Add get_courses() to mongo modulestore

* Note: This doesn't run yet
* add config file for lms on mongo
* Some comment additions and cleanups

common/lib/xmodule/xmodule/modulestore/__init__.py

@@ -221,3 +221,11 @@ class ModuleStore(object):
         metadata: A nested dictionary of module metadata
         """
         raise NotImplementedError
+
+    def get_courses(self):
+        '''
+        Returns a list containing the top level XModuleDescriptors of the courses
+        in this modulestore.
+        '''
+        raise NotImplementedError
+

common/lib/xmodule/xmodule/modulestore/mongo.py

 import pymongo
+
 from bson.objectid import ObjectId
+from fs.osfs import OSFS
 from importlib import import_module
 from xmodule.x_module import XModuleDescriptor
 from xmodule.mako_module import MakoDescriptorSystem
@@ -77,6 +79,7 @@ class MongoModuleStore(ModuleStore):
         # that is used when querying by a location
         self.collection.ensure_index(zip(('_id.' + field for field in Location._fields), repeat(1)))
 
+        # TODO (vshnayder): default arg default_class=None will make this error
         module_path, _, class_name = default_class.rpartition('.')
         class_ = getattr(import_module(module_path), class_name)
         self.default_class = class_
@@ -142,6 +145,14 @@ class MongoModuleStore(ModuleStore):
 
         return [self._load_item(item, data_cache) for item in items]
 
+    def get_courses(self):
+        '''
+        Returns a list of course descriptors.
+        '''
+        # TODO (vshnayder): Why do I have to specify i4x here?
+        course_filter = Location("i4x", category="course")
+        return self.get_items(course_filter)
+
     def get_item(self, location, depth=0):
         """
         Returns an XModuleDescriptor instance for the item at location.

common/lib/xmodule/xmodule/modulestore/xml.py

@@ -42,8 +42,8 @@ class XMLModuleStore(ModuleStore):
 
         self.eager = eager
         self.data_dir = path(data_dir)
-        self.modules = {}
-        self.courses = {}
+        self.modules = {}  # location -> XModuleDescriptor
+        self.courses = {}  # course_dir -> XModuleDescriptor for the course
 
         if default_class is None:
             self.default_class = None
@@ -77,20 +77,24 @@ class XMLModuleStore(ModuleStore):
 
         with open(self.data_dir / course_dir / "course.xml") as course_file:
 
-            # TODO (cpennington): Remove this once all fall 2012 courses have been imported into the cms from xml
+            # TODO (cpennington): Remove this once all fall 2012 courses have been imported
+            # into the cms from xml
             course_file = StringIO(clean_out_mako_templating(course_file.read()))
 
             course_data = etree.parse(course_file).getroot()
             org = course_data.get('org')
 
             if org is None:
-                log.error("No 'org' attribute set for course in {dir}. Using default 'edx'".format(dir=course_dir))
+                log.error(
+                    "No 'org' attribute set for course in {dir}. Using default 'edx'".format(
+                        dir=course_dir))
                 org = 'edx'
 
             course = course_data.get('course')
 
             if course is None:
-                log.error("No 'course' attribute set for course in {dir}. Using default '{default}'".format(
+                log.error(
+                    "No 'course' attribute set for course in {dir}. Using default '{default}'".format(
                     dir=course_dir,
                     default=course_dir
                 ))
@@ -106,7 +110,8 @@ class XMLModuleStore(ModuleStore):
 
                     def process_xml(xml):
                         try:
-                            # TODO (cpennington): Remove this once all fall 2012 courses have been imported into the cms from xml
+                            # TODO (cpennington): Remove this once all fall 2012 courses
+                            # have been imported into the cms from xml
                             xml = clean_out_mako_templating(xml)
                             xml_data = etree.fromstring(xml)
                         except:
@@ -117,17 +122,21 @@ class XMLModuleStore(ModuleStore):
                                 slug = Location.clean(xml_data.get('name'))
                             else:
                                 self.unnamed_modules += 1
-                                slug = '{tag}_{count}'.format(tag=xml_data.tag, count=self.unnamed_modules)
+                                slug = '{tag}_{count}'.format(tag=xml_data.tag,
+                                                              count=self.unnamed_modules)
 
                             if slug in self.used_slugs:
                                 self.unnamed_modules += 1
-                                slug = '{slug}_{count}'.format(slug=slug, count=self.unnamed_modules)
+                                slug = '{slug}_{count}'.format(slug=slug,
+                                                               count=self.unnamed_modules)
 
                             self.used_slugs.add(slug)
                             # log.debug('-> slug=%s' % slug)
                             xml_data.set('slug', slug)
 
-                        module = XModuleDescriptor.load_from_xml(etree.tostring(xml_data), self, org, course, xmlstore.default_class)
+                        module = XModuleDescriptor.load_from_xml(
+                            etree.tostring(xml_data), self, org,
+                            course, xmlstore.default_class)
                         log.debug('==> importing module location %s' % repr(module.location))
                         module.metadata['data_dir'] = course_dir
 
@@ -145,6 +154,7 @@ class XMLModuleStore(ModuleStore):
                     )
                     MakoDescriptorSystem.__init__(self, **system_kwargs)
                     XMLParsingSystem.__init__(self, **system_kwargs)
+                    
 
             course_descriptor = ImportSystem(self).process_xml(etree.tostring(course_data))
             log.debug('========> Done with course import')

common/lib/xmodule/xmodule/x_module.py

@@ -241,7 +241,7 @@ class XModuleDescriptor(Plugin):
         'data_dir'
     )
 
-    # A list of descriptor attributes that must be equal for the discriptors to be
+    # A list of descriptor attributes that must be equal for the descriptors to be
     # equal
     equality_attributes = ('definition', 'metadata', 'location', 'shared_state_key', '_inherited_metadata')
 

lms/envs/dev_mongo.py

+"""
+This config file runs the dev environment, but with mongo as the datastore
+"""
+from .dev import *
+
+MODULESTORE = {
+    'default': {
+        'ENGINE': 'xmodule.modulestore.mongo.MongoModuleStore',
+        'OPTIONS': {
+            'default_class': 'xmodule.raw_module.RawDescriptor',
+            'host': 'localhost',
+            'db': 'xmodule',
+            'collection': 'modulestore',
+        }
+    }
+}