LTI v1.3 Tool: A+ should not create LTI grade items if the Platform has disabled it

[markkuriekkinen]

If the LTI Platform (Moodle) defines in its LTI activity settings that no grades should be received from the LTI Tool, then A+ as the Tool should not (try to) create any grade items to the Platform.

For example, when a course is selected via LTI Deep Link, A+ does not check if the grades are enabled in the LTI settings:

a-plus/lti_tool/views.py

Lines 254 to 264 in a932c51

	def post(self, request, *args, **kwargs):
	# Create gradebook items
	ags = self.message_launch.get_ags()
	lineitems = ags.get_lineitems()
	exercises = BaseExercise.objects.filter(course_module__course_instance=self.instance)
	for e in exercises:
	lineitem_exists = bool([li for li in lineitems if li['tag'] == str(e.id)])
	if e.max_points > 0 and not lineitem_exists:
	li = LineItem()
	li.set_tag(str(e.id)).set_score_maximum(e.max_points).set_label(pick_localized(str(e), 'en'))
	ags.find_or_create_lineitem(li)

https://github.com/dmitry-viskov/pylti1.3#assignments-and-grades-service
Methods like

# ability to create new line item
ags.can_create_lineitem()