Make get_errored_courses part of the modulestore API (with default implementation).

Also clarifies the contraction of location.course_id by throwing an exception for lcoations that are not of category course.

Add test for course_id method.

cms/djangoapps/auth/tests/test_authz.py

@@ -181,7 +181,7 @@ class CourseGroupTest(TestCase):
         create_all_course_groups(self.creator, self.location)
         add_user_to_course_group(self.creator, self.staff, self.location, STAFF_ROLE_NAME)
 
-        location2 = 'i4x', 'mitX', '103', 'course2', 'test2'
+        location2 = 'i4x', 'mitX', '103', 'course', 'test2'
         staff2 = User.objects.create_user('teststaff2', 'teststaff2+courses@edx.org', 'foo')
         create_all_course_groups(self.creator, location2)
         add_user_to_course_group(self.creator, staff2, location2, STAFF_ROLE_NAME)
@@ -193,7 +193,7 @@ class CourseGroupTest(TestCase):
         create_all_course_groups(self.creator, self.location)
         add_user_to_course_group(self.creator, self.staff, self.location, STAFF_ROLE_NAME)
 
-        location2 = 'i4x', 'mitX', '103', 'course2', 'test2'
+        location2 = 'i4x', 'mitX', '103', 'course', 'test2'
         creator2 = User.objects.create_user('testcreator2', 'testcreator2+courses@edx.org', 'foo')
         staff2 = User.objects.create_user('teststaff2', 'teststaff2+courses@edx.org', 'foo')
         create_all_course_groups(creator2, location2)

common/djangoapps/student/views.py

@@ -274,7 +274,7 @@ def dashboard(request):
     # Global staff can see what courses errored on their dashboard
     staff_access = False
     errored_courses = {}
-    if has_access(user, 'global', 'staff') and callable(getattr(modulestore(), 'get_errored_courses')):
+    if has_access(user, 'global', 'staff'):
         # Show any courses that errored on load
         staff_access = True
         errored_courses = modulestore().get_errored_courses()

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

@@ -235,8 +235,15 @@ class Location(_LocationBase):
 
     @property
     def course_id(self):
-        """Return the ID of the Course that this item belongs to by looking
-        at the location URL hierachy"""
+        """
+        Return the ID of the Course that this item belongs to by looking
+        at the location URL hierachy.
+
+        Throws an InvalidLocationError is this location does not represent a course.
+        """
+        if self.category != 'course':
+            raise InvalidLocationError('Cannot call course_id for {0} because it is not of category course'.format(self))
+
         return "/".join([self.org, self.course, self.name])
 
     def replace(self, **kwargs):
@@ -370,6 +377,13 @@ class ModuleStore(object):
         '''
         raise NotImplementedError
 
+    def get_errored_courses(self):
+        """
+        Return a dictionary of course_dir -> [(msg, exception_str)], for each
+        course_dir where course loading failed.
+        """
+        raise NotImplementedError
+
 
 class ModuleStoreBase(ModuleStore):
     '''
@@ -409,6 +423,15 @@ class ModuleStoreBase(ModuleStore):
         errorlog = self._get_errorlog(location)
         return errorlog.errors
 
+    def get_errored_courses(self):
+        """
+        Returns an empty dict.
+
+        It is up to subclasses to extend this method if the concept
+        of errored courses makes sense for their implementation.
+        """
+        return {}
+
     def get_course(self, course_id):
         """Default impl--linear search through course list"""
         for c in self.get_courses():

common/lib/xmodule/xmodule/modulestore/tests/test_location.py

@@ -159,3 +159,12 @@ def test_clean_for_html():
 def test_html_id():
     loc = Location("tag://org/course/cat/name:more_name@rev")
     assert_equals(loc.html_id(), "tag-org-course-cat-name_more_name-rev")
+
+
+def test_course_id():
+    loc = Location('i4x', 'mitX', '103', 'course', 'test2')
+    assert_equals('mitX/103/test2', loc.course_id)
+
+    loc = Location('i4x', 'mitX', '103', '_not_a_course', 'test2')
+    with assert_raises(InvalidLocationError):
+        loc.course_id