refactor StaticContent id scheme to be the same as moduledata. Also expose a new…

refactor StaticContent id scheme to be the same as moduledata. Also expose a new 'get all content for course' which will be needed to support a asset management page.

cms/djangoapps/contentstore/views.py

@@ -429,14 +429,13 @@ def clone_item(request):
 
     return HttpResponse(json.dumps({'id': dest_location.url()}))
 
-'''
-cdodge: this method allows for POST uploading of files into the course asset library, which will
-be supported by GridFS in MongoDB.
-'''
 #@login_required
 #@ensure_csrf_cookie
 def upload_asset(request, org, course, coursename):
-
+    '''
+    cdodge: this method allows for POST uploading of files into the course asset library, which will
+    be supported by GridFS in MongoDB.
+    '''
     if request.method != 'POST':
         # (cdodge) @todo: Is there a way to do a - say - 'raise Http400'?
         return HttpResponseBadRequest()
@@ -463,7 +462,7 @@ def upload_asset(request, org, course, coursename):
     mime_type = request.FILES['file'].content_type
     filedata = request.FILES['file'].read()
 
-    file_location = StaticContent.compute_location_filename(org, course, name)
+    file_location = StaticContent.compute_location(org, course, name)
 
     content = StaticContent(file_location, name, mime_type, filedata)
 
@@ -476,7 +475,7 @@ def upload_asset(request, org, course, coursename):
     # 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(file_location)
+    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
@@ -504,7 +503,7 @@ def upload_asset(request, org, course, coursename):
             #   <name_without_extention>.thumbnail.jpg
             thumbnail_name = os.path.splitext(name)[0] + '.thumbnail.jpg'
             # then just store this thumbnail as any other piece of content
-            thumbnail_file_location = StaticContent.compute_location_filename(org, course, 
+            thumbnail_file_location = StaticContent.compute_location(org, course, 
                                                                               thumbnail_name)
             thumbnail_content = StaticContent(thumbnail_file_location, thumbnail_name, 
                                               'image/jpeg', thumbnail_file)
@@ -512,7 +511,7 @@ def upload_asset(request, org, course, coursename):
 
             # remove any cached content at this location, as thumbnails are treated just like any
             # other bit of static content
-            del_cached_content(thumbnail_file_location)
+            del_cached_content(thumbnail_content.location)
         except:
             # catch, log, and continue as thumbnails are not a hard requirement
             logging.error('Failed to generate thumbnail for {0}. Continuing...'.format(name))

common/djangoapps/cache_toolbox/core.py

@@ -12,7 +12,7 @@ from django.core.cache import cache
 from django.db import DEFAULT_DB_ALIAS
 
 from . import app_settings
-
+from xmodule.contentstore.content import StaticContent
 
 def get_instance(model, instance_or_pk, timeout=None, using=None):
     """
@@ -108,14 +108,11 @@ def instance_key(model, instance_or_pk):
         getattr(instance_or_pk, 'pk', instance_or_pk),
     )
 
-def content_key(filename):
-    return 'content:%s' % (filename)
-
 def set_cached_content(content):
-    cache.set(content_key(content.filename), content)
+    cache.set(content.get_id(), content)
 
-def get_cached_content(filename):
-    return cache.get(content_key(filename))
+def get_cached_content(location):
+    return cache.get(StaticContent.get_id_from_location(location))
 
-def del_cached_content(filename):
-    cache.delete(content_key(filename))
+def del_cached_content(location):
+    cache.delete(StaticContent.get_id_from_location(location))

common/djangoapps/contentserver/middleware.py

@@ -12,14 +12,14 @@ from xmodule.exceptions import NotFoundError
 class StaticContentServer(object):
     def process_request(self, request):
         # look to see if the request is prefixed with 'c4x' tag
-        if request.path.startswith('/' + XASSET_LOCATION_TAG):
-
+        if request.path.startswith('/' + XASSET_LOCATION_TAG +'/'):
+            loc = StaticContent.get_location_from_path(request.path)
             # first look in our cache so we don't have to round-trip to the DB
-            content = get_cached_content(request.path)
+            content = get_cached_content(loc)
             if content is None:
                 # nope, not in cache, let's fetch from DB
                 try:
-                    content = contentstore().find(request.path)
+                    content = contentstore().find(loc)
                 except NotFoundError:
                     raise Http404
 

common/lib/xmodule/xmodule/capa_module.py

@@ -339,7 +339,10 @@ class CapaModule(XModule):
         # NOTE: rewrite_content_links is defined in XModule
         # This is a bit unfortunate and I'm sure we'll try to considate this into
         # a one step process.
-        html = rewrite_links(html, self.rewrite_content_links)
+        try:
+            html = rewrite_links(html, self.rewrite_content_links)
+        except:
+            logging.error('error rewriting links in {0}'.format(html))
 
         # now do the substitutions which are filesystem based, e.g. '/static/' prefixes
         return self.system.replace_urls(html, self.metadata['data_dir'])

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

 XASSET_LOCATION_TAG = 'c4x'
 XASSET_SRCREF_PREFIX = 'xasset:'
 
+import logging
+from xmodule.modulestore import Location
+
 class StaticContent(object):
-    def __init__(self, filename, name, content_type, data, last_modified_at=None):
-        self.filename = filename
-        self.name = name
+    def __init__(self, loc, name, content_type, data, last_modified_at=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
 
+
+    @staticmethod
+    def compute_location(org, course, name, revision=None):
+        return Location([XASSET_LOCATION_TAG, org, course, 'asset', name, revision])
+
+    def get_id(self):
+        return StaticContent.get_id_from_location(self.location)
+
+    def get_url_path(self):
+        return StaticContent.get_url_path_from_location(self.location)
+    
     @staticmethod
-    def compute_location_filename(org, course, name):
-        return '/{0}/{1}/{2}/asset/{3}'.format(XASSET_LOCATION_TAG, org, course, name)
+    def get_url_path_from_location(location):
+        return "/{tag}/{org}/{course}/{category}/{name}".format(**location.dict())
+
+    @staticmethod
+    def get_id_from_location(location):
+        return { 'tag':location.tag, 'org' : location.org, 'course' : location.course,
+                   'category' : location.category, 'name' : location.name, 
+                   'revision' : location.revision}
+    @staticmethod
+    def get_location_from_path(path):
+        # remove leading / character if it is there one
+        if path.startswith('/'):
+            path = path[1:]
+        
+        return Location(path.split('/'))
+
+    @staticmethod
+    def get_id_from_path(path):
+        return get_id_from_location(get_location_from_path(path))
+    
 
-'''
-Abstraction for all ContentStore providers (e.g. MongoDB)
-'''
 class ContentStore(object):
+    '''
+    Abstraction for all ContentStore providers (e.g. MongoDB)
+    '''
     def save(self, content):
         raise NotImplementedError
 
     def find(self, filename):
         raise NotImplementedError
 
-            
+    def get_all_content_for_course(self, location):
+        raise NotImplementedError

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

+from bson.son import SON
 from pymongo import Connection
 import gridfs
 from gridfs.errors import NoFile
 
+from xmodule.modulestore.mongo import location_to_query, Location
+from xmodule.contentstore.content import XASSET_LOCATION_TAG
+
 import sys
 import logging
 
@@ -14,19 +18,34 @@ class MongoContentStore(ContentStore):
         logging.debug( 'Using MongoDB for static content serving at host={0} db={1}'.format(host,db))
         _db = Connection(host=host, port=port)[db]
         self.fs = gridfs.GridFS(_db)
+        self.fs_files = _db["fs.files"] # the underlying collection GridFS uses
+
 
     def save(self, content):
-        with self.fs.new_file(filename=content.filename, content_type=content.content_type, displayname=content.name) as fp:
+        id = content.get_id()
+
+        # Seems like with the GridFS we can't update existing ID's we have to do a delete/add pair
+        if self.fs.exists({"_id" : id}):
+            self.fs.delete(id)
+
+        with self.fs.new_file(_id = id, content_type=content.content_type, displayname=content.name) as fp:
             fp.write(content.data)
             return content
         
     
-    def find(self, filename):
+    def find(self, location):
+        id = StaticContent.get_id_from_location(location)
         try:
-            with self.fs.get_last_version(filename) as fp:
-                return StaticContent(fp.filename, fp.displayname, fp.content_type, fp.read(), fp.uploadDate)
+            with self.fs.get(id) as fp:
+                return StaticContent(location, fp.displayname, fp.content_type, fp.read(), fp.uploadDate)
         except NoFile:
             raise NotFoundError()
 
+    def get_all_content_info_for_course(self, location):
+        course_filter = Location(XASSET_LOCATION_TAG, category="asset",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 items
+
 
         

common/lib/xmodule/xmodule/html_module.py

@@ -26,7 +26,13 @@ class HtmlModule(XModule):
     
     def get_html(self):
         # cdodge: perform link substitutions for any references to course static content (e.g. images)
-        return rewrite_links(self.html, self.rewrite_content_links)
+        _html = self.html
+        try:
+            _html = rewrite_links(_html, self.rewrite_content_links)
+        except:
+            logging.error('error rewriting links on the following HTML content: {0}'.format(_html))
+
+        return _html
 
     def __init__(self, system, location, definition, descriptor,
                  instance_state=None, shared_state=None, **kwargs):

common/lib/xmodule/xmodule/x_module.py

@@ -328,7 +328,8 @@ class XModule(HTMLSnippet):
             name = link[len(XASSET_SRCREF_PREFIX):]
             loc = Location(self.location)
             # resolve the reference to our internal 'filepath' which
-            link = StaticContent.compute_location_filename(loc.org, loc.course, name)
+            content_loc = StaticContent.compute_location(loc.org, loc.course, name)
+            link = StaticContent.get_url_path_from_location(content_loc)
 
         return link