Merge pull request #150 from open-craft/pooja/fix-parameter-processor-logic

[SE-4235] Add missing parameter processors code

Author: giovannicimolin

lti_consumer/lti_1p1/consumer.py

@@ -146,6 +146,9 @@ def __init__(self, lti_launch_url, oauth_key, oauth_secret):
         self.lti_launch_presentation_locale = None
         self.lti_custom_parameters = None
 
+        # Extra claims - used for custom parameter processors
+        self.extra_claims = {}
+
     def set_user_data(
             self,
             user_id,
@@ -241,6 +244,14 @@ def set_custom_parameters(self, custom_parameters):
 
         self.lti_custom_parameters = custom_parameters
 
+    def set_extra_claims(self, claim):
+        """
+        Updates launch extra claims using python's dict .update method
+        """
+        if not isinstance(claim, dict):
+            raise ValueError('Invalid extra claim: {!r} is not a dict.'.format(claim))
+        self.extra_claims.update(claim)
+
     def generate_launch_request(self, resource_link_id):
         """
         Signs LTI launch request and returns signature and OAuth parameters.
@@ -288,6 +299,10 @@ def generate_launch_request(self, resource_link_id):
         if self.lti_custom_parameters:
             lti_parameters.update(self.lti_custom_parameters)
 
+        # Extra claims - from custom parameter processors
+        if self.extra_claims:
+            lti_parameters.update(self.extra_claims)
+
         headers = {
             # This is needed for body encoding:
             'Content-Type': 'application/x-www-form-urlencoded',

lti_consumer/lti_xblock.py

@@ -1009,6 +1009,16 @@ def lti_launch_handler(self, request, suffix=''):  # pylint: disable=unused-argu
 
         lti_consumer.set_custom_parameters(self.prefixed_custom_parameters)
 
+        for processor in self.get_parameter_processors():
+            try:
+                default_params = getattr(processor, 'lti_xblock_default_params', {})
+                lti_consumer.set_extra_claims(default_params)
+                lti_consumer.set_extra_claims(processor(self) or {})
+            except Exception:  # pylint: disable=broad-except
+                # Log the error without causing a 500-error.
+                # Useful for catching casual runtime errors in the processors.
+                log.exception('Error in XBlock LTI parameter processor "%s"', processor)
+
         lti_parameters = lti_consumer.generate_launch_request(self.resource_link_id)
         loader = ResourceLoader(__name__)
         context = self._get_context_for_template()

setup.py

@@ -49,7 +49,7 @@ def is_requirement(line):
 
 setup(
     name='lti-consumer-xblock',
-    version='3.0.2',
+    version='3.0.3',
     author='Open edX project',
     author_email='oscm@edx.org',
     description='This XBlock implements the consumer side of the LTI specification.',