added roles and student id

common/lib/xmodule/xmodule/lti_module.py

@@ -41,6 +41,8 @@ class LTIModule(LTIFields, XModule):
 
     def get_html(self):
         """ Renders parameters to template. """
+
+        # these params do not participate in oauth signing
         params = {
             'lti_url': self.lti_url,
             'element_id': self.location.html_id(),
@@ -55,15 +57,21 @@ class LTIModule(LTIFields, XModule):
             client_key=unicode(self.client_key),
             client_secret=unicode(self.client_secret)
         )
+
+        # @ned - why  self.runtime.anonymous_student_id is None in dev env?
+        user_id = self.runtime.anonymous_student_id
+        user_id = user_id if user_id else 'default_user_id'
+
         # must have parameters for correct signing from LTI:
         body = {
-            'user_id': 'default_user_id',
+            'user_id': user_id,
             'oauth_callback': 'about:blank',
             'lis_outcome_service_url': '',
             'lis_result_sourcedid': '',
             'launch_presentation_return_url': '',
             'lti_message_type': 'basic-lti-launch-request',
             'lti_version': 'LTI-1p0',
+            'role': 'student'
         }
         # This is needed for body encoding:
         headers = {'Content-Type': 'application/x-www-form-urlencoded'}
@@ -80,12 +88,15 @@ class LTIModule(LTIFields, XModule):
         params[u'oauth_nonce'] = params[u'OAuth oauth_nonce']
         del params[u'OAuth oauth_nonce']
 
+        params['user_id'] = body['user_id']
+
         # 0.14.2 (current) version of requests oauth library encodes signature,
         # with 'Content-Type': 'application/x-www-form-urlencoded'
         # so '='' becomes '%3D'.
         # We send form via browser, so browser will encode it again,
         # So we need to decode signature back:
         params[u'oauth_signature'] = urllib.unquote(params[u'oauth_signature']).decode('utf8')
+
         return params