Add pagination to asset retrieval

and push sorting down to the query

cms/djangoapps/contentstore/views/assets.py

@@ -23,6 +23,7 @@ from .access import get_location_and_verify_access
 from util.json_request import JsonResponse
 import json
 from django.utils.translation import ugettext as _
+from pymongo import DESCENDING
 
 
 __all__ = ['asset_index', 'upload_asset']
@@ -30,11 +31,14 @@ __all__ = ['asset_index', 'upload_asset']
 
 @login_required
 @ensure_csrf_cookie
-def asset_index(request, org, course, name):
+def asset_index(request, org, course, name, start=None, maxresults=None):
     """
     Display an editable asset library
 
     org, course, name: Attributes of the Location for the item to edit
+
+    :param start: which index of the result list to start w/, used for paging results
+    :param maxresults: maximum results
     """
     location = get_location_and_verify_access(request, org, course, name)
 
@@ -47,10 +51,17 @@ def asset_index(request, org, course, name):
     course_module = modulestore().get_item(location)
 
     course_reference = StaticContent.compute_location(org, course, name)
-    assets = contentstore().get_all_content_for_course(course_reference)
-
-    # sort in reverse upload date order
-    assets = sorted(assets, key=lambda asset: asset['uploadDate'], reverse=True)
+    if maxresults is not None:
+        maxresults = int(maxresults)
+        start = int(start) if start else 0
+        assets = contentstore().get_all_content_for_course(
+            course_reference, start=start, maxresults=maxresults,
+            sort=[('uploadDate', DESCENDING)]
+        )
+    else:
+        assets = contentstore().get_all_content_for_course(
+            course_reference, sort=[('uploadDate', DESCENDING)]
+        )
 
     asset_json = []
     for asset in assets:

cms/urls.py

@@ -73,7 +73,7 @@ urlpatterns = ('',  # nopep8
     url(r'^edit_tabs/(?P<org>[^/]+)/(?P<course>[^/]+)/course/(?P<coursename>[^/]+)$',
         'contentstore.views.edit_tabs', name='edit_tabs'),
 
-    url(r'^(?P<org>[^/]+)/(?P<course>[^/]+)/assets/(?P<name>[^/]+)$',
+    url(r'^(?P<org>[^/]+)/(?P<course>[^/]+)/assets/(?P<name>[^/]+)(/start/(?P<start>\d+))?(/max/(?P<maxresults>\d+))?$',
         'contentstore.views.asset_index', name='asset_index'),
     url(r'^(?P<org>[^/]+)/(?P<course>[^/]+)/assets/(?P<name>[^/]+)/(?P<asset_id>.+)?.*$',
         'contentstore.views.assets.update_asset', name='update_asset'),

common/lib/xmodule/xmodule/contentstore/content.py

@@ -168,7 +168,7 @@ class ContentStore(object):
     def find(self, filename):
         raise NotImplementedError
 
-    def get_all_content_for_course(self, location):
+    def get_all_content_for_course(self, location, start=0, maxresults=-1, sort=None):
         '''
         Returns a list of all static assets for a course. The return format is a list of dictionary elements. Example:
 

common/lib/xmodule/xmodule/contentstore/mongo.py

@@ -130,10 +130,12 @@ class MongoContentStore(ContentStore):
     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, start=0, maxresults=-1, sort=None):
+        return self._get_all_content_for_course(
+            location, start=start, maxresults=maxresults, get_thumbnails=False, sort=sort
+        )
 
-    def _get_all_content_for_course(self, location, get_thumbnails=False):
+    def _get_all_content_for_course(self, location, get_thumbnails=False, start=0, maxresults=-1, sort=None):
         '''
         Returns a list of all static assets for a course. The return format is a list of dictionary elements. Example:
 
@@ -156,7 +158,13 @@ class MongoContentStore(ContentStore):
         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))
+        if maxresults > 0:
+            items = self.fs_files.find(
+                location_to_query(course_filter),
+                skip=start, limit=maxresults, sort=sort
+            )
+        else:
+            items = self.fs_files.find(location_to_query(course_filter), sort=sort)
         return list(items)
 
     def set_attr(self, location, attr, value=True):