put back the inheritable_metadata list into the XModuleDescriptor class. Also extend the metadata_inheritance test case

cms/djangoapps/contentstore/tests/test_contentstore.py

@@ -431,6 +431,11 @@ class ContentStoreTest(ModuleStoreTestCase):
 
         verticals = ms.get_items(['i4x', 'edX', 'full', 'vertical', None, None])
 
+        # let's assert on the metadata_inheritance on an existing vertical
+        for vertical in verticals:
+            self.assertIn('xqa_key', vertical.metadata)
+            self.assertEqual(course.metadata['xqa_key'], vertical.metadata['xqa_key'])
+
         self.assertGreater(len(verticals), 0)
 
         new_component_location = Location('i4x', 'edX', 'full', 'html', 'new_component')
@@ -450,6 +455,18 @@ class ContentStoreTest(ModuleStoreTestCase):
 
         self.assertEqual(course.metadata['graceperiod'], new_module.metadata['graceperiod'])
 
+        #
+        # now let's define an override at the leaf node level
+        #
+        new_module.metadata['graceperiod'] = '1 day'
+        ms.update_metadata(new_module.location, new_module.metadata)
+
+        # flush the cache and refetch
+        ms.get_cached_metadata_inheritance_tree(new_component_location, -1)
+        new_module = ms.get_item(new_component_location)
+
+        self.assertIn('graceperiod', new_module.metadata)
+        self.assertEqual('1 day', new_module.metadata['graceperiod'])
 
 
 class TemplateTestCase(ModuleStoreTestCase):

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

@@ -11,7 +11,7 @@ from datetime import datetime, timedelta
 
 from importlib import import_module
 from xmodule.errortracker import null_error_tracker, exc_info_to_str
-from xmodule.x_module import XModuleDescriptor, inheritable_metadata
+from xmodule.x_module import XModuleDescriptor
 from xmodule.mako_module import MakoDescriptorSystem
 from xmodule.error_module import ErrorDescriptor
 
@@ -185,7 +185,7 @@ class MongoModuleStore(ModuleStoreBase):
         def _compute_inherited_metadata(url):
             my_metadata = results_by_url[url]['metadata']
             for key in my_metadata.keys():
-                if key not in inheritable_metadata:
+                if key not in XModuleDescriptor.inheritable_metadata:
                     del my_metadata[key]
             results_by_url[url]['metadata'] = my_metadata
 

common/lib/xmodule/xmodule/x_module.py

@@ -411,20 +411,6 @@ class ResourceTemplates(object):
 
         return templates
 
-# A list of metadata that this module can inherit from its parent module
-inheritable_metadata = (
-    'graded', 'start', 'due', 'graceperiod', 'showanswer', 'rerandomize',
-    # TODO (ichuang): used for Fall 2012 xqa server access
-    'xqa_key',
-    # TODO: This is used by the XMLModuleStore to provide for locations for
-    # static files, and will need to be removed when that code is removed
-    'data_dir',
-    # How many days early to show a course element to beta testers (float)
-    # intended to be set per-course, but can be overridden in for specific
-    # elements.  Can be a float.
-    'days_early_for_beta'
-)
-
 class XModuleDescriptor(Plugin, HTMLSnippet, ResourceTemplates):
     """
     An XModuleDescriptor is a specification for an element of a course. This
@@ -446,6 +432,20 @@ class XModuleDescriptor(Plugin, HTMLSnippet, ResourceTemplates):
     # It should respond to max_score() and grade(). It can be graded or ungraded
     # (like a practice problem).
 
+    # A list of metadata that this module can inherit from its parent module
+    inheritable_metadata = (
+        'graded', 'start', 'due', 'graceperiod', 'showanswer', 'rerandomize',
+        # TODO (ichuang): used for Fall 2012 xqa server access
+        'xqa_key',
+        # TODO: This is used by the XMLModuleStore to provide for locations for
+        # static files, and will need to be removed when that code is removed
+        'data_dir',
+        # How many days early to show a course element to beta testers (float)
+        # intended to be set per-course, but can be overridden in for specific
+        # elements.  Can be a float.
+        'days_early_for_beta'
+    )
+
     # cdodge: this is a list of metadata names which are 'system' metadata
     # and should not be edited by an end-user
     system_metadata_fields = ['data_dir', 'published_date', 'published_by', 'is_draft']
@@ -589,7 +589,7 @@ class XModuleDescriptor(Plugin, HTMLSnippet, ResourceTemplates):
         """
         # Set all inheritable metadata from kwargs that are
         # in inheritable_metadata and aren't already set in metadata
-        for attr in inheritable_metadata:
+        for attr in self.inheritable_metadata:
             if attr not in self.metadata and attr in metadata:
                 self._inherited_metadata.add(attr)
                 self.metadata[attr] = metadata[attr]