Add context_id.

CHANGELOG.rst

@@ -5,6 +5,8 @@ These are notable changes in edx-platform.  This is a rolling list of changes,
 in roughly chronological order, most recent first.  Add your entries at or near
 the top.  Include a label indicating the component affected.
 
+Blades: Add LTI context_id parameter. BLD-584.
+
 Blades: Update LTI resource_link_id parameter. BLD-768.
 
 Blades: Transcript translations should be displayed in their source language (BLD-935).

common/lib/xmodule/xmodule/js/fixtures/lti.html

@@ -28,6 +28,7 @@
             <input name="oauth_signature" value="89ru3289r3ry283y3r82ryr38yr" />
             <input name="lti_message_type" value="basic-lti-launch-request" />
             <input name="oauth_callback" value="about:blank" />
+            <input name="context_id" value="testorg/testcoursename/2014" />
 
             <input type="submit" value="Press to Launch" />
         </form>

common/lib/xmodule/xmodule/lti_module.py

@@ -338,13 +338,9 @@ class LTIModule(LTIFields, XModule):
         This value may change for a particular resource_link_id / user_id  from one launch to the next.
         The TP should only retain the most recent value for this field for a particular resource_link_id / user_id.
         This field is generally optional, but is required for grading.
-
-        context_id is - is an opaque identifier that uniquely identifies the context that contains
-        the link being launched.
-        lti_id should be context_id by meaning.
         """
-        return "{id}:{resource_link}:{user_id}".format(
-            id=urllib.quote(self.lti_id),
+        return "{context}:{resource_link}:{user_id}".format(
+            context=urllib.quote(self.context_id),
             resource_link=urllib.quote(self.get_resource_link_id()),
             user_id=urllib.quote(self.get_user_id())
         )
@@ -358,6 +354,16 @@ class LTIModule(LTIFields, XModule):
         return course
 
     @property
+    def context_id(self):
+        """
+        Return context_id.
+
+        context_id is an opaque identifier that uniquely identifies the context (e.g., a course)
+        that contains the link being launched.
+        """
+        return self.course_id
+
+    @property
     def role(self):
         """
         Get system user role and convert it to LTI role.
@@ -397,6 +403,7 @@ class LTIModule(LTIFields, XModule):
             u'resource_link_id': self.get_resource_link_id(),
             u'lis_result_sourcedid': self.get_lis_result_sourcedid(),
 
+            u'context_id': self.context_id,
         }
 
         if self.has_score:

common/lib/xmodule/xmodule/tests/__init__.py

@@ -131,7 +131,7 @@ class LogicTest(unittest.TestCase):
             url_name = ''
             category = 'test'
 
-        self.system = get_test_system()
+        self.system = get_test_system(course_id='test/course/id')
         self.descriptor = EmptyClass()
 
         self.xmodule_class = self.descriptor_class.module_class

common/lib/xmodule/xmodule/tests/test_lti_unit.py

@@ -265,7 +265,7 @@ class LTIModuleTest(LogicTest):
         with patch('xmodule.lti_module.LTIModule.location', new_callable=PropertyMock) as mock_location:
             self.xmodule.location.html_id = lambda: 'i4x-2-3-lti-31de800015cf4afb973356dbe81496df'
             expected_sourcedId = u':'.join(urllib.quote(i) for i in (
-                self.lti_id,
+                self.system.course_id,
                 urllib.quote(self.unquoted_resource_link_id),
                 self.user_id
             ))
@@ -407,4 +407,8 @@ class LTIModuleTest(LogicTest):
         self.xmodule.graded = False
         self.assertEqual(self.xmodule.max_score(), 100.0)
 
-
+    def test_context_id(self):
+        """
+        Tests that LTI parameter context_id is equal to course_id.
+        """
+        self.assertEqual(self.system.course_id, self.xmodule.context_id)

lms/djangoapps/courseware/tests/test_lti_integration.py

@@ -27,13 +27,13 @@ class TestLTI(BaseTestXmodule):
         mocked_signature_after_sign = u'my_signature%3D'
         mocked_decoded_signature = u'my_signature='
 
-        lti_id = self.item_descriptor.lti_id
+        context_id = self.item_descriptor.course_id
         user_id = unicode(self.item_descriptor.xmodule_runtime.anonymous_student_id)
         hostname = self.item_descriptor.xmodule_runtime.hostname
         resource_link_id = unicode(urllib.quote('{}-{}'.format(hostname, self.item_descriptor.location.html_id())))
 
-        sourcedId = "{id}:{resource_link}:{user_id}".format(
-            id=urllib.quote(lti_id),
+        sourcedId = "{context}:{resource_link}:{user_id}".format(
+            context=urllib.quote(context_id),
             resource_link=urllib.quote(resource_link_id),
             user_id=urllib.quote(user_id)
         )
@@ -49,6 +49,7 @@ class TestLTI(BaseTestXmodule):
             u'lti_message_type': u'basic-lti-launch-request',
             u'lti_version': 'LTI-1p0',
             u'roles': u'Student',
+            u'context_id': context_id,
 
             u'resource_link_id': resource_link_id,
             u'lis_result_sourcedid': sourcedId,