Add support for the LTI Consumer XBlock (#142)

Author: OmarIthawi

.gitignore

@@ -15,6 +15,9 @@ geckodriver.log
 workbench/static/djpyfs/
 workbench.test.*
 
+### Developer Settings
+private.py
+
 # Documentation
 doc/_build
 .pip_cache

workbench/runtime.py

@@ -9,11 +9,14 @@
 import itertools
 import logging
 from collections import defaultdict
+from datetime import datetime, timedelta
 
+from mock import Mock
 from six import iteritems
 
 import django.utils.translation
 from django.conf import settings
+from django.contrib.auth.models import User
 from django.core.urlresolvers import reverse
 from django.template import loader as django_template_loader
 from django.templatetags.static import static
@@ -239,8 +242,9 @@ class WorkbenchRuntime(Runtime):
 
     A pre-configured instance of this class will be available to XBlocks as
     `self.runtime`.
-
     """
+    anonymous_student_id = 'dummydummy000-fake-fake-dummydummy00'  # Needed for the LTI XBlock
+    hostname = '127.0.0.1:8000'  # Arbitrary value, needed for the LTI XBlock
 
     def __init__(self, user_id=None):
         #  TODO: Add params for user, runtime, etc. to service initialization
@@ -264,8 +268,50 @@ def __init__(self, user_id=None):
         self.id_generator = ID_MANAGER
         self.user_id = user_id
 
+    def get_user_role(self):
+        """Provide a dummy user role."""
+        return 'Student'
+
+    @property
+    def descriptor_runtime(self):
+        """Provide a dummy course."""
+        course = Mock(
+            lti_passports=['test:test:secret'],
+            display_name_with_default='Test Course',
+            display_org_with_default='edX',
+        )
+
+        return Mock(modulestore=Mock(
+            get_course=Mock(return_value=course)
+        ))
+
+    def get_real_user(self, _):
+        """
+        Return a dummy user with a Mock profile.
+
+        Expected by the LTI Consumer XBlock.
+        """
+        u = User()
+        u.profile = Mock()
+        u.profile.name = 'John Doe'
+        return u
+
+    def _patch_xblock(self, block):
+        """Add required attributes by some legacy XBlocks such as the LTI Consumer XBlock."""
+        block.location = Mock(html_id=Mock(return_value='course-v1:edX+Demo+2020'))
+        block.course_id = block.location.html_id()
+        block.due = datetime.utcnow()
+        block.graceperiod = timedelta(seconds=0)
+        block.category = 'chapter'
+
+    def handle(self, block, handler_name, request, suffix=''):
+        """Patch the XBlock with required fields."""
+        self._patch_xblock(block)
+        return super(WorkbenchRuntime, self).handle(block, handler_name, request, suffix)
+
     def render(self, block, view_name, context=None):
         """Renders using parent class render() method"""
+        self._patch_xblock(block)
         try:
             return super(WorkbenchRuntime, self).render(block, view_name, context)
         except NoSuchViewError:

workbench/services.py

@@ -0,0 +1,30 @@
+"""
+Module contains various XBlock services for the workbench.
+"""
+from __future__ import unicode_literals
+
+from django.conf import settings
+
+
+class SettingsService(object):
+    """
+    Allows server-wide configuration of XBlocks on a per-type basis.
+
+    The service is copied as-is from the Open edX platform:
+
+      - `edx-platform/common/lib/xmodule/xmodule/services.py`
+    """
+    xblock_settings_bucket_selector = 'block_settings_key'
+
+    def get_settings_bucket(self, block, default=None):
+        """ Gets xblock settings dictionary from settings. """
+        if not block:
+            raise ValueError("Expected XBlock instance, got {block} of type {type}".format(
+                block=block,
+                type=type(block)
+            ))
+
+        actual_default = default if default is not None else {}
+        xblock_settings_bucket = getattr(block, self.xblock_settings_bucket_selector, block.unmixed_class.__name__)
+        xblock_settings = settings.XBLOCK_SETTINGS if hasattr(settings, "XBLOCK_SETTINGS") else {}
+        return xblock_settings.get(xblock_settings_bucket, actual_default)

workbench/settings.py

@@ -205,6 +205,12 @@
     ),
 
     'services': {
-        'fs': 'xblock.reference.plugins.FSService'
+        'fs': 'xblock.reference.plugins.FSService',
+        'settings': 'workbench.services.SettingsService',
     }
 }
+
+try:
+    from .private import *  # pylint: disable=wildcard-import,import-error,useless-suppression
+except ImportError:
+    pass

workbench/test/test_runtime.py

@@ -79,6 +79,22 @@ def test_asides(self):
         self.assertEqual(self.id_mgr.get_usage_id_from_aside(aside_usage), usage_id)
 
 
+class WorkbenchRuntimeTests(TestCase):
+    """
+    Tests for the WorkbenchRuntime.
+    """
+
+    def test_lti_consumer_xblock_requirements(self):
+        """
+        The LTI Consumer XBlock expects a lot of values from the LMS Runtime,
+        this test ensures that those requirements fulfilled.
+        """
+        runtime = WorkbenchRuntime('test_user')
+        assert runtime.get_real_user(object()), 'The LTI Consumer XBlock needs this method.'
+        assert runtime.hostname, 'The LTI Consumer XBlock needs this property.'
+        assert runtime.anonymous_student_id, 'The LTI Consumer XBlock needs this property.'
+
+
 class TestKVStore(TestCase):
     """
     Test the Workbench KVP Store