[BD-32] feat: add filter before course home rendering process starts

openedx/features/course_experience/tests/test_filters.py

@@ -0,0 +1,172 @@
+"""
+Test that various filters are fired for course_experience views.
+"""
+from django.test import override_settings
+from django.urls import reverse
+from edx_toggles.toggles.testutils import override_waffle_flag
+from openedx_filters import PipelineStep
+from openedx_filters.learning.filters import CourseHomeRenderStarted
+from rest_framework import status
+
+from lms.djangoapps.course_home_api.toggles import COURSE_HOME_USE_LEGACY_FRONTEND
+from openedx.core.djangolib.testing.utils import skip_unless_lms
+from openedx.features.course_experience.tests.views.test_course_home import TEST_WELCOME_MESSAGE, CourseHomePageTestCase
+
+
+class TestStopCourseHomeRenderStep(PipelineStep):
+    """
+    Utility class used when getting steps for pipeline.
+    """
+
+    def run_filter(self, context, template_name):  # pylint: disable=arguments-differ
+        """
+        Pipeline step that stops the course home render process.
+
+        When raising PreventCourseHomeRender, this filter overrides the course home
+        template name so the view renders a module-error instead.
+        """
+        raise CourseHomeRenderStarted.PreventCourseHomeRender(
+            "You can't access the courses home page.",
+            course_home_template="module-error.html",
+            template_context=context,
+        )
+
+
+class TestRedirectCourseHomePageStep(PipelineStep):
+    """
+    Utility class used when getting steps for pipeline.
+    """
+
+    def run_filter(self, context, template_name):  # pylint: disable=arguments-differ
+        """
+        Pipeline step that redirects to the course survey.
+
+        When raising RedirectCourseHomePage, this filter uses a redirect_to field handled by
+        the course home view that redirects to the URL indicated.
+        """
+        raise CourseHomeRenderStarted.RedirectCourseHomePage(
+            "You can't access this courses home page, redirecting to the correct location.",
+            redirect_to="https://course-home-elsewhere.com",
+        )
+
+
+class TestCourseHomeRenderStep(PipelineStep):
+    """
+    Utility class used when getting steps for pipeline.
+    """
+
+    def run_filter(self, context, template_name):  # pylint: disable=arguments-differ
+        """Pipeline step that removes any update messages."""
+        context["update_message_fragment"] = None
+        return {
+            "context": context, template_name: template_name,
+        }
+
+
+@skip_unless_lms
+class CourseHomeFiltersTest(CourseHomePageTestCase):
+    """
+    Tests for the Open edX Filters associated with the course home rendering process.
+
+    This class guarantees that the following filters are triggered during the course home rendering:
+
+    - CourseHomeRenderStarted
+    """
+
+    def setUp(self):  # pylint: disable=arguments-differ
+        super().setUp()
+        self.course_home_url = reverse(
+            'openedx.course_experience.course_home',
+            kwargs={
+                'course_id': self.course.id,
+            }
+        )
+
+    @override_settings(
+        OPEN_EDX_FILTERS_CONFIG={
+            "org.openedx.learning.course_home.render.started.v1": {
+                "pipeline": [
+                    "openedx.features.course_experience.tests.test_filters.TestCourseHomeRenderStep",
+                ],
+                "fail_silently": False,
+            },
+        },
+    )
+    @override_waffle_flag(COURSE_HOME_USE_LEGACY_FRONTEND, active=True)
+    def test_dashboard_render_filter_executed(self):
+        """
+        Test whether the course home filter is triggered before the course home view
+        renders.
+
+        Expected result:
+            - CourseHomeRenderStarted is triggered and executes TestCourseHomeRenderStep.
+            - The course home renders without the welcome message.
+        """
+        self.create_course_update(TEST_WELCOME_MESSAGE)
+
+        response = self.client.get(self.course_home_url)
+
+        self.assertNotContains(response, TEST_WELCOME_MESSAGE, status_code=200)
+
+    @override_settings(
+        OPEN_EDX_FILTERS_CONFIG={
+            "org.openedx.learning.course_home.render.started.v1": {
+                "pipeline": [
+                    "openedx.features.course_experience.tests.test_filters.TestStopCourseHomeRenderStep",
+                ],
+                "fail_silently": False,
+            },
+        },
+    )
+    @override_waffle_flag(COURSE_HOME_USE_LEGACY_FRONTEND, active=True)
+    def test_course_home_render_invalid(self):
+        """
+        Test rendering an error template after catching PreventCourseHomeRender exception.
+
+        Expected result:
+            - CourseHomeRenderStarted is triggered and executes TestStopCourseHomeRenderStep.
+            - The module-error template is rendered.
+        """
+        response = self.client.get(self.course_home_url)
+
+        self.assertContains(response, "There has been an error on the {platform_name} servers")
+
+    @override_settings(
+        OPEN_EDX_FILTERS_CONFIG={
+            "org.openedx.learning.course_home.render.started.v1": {
+                "pipeline": [
+                    "openedx.features.course_experience.tests.test_filters.TestRedirectCourseHomePageStep",
+                ],
+                "fail_silently": False,
+            },
+        },
+    )
+    @override_waffle_flag(COURSE_HOME_USE_LEGACY_FRONTEND, active=True)
+    def test_redirect_redirect(self):
+        """
+        Test redirecting to a new page after catching RedirectCourseHomePage exception.
+
+        Expected result:
+            - CourseHomeRenderStarted is triggered and executes TestCertificatePipelineStep.
+            - The view response is a redirection.
+        """
+        response = self.client.get(self.course_home_url)
+
+        self.assertEqual(status.HTTP_302_FOUND, response.status_code)
+
+    @override_settings(OPEN_EDX_FILTERS_CONFIG={})
+    @override_waffle_flag(COURSE_HOME_USE_LEGACY_FRONTEND, active=True)
+    def test_dashboard_render_without_filter_config(self):
+        """
+        Test whether the course home filter is triggered before the course home
+        render without affecting its execution flow.
+
+        Expected result:
+            - CourseHomeRenderStarted executes a noop (empty pipeline).
+            - The webview response is HTTP_200_OK.
+        """
+        self.create_course_update(TEST_WELCOME_MESSAGE)
+
+        response = self.client.get(self.course_home_url)
+
+        self.assertContains(response, TEST_WELCOME_MESSAGE, status_code=200)

openedx/features/course_experience/views/course_home.py

@@ -11,6 +11,7 @@
 from django.views.decorators.cache import cache_control
 from django.views.decorators.csrf import ensure_csrf_cookie
 from opaque_keys.edx.keys import CourseKey
+from openedx_filters.learning.filters import CourseHomeRenderStarted
 from web_fragments.fragment import Fragment
 
 from lms.djangoapps.course_home_api.toggles import course_home_legacy_is_active
@@ -240,5 +241,19 @@ def render_to_fragment(self, request, course_id=None, **kwargs):  # lint-amnesty
             'has_discount': has_discount,
             'show_search': show_search,
         }
-        html = render_to_string('course_experience/course-home-fragment.html', context)
+
+        course_home_template = 'course_experience/course-home-fragment.html'
+        try:
+            # .. filter_implemented_name: CourseHomeRenderStarted
+            # .. filter_type: org.openedx.learning.course_home.render.started.v1
+            context, course_home_template = CourseHomeRenderStarted.run_filter(
+                context=context, template_name=course_home_template,
+            )
+        except CourseHomeRenderStarted.PreventCourseHomeRender as exc:
+            html = render_to_string(exc.course_home_template, exc.template_context)
+        except CourseHomeRenderStarted.RedirectCourseHomePage as exc:
+            raise CourseAccessRedirect(exc.redirect_to or reverse("dashboard")) from exc
+        else:
+            html = render_to_string(course_home_template, context)
+
         return Fragment(html)

requirements/edx/base.txt

@@ -713,7 +713,7 @@ openedx-calc==3.0.1
     # via -r requirements/edx/base.in
 openedx-events==0.8.1
     # via -r requirements/edx/base.in
-openedx-filters==0.5.0
+git+https://github.com/eduNEXT/openedx-filters.git@MJG/template-exceptions#egg=openedx_filters==0.6.0_beta
     # via -r requirements/edx/base.in
 ora2==4.0.6
     # via -r requirements/edx/base.in

requirements/edx/development.txt

@@ -951,7 +951,7 @@ openedx-calc==3.0.1
     # via -r requirements/edx/testing.txt
 openedx-events==0.8.1
     # via -r requirements/edx/testing.txt
-openedx-filters==0.5.0
+git+https://github.com/eduNEXT/openedx-filters.git@MJG/template-exceptions#egg=openedx_filters==0.6.0_beta
     # via -r requirements/edx/testing.txt
 ora2==4.0.6
     # via -r requirements/edx/testing.txt

requirements/edx/testing.txt

@@ -899,7 +899,7 @@ openedx-calc==3.0.1
     # via -r requirements/edx/base.txt
 openedx-events==0.8.1
     # via -r requirements/edx/base.txt
-openedx-filters==0.5.0
+git+https://github.com/eduNEXT/openedx-filters.git@MJG/template-exceptions#egg=openedx_filters==0.6.0_beta
     # via -r requirements/edx/base.txt
 ora2==4.0.6
     # via -r requirements/edx/base.txt