Add a compatibility function for get_course_lti_endpoints

This allows this xblock being hooked into get_course_lti_endpoints for
discovering LTI result/outcome endpoints.

Author: xcompass

lti_consumer/lti_consumer.py

@@ -562,6 +562,20 @@ def outcome_service_url(self):
         """
         return self.runtime.handler_url(self, "outcome_service_handler", thirdparty=True).rstrip('/?')
 
+    @property
+    def result_service_url(self):
+        """
+        Return URL for results.
+
+        To test LTI on sandbox we must use http scheme.
+
+        While testing locally and on Jenkins, mock_lti_server use http.referer
+        to obtain scheme, so it is ok to have http(s) anyway.
+
+        The scheme logic is handled in lms/lib/xblock/runtime.py
+        """
+        return self.runtime.handler_url(self, "result_service_handler", thirdparty=True).rstrip('/?')
+
     @property
     def prefixed_custom_parameters(self):
         """
@@ -860,3 +874,17 @@ def _get_modal_position_offset(self, viewport_percentage):
             float: The css position offset to apply to the modal window
         """
         return (100 - viewport_percentage) / 2
+
+    def get_outcome_service_url(self, service_name="grade_handler"):
+        """
+        This function is called by get_course_lti_endpoints when using LTI result service to
+        discover the LTI result endpoints.
+        """
+
+        # using string as mapped value instead of attributes to avoid unnecessary calls as both urls
+        # are @property.
+        mapping = {
+            'grade_handler': 'outcome_service_url',
+            'lti_2_0_result_rest_handler': 'result_service_url'
+        }
+        return getattr(self, mapping[service_name])

lti_consumer/tests/unit/test_lti_consumer.py

@@ -185,6 +185,17 @@ def test_outcome_service_url(self):
         self.xblock.runtime.handler_url.assert_called_with(self.xblock, 'outcome_service_handler', thirdparty=True)
         self.assertEqual(url, handler_url)
 
+    def test_result_service_url(self):
+        """
+        Test `result_service_url` calls `runtime.handler_url` with thirdparty kwarg
+        """
+        handler_url = 'http://localhost:8005/result_service_handler'
+        self.xblock.runtime.handler_url = Mock(return_value="{}/?".format(handler_url))
+        url = self.xblock.result_service_url
+
+        self.xblock.runtime.handler_url.assert_called_with(self.xblock, 'result_service_handler', thirdparty=True)
+        self.assertEqual(url, handler_url)
+
     def test_prefixed_custom_parameters(self):
         """
         Test `prefixed_custom_parameters` appropriately prefixes the configured custom params
@@ -528,6 +539,39 @@ def test_delete_result_called(self, mock_parse_suffix, mock_delete_result):
         assert mock_delete_result.called
         self.assertEqual(response.status_code, 200)
 
+    def test_get_outcome_service_url_with_default_parameter(self):
+        """
+        Test `get_outcome_service_url` with default parameter
+        """
+        handler_url = 'http://localhost:8005/outcome_service_handler'
+        self.xblock.runtime.handler_url = Mock(return_value="{}/?".format(handler_url))
+        url = self.xblock.get_outcome_service_url()
+
+        self.xblock.runtime.handler_url.assert_called_with(self.xblock, 'outcome_service_handler', thirdparty=True)
+        self.assertEqual(url, handler_url)
+
+    def test_get_outcome_service_url_with_service_name_grade_handler(self):
+        """
+        Test `get_outcome_service_url` calls service name grade_handler
+        """
+        handler_url = 'http://localhost:8005/outcome_service_handler'
+        self.xblock.runtime.handler_url = Mock(return_value="{}/?".format(handler_url))
+        url = self.xblock.get_outcome_service_url('grade_handler')
+
+        self.xblock.runtime.handler_url.assert_called_with(self.xblock, 'outcome_service_handler', thirdparty=True)
+        self.assertEqual(url, handler_url)
+
+    def test_get_outcome_service_url_with_service_name_lti_2_0_result_rest_handler(self):
+        """
+        Test `get_outcome_service_url` calls with service name lti_2_0_result_rest_handler
+        """
+        handler_url = 'http://localhost:8005/result_service_handler'
+        self.xblock.runtime.handler_url = Mock(return_value="{}/?".format(handler_url))
+        url = self.xblock.get_outcome_service_url('lti_2_0_result_rest_handler')
+
+        self.xblock.runtime.handler_url.assert_called_with(self.xblock, 'result_service_handler', thirdparty=True)
+        self.assertEqual(url, handler_url)
+
 
 class TestMaxScore(TestLtiConsumerXBlock):
     """