From a9d67c3e8d4276ae59cc00a79dd9ecb6baff74c8 Mon Sep 17 00:00:00 2001
From: Bridger Maxwell <bridgeyman@gmail.com>
Date: Tue, 7 Aug 2012 15:20:47 -0400
Subject: [PATCH] Added has_score attribute to xmodule, for problem-like
 xmodules.

---
 common/lib/xmodule/xmodule/capa_module.py   | 1 +
 common/lib/xmodule/xmodule/course_module.py | 8 ++++----
 common/lib/xmodule/xmodule/x_module.py      | 3 +++
 lms/djangoapps/courseware/grades.py         | 4 ++--
 4 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/common/lib/xmodule/xmodule/capa_module.py b/common/lib/xmodule/xmodule/capa_module.py
index 7ca33841dc..5501d6301c 100644
--- a/common/lib/xmodule/xmodule/capa_module.py
+++ b/common/lib/xmodule/xmodule/capa_module.py
@@ -564,6 +564,7 @@ class CapaDescriptor(RawDescriptor):
     module_class = CapaModule
     
     stores_state = True
+    has_score = True
 
     # Capa modules have some additional metadata:
     # TODO (vshnayder): do problems have any other metadata?  Do they
diff --git a/common/lib/xmodule/xmodule/course_module.py b/common/lib/xmodule/xmodule/course_module.py
index ce1b93aa44..7ec9f54cd2 100644
--- a/common/lib/xmodule/xmodule/course_module.py
+++ b/common/lib/xmodule/xmodule/course_module.py
@@ -99,10 +99,10 @@ class CourseDescriptor(SequenceDescriptor):
             sections = []
             for s in c.get_children():
                 if s.metadata.get('graded', False):
-                    # TODO: Only include modules that have a score here
-                    xmoduledescriptors = [child for child in yield_descriptor_descendents(s)]
-
-                    section_description = { 'section_descriptor' : s, 'xmoduledescriptors' : xmoduledescriptors}
+                    xmoduledescriptors = list(yield_descriptor_descendents(s))
+                    
+                    # The xmoduledescriptors included here are only the ones that have scores.
+                    section_description = { 'section_descriptor' : s, 'xmoduledescriptors' : filter(lambda child: child.has_score, xmoduledescriptors) }
 
                     section_format = s.metadata.get('format', "")
                     graded_sections[ section_format ] = graded_sections.get( section_format, [] ) + [section_description]
diff --git a/common/lib/xmodule/xmodule/x_module.py b/common/lib/xmodule/xmodule/x_module.py
index 9ed1854c5b..7bc8a72731 100644
--- a/common/lib/xmodule/xmodule/x_module.py
+++ b/common/lib/xmodule/xmodule/x_module.py
@@ -308,6 +308,9 @@ class XModuleDescriptor(Plugin, HTMLSnippet):
     # Attributes for inpsection of the descriptor
     stores_state = False # Indicates wether the xmodule state should be 
     # stored in a database (independent of shared state)
+    has_score = False # This indicates whether the xmodule is a problem-type.
+    # 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 = (
diff --git a/lms/djangoapps/courseware/grades.py b/lms/djangoapps/courseware/grades.py
index 926040ab6f..737e4245e0 100644
--- a/lms/djangoapps/courseware/grades.py
+++ b/lms/djangoapps/courseware/grades.py
@@ -183,8 +183,8 @@ def get_score(user, problem, student_module_cache):
     problem: an XModule
     cache: A StudentModuleCache
     """
-    if not problem.descriptor.stores_state:
-        # These are not problems, and do not store state
+    if not problem.descriptor.stores_state or not problem.descriptor.has_score:
+        # These are not problems, and do not have a score
         return (None, None)
     
     correct = 0.0