http://malsup.github.com/jquery.form.js"></script>
    <script type="text/javascript">
      document.write('\x3Cscript type="text/javascript" src="' +
          document.location.protocol + '//www.youtube.com/player_api">\x3C/script>');
--- a/cms/urls.py
+++ b/cms/urls.py
@@ -30,16 +30,17 @@ urlpatterns = ('',
        'contentstore.views.remove_user', name='remove_user'),
    url(r'^(?P<org>[^/]+)/(?P<course>[^/]+)/course/(?P<name>[^/]+)/remove_user$',
        'contentstore.views.remove_user', name='remove_user'),
-    url(r'^assets/(?P<location>.*?)$', 'contentstore.views.asset_index', name='asset_index'),
    url(r'^pages/(?P<org>[^/]+)/(?P<course>[^/]+)/course/(?P<coursename>[^/]+)$', 'contentstore.views.static_pages', name='static_pages'),
    url(r'^edit_static/(?P<org>[^/]+)/(?P<course>[^/]+)/course/(?P<coursename>[^/]+)$', 'contentstore.views.edit_static', name='edit_static'),
+    url(r'^(?P<org>[^/]+)/(?P<course>[^/]+)/assets/(?P<name>[^/]+)$', 'contentstore.views.asset_index', name='asset_index'),

    # temporary landing page for a course
    url(r'^landing/(?P<org>[^/]+)/(?P<course>[^/]+)/course/(?P<coursename>[^/]+)$', 'contentstore.views.landing', name='landing'),

    url(r'^not_found$', 'contentstore.views.not_found', name='not_found'),
-    url(r'^server_error$', 'contentstore.views.server_error', name='server_error')
+    url(r'^server_error$', 'contentstore.views.server_error', name='server_error'),

+    url(r'^(?P<org>[^/]+)/(?P<course>[^/]+)/assets/(?P<name>[^/]+)$', 'contentstore.views.asset_index', name='asset_index'),
 )

 # User creation and updating views
--- a/common/lib/xmodule/xmodule/contentstore/content.py
+++ b/common/lib/xmodule/xmodule/contentstore/content.py
@@ -1,30 +1,32 @@
 XASSET_LOCATION_TAG = 'c4x'
 XASSET_SRCREF_PREFIX = 'xasset:'

-XASSET_THUMBNAIL_TAIL_NAME = '.thumbnail.jpg'
+XASSET_THUMBNAIL_TAIL_NAME = '.jpg'

 import os
 import logging
 from xmodule.modulestore import Location

 class StaticContent(object):
-    def __init__(self, loc, name, content_type, data, last_modified_at=None):
+    def __init__(self, loc, name, content_type, data, last_modified_at=None, thumbnail_location=None):
        self.location = loc
        self.name = name #a display string which can be edited, and thus not part of the location which needs to be fixed
        self.content_type = content_type
        self.data = data
        self.last_modified_at = last_modified_at
+        self.thumbnail_location = thumbnail_location

    @property
    def is_thumbnail(self):
-        return self.name.endswith(XASSET_THUMBNAIL_TAIL_NAME)
-
-    def generate_thumbnail_name(self):
-        return ('{0}'+XASSET_THUMBNAIL_TAIL_NAME).format(os.path.splitext(self.name)[0])
+        return self.location.category == 'thumbnail'

    @staticmethod
-    def compute_location(org, course, name, revision=None):
-        return Location([XASSET_LOCATION_TAG, org, course, 'asset', name, revision])
+    def generate_thumbnail_name(original_name):
+        return ('{0}'+XASSET_THUMBNAIL_TAIL_NAME).format(os.path.splitext(original_name)[0])
+
+    @staticmethod
+    def compute_location(org, course, name, revision=None, is_thumbnail=False):
+        return Location([XASSET_LOCATION_TAG, org, course, 'asset' if not is_thumbnail else 'thumbnail', Location.clean(name), revision])

    def get_id(self):
        return StaticContent.get_id_from_location(self.location)
@@ -34,7 +36,10 @@ class StaticContent(object):
    
    @staticmethod
    def get_url_path_from_location(location):
-        return "/{tag}/{org}/{course}/{category}/{name}".format(**location.dict())
+        if location is not None:
+            return "/{tag}/{org}/{course}/{category}/{name}".format(**location.dict())
+        else:
+            return None

    @staticmethod
    def get_id_from_location(location):
@@ -65,4 +70,23 @@ class ContentStore(object):
        raise NotImplementedError

    def get_all_content_for_course(self, location):
+        '''
+        Returns a list of all static assets for a course. The return format is a list of dictionary elements. Example:
+
+            [
+
+            {u'displayname': u'profile.jpg', u'chunkSize': 262144, u'length': 85374, 
+            u'uploadDate': datetime.datetime(2012, 10, 3, 5, 41, 54, 183000), u'contentType': u'image/jpeg', 
+            u'_id': {u'category': u'asset', u'name': u'profile.jpg', u'course': u'6.002x', u'tag': u'c4x', 
+            u'org': u'MITx', u'revision': None}, u'md5': u'36dc53519d4b735eb6beba51cd686a0e'}, 
+
+            {u'displayname': u'profile.thumbnail.jpg', u'chunkSize': 262144, u'length': 4073, 
+            u'uploadDate': datetime.datetime(2012, 10, 3, 5, 41, 54, 196000), u'contentType': u'image/jpeg', 
+            u'_id': {u'category': u'asset', u'name': u'profile.thumbnail.jpg', u'course': u'6.002x', u'tag': u'c4x', 
+            u'org': u'MITx', u'revision': None}, u'md5': u'ff1532598830e3feac91c2449eaa60d6'},
+
+            ....
+
+            ]
+        '''
        raise NotImplementedError
--- a/common/lib/xmodule/xmodule/contentstore/mongo.py
+++ b/common/lib/xmodule/xmodule/contentstore/mongo.py
@@ -28,7 +28,9 @@ class MongoContentStore(ContentStore):
        if self.fs.exists({"_id" : id}):
            self.fs.delete(id)

-        with self.fs.new_file(_id = id, filename=content.get_url_path(), content_type=content.content_type, displayname=content.name) as fp:
+        with self.fs.new_file(_id = id, filename=content.get_url_path(), content_type=content.content_type, 
+            displayname=content.name, thumbnail_location=content.thumbnail_location) as fp:
+
            fp.write(content.data)
        
        return content
@@ -38,11 +40,18 @@ class MongoContentStore(ContentStore):
        id = StaticContent.get_id_from_location(location)
        try:
            with self.fs.get(id) as fp:
-                return StaticContent(location, fp.displayname, fp.content_type, fp.read(), fp.uploadDate)
+                return StaticContent(location, fp.displayname, fp.content_type, fp.read(), 
+                    fp.uploadDate, thumbnail_location = fp.thumbnail_location if 'thumbnail_location' in fp else None)
        except NoFile:
            raise NotFoundError()

-    def get_all_content_info_for_course(self, location):
+    def get_all_content_thumbnails_for_course(self, location):
+        return self._get_all_content_for_course(location, get_thumbnails = True)
+
+    def get_all_content_for_course(self, location):
+        return self._get_all_content_for_course(location, get_thumbnails = False)
+
+    def _get_all_content_for_course(self, location, get_thumbnails = False):
        '''
        Returns a list of all static assets for a course. The return format is a list of dictionary elements. Example:

@@ -62,7 +71,8 @@ class MongoContentStore(ContentStore):

            ]
        '''
-        course_filter = Location(XASSET_LOCATION_TAG, category="asset",course=location.course,org=location.org)
+        course_filter = Location(XASSET_LOCATION_TAG, category="asset" if not get_thumbnails else "thumbnail",
+            course=location.course,org=location.org)
        # 'borrow' the function 'location_to_query' from the Mongo modulestore implementation
        items = self.fs_files.find(location_to_query(course_filter))
        return list(items)