LTI Tool v1.3: remove staff buttons in exercise and submission views

The staff views have not been implemented for the LTI Tool.
The views do not currently support opening in iframes and they
include navigation bars that have been removed in LTI Tool views.

Fixes #1115

Author: EerikSaksi

exercise/templates/exercise/exercise_base.html

@@ -93,23 +93,25 @@
 			{% if is_course_staff %}
 			<li>
 					<p class="navbar-text navbar-btn">
-							{% if submission %}
+							{% if submission and not disable_staff_nav %}
 							<a href="{{ submission|url:'submission-inspect' }}" role="button" class="aplus-button--secondary aplus-button--xs">
 									<span class="glyphicon glyphicon-zoom-in" aria-hidden="true"></span>
 									{% translate "INSPECT_SUBMISSION" %}
 							</a>
-							{% elif is_teacher %}
+							{% elif is_teacher and not disable_staff_nav %}
 							{% load editcourse %}
 							<a href="{{ exercise|editurl:'exercise' }}" role="button" class="aplus-button--secondary aplus-button--xs">
 									<span class="glyphicon glyphicon-edit" aria-hidden="true"></span>
 									{% translate "EDIT_EXERCISE" %}
 							</a>
 							{% endif %}
-							{% if is_teacher or exercise.allow_assistant_viewing %}
-							<a href="{{ exercise|url:'submission-list' }}" role="button" class="aplus-button--secondary aplus-button--xs">
-									<span class="glyphicon glyphicon-list" aria-hidden="true"></span>
-									{% translate "VIEW_ALL_SUBMISSIONS" %}
-							</a>
+							{% if not disable_staff_nav %}
+								{% if is_teacher or exercise.allow_assistant_viewing %}
+								<a href="{{ exercise|url:'submission-list' }}" role="button" class="aplus-button--secondary aplus-button--xs">
+										<span class="glyphicon glyphicon-list" aria-hidden="true"></span>
+										{% translate "VIEW_ALL_SUBMISSIONS" %}
+								</a>
+								{% endif %}
 							{% endif %}
 					</p>
 			</li>

lti_tool/views.py

@@ -128,6 +128,11 @@ def parse_lti_session_params(self):
             )
             self.message_launch_data = self.message_launch.get_launch_data()
 
+    def get_common_objects(self):
+        super().get_common_objects()
+        self.disable_staff_nav = True
+        self.note("disable_staff_nav")
+
 
 class LtiInstanceView(LtiSessionMixin, InstanceView):