refactor: centralize learning MFE URL-building logic (#26689)

In preparation for switching LMS/Studio over
from serving legacy courseware URLs in certain
places (for example, resume_course_url) to serving
learning micro-frontend URLs.

TNL-7796

openedx/features/course_experience/api/v1/views.py

@@ -21,7 +21,6 @@ from opaque_keys.edx.keys import CourseKey
 
 from lms.djangoapps.course_api.api import course_detail
 from lms.djangoapps.course_home_api.toggles import course_home_mfe_dates_tab_is_active
-from lms.djangoapps.course_home_api.utils import get_microfrontend_url
 from lms.djangoapps.courseware.access import has_access
 from lms.djangoapps.courseware.courses import get_course_with_access
 from lms.djangoapps.courseware.masquerade import is_masquerading, setup_masquerade
@@ -29,6 +28,7 @@ from lms.djangoapps.courseware.masquerade import is_masquerading, setup_masquera
 from openedx.core.djangoapps.schedules.utils import reset_self_paced_schedule
 from openedx.core.lib.api.authentication import BearerAuthenticationAllowInactiveUser
 from openedx.features.course_experience.api.v1.serializers import CourseDeadlinesMobileSerializer
+from openedx.features.course_experience.url_helpers import get_learning_mfe_home_url
 from openedx.features.course_experience.utils import dates_banner_should_display
 
 log = logging.getLogger(__name__)
@@ -91,7 +91,7 @@ def reset_course_deadlines(request):
             tracker.emit('edx.ui.lms.reset_deadlines.clicked', research_event_data)
 
         if course_home_mfe_dates_tab_is_active(course_key):
-            body_link = get_microfrontend_url(course_key=str(course_key), view_name='dates')
+            body_link = get_learning_mfe_home_url(course_key=str(course_key), view_name='dates')
         else:
             body_link = '{}{}'.format(settings.LMS_ROOT_URL, reverse('dates', args=[str(course_key)]))
 

openedx/features/course_experience/url_helpers.py

@@ -0,0 +1,121 @@
+"""
+Helper functions for logic related to learning (courseare & course home) URLs.
+
+Centralizdd in openedx/features/course_experience instead of lms/djangoapps/courseware
+because the Studio course outline may need these utilities.
+"""
+import six
+from django.conf import settings
+from django.urls import reverse
+from six.moves.urllib.parse import urlencode
+
+from xmodule.modulestore.django import modulestore
+from xmodule.modulestore.search import navigation_index, path_to_location
+
+
+def get_legacy_courseware_url(course_key, usage_key, request=None):
+    """
+    Return a str with the URL for the specified legacy (LMS-rendered) coursweare content.
+
+    Args:
+        course_id(str): Course Id string
+        usage_key(str): The location id of course component
+
+    Raises:
+        ItemNotFoundError if no data at the location or NoPathToItem if location not in any class
+
+    Returns:
+        Redirect url string
+    """
+
+    (
+        course_key, chapter, section, vertical_unused,
+        position, final_target_id
+    ) = path_to_location(modulestore(), usage_key, request)
+
+    # choose the appropriate view (and provide the necessary args) based on the
+    # args provided by the redirect.
+    # Rely on index to do all error handling and access control.
+    if chapter is None:
+        redirect_url = reverse('courseware', args=(six.text_type(course_key), ))
+    elif section is None:
+        redirect_url = reverse('courseware_chapter', args=(six.text_type(course_key), chapter))
+    elif position is None:
+        redirect_url = reverse(
+            'courseware_section',
+            args=(six.text_type(course_key), chapter, section)
+        )
+    else:
+        # Here we use the navigation_index from the position returned from
+        # path_to_location - we can only navigate to the topmost vertical at the
+        # moment
+        redirect_url = reverse(
+            'courseware_position',
+            args=(six.text_type(course_key), chapter, section, navigation_index(position))
+        )
+    redirect_url += "?{}".format(urlencode({'activate_block_id': six.text_type(final_target_id)}))
+    return redirect_url
+
+
+def get_learning_mfe_courseware_url(course_key, sequence_key=None, unit_key=None):
+    """
+    Return a str with the URL for the specified coursweare content in the Learning MFE.
+
+    The micro-frontend determines the user's position in the vertical via
+    a separate API call, so all we need here is the course_key, section, and
+    vertical IDs to format it's URL. For simplicity and performance reasons,
+    this method does not inspect the modulestore to try to figure out what
+    Unit/Vertical a sequence is in. If you try to pass in a unit_key without
+    a sequence_key, the value will just be ignored and you'll get a URL pointing
+    to just the course_key.
+
+    It is also capable of determining our section and vertical if they're not
+    present.  Fully specifying it all is preferable, though, as the
+    micro-frontend can save itself some work, resulting in a better user
+    experience.
+
+    We're building a URL like this:
+
+    http://localhost:2000/course/course-v1:edX+DemoX+Demo_Course/block-v1:edX+DemoX+Demo_Course+type@sequential+block@19a30717eff543078a5d94ae9d6c18a5/block-v1:edX+DemoX+Demo_Course+type@vertical+block@4a1bba2a403f40bca5ec245e945b0d76
+
+    `course_key`, `sequence_key`, and `unit_key` can be either OpaqueKeys or
+    strings. They're only ever used to concatenate a URL string.
+    """
+    mfe_link = '{}/course/{}'.format(settings.LEARNING_MICROFRONTEND_URL, course_key)
+
+    if sequence_key:
+        mfe_link += '/{}'.format(sequence_key)
+
+        if unit_key:
+            mfe_link += '/{}'.format(unit_key)
+
+    return mfe_link
+
+
+def get_learning_mfe_home_url(course_key, view_name=None):
+    """
+    Given a course run key and view name, return the appropriate course home (MFE) URL.
+
+    We're building a URL like this:
+
+    http://localhost:2000/course/course-v1:edX+DemoX+Demo_Course/dates
+
+    `course_key` can be either an OpaqueKey or a string.
+    `view_name` is an optional string.
+    """
+    mfe_link = f'{settings.LEARNING_MICROFRONTEND_URL}/course/{course_key}'
+
+    if view_name:
+        mfe_link += f'/{view_name}'
+
+    return mfe_link
+
+
+def is_request_from_learning_mfe(request):
+    """
+    Returns whether the given request was made by the frontend-app-learning MFE.
+    """
+    return (
+        settings.LEARNING_MICROFRONTEND_URL and
+        request.META.get('HTTP_REFERER', '').startswith(settings.LEARNING_MICROFRONTEND_URL)
+    )

openedx/features/course_experience/views/course_dates.py

@@ -15,7 +15,7 @@ from web_fragments.fragment import Fragment
 from lms.djangoapps.courseware.courses import get_course_date_blocks, get_course_with_access
 from lms.djangoapps.courseware.tabs import DatesTab
 from lms.djangoapps.course_home_api.toggles import course_home_mfe_dates_tab_is_active
-from lms.djangoapps.course_home_api.utils import get_microfrontend_url
+from openedx.features.course_experience.url_helpers import get_learning_mfe_home_url
 from openedx.core.djangoapps.plugin_api.views import EdxFragmentView
 
 
@@ -35,7 +35,7 @@ class CourseDatesFragmentView(EdxFragmentView):
 
         dates_tab_enabled = DatesTab.is_enabled(course, request.user)
         if course_home_mfe_dates_tab_is_active(course_key):
-            dates_tab_link = get_microfrontend_url(course_key=course.id, view_name='dates')
+            dates_tab_link = get_learning_mfe_home_url(course_key=course.id, view_name='dates')
         else:
             dates_tab_link = reverse('dates', args=[course.id])
 

openedx/features/course_experience/views/course_home.py

@@ -15,7 +15,6 @@ from opaque_keys.edx.keys import CourseKey
 from web_fragments.fragment import Fragment
 
 from lms.djangoapps.course_home_api.toggles import course_home_mfe_outline_tab_is_active
-from lms.djangoapps.course_home_api.utils import get_microfrontend_url
 from lms.djangoapps.courseware.access import has_access
 from lms.djangoapps.courseware.courses import can_self_enroll_in_course, get_course_info_section, get_course_with_access
 from lms.djangoapps.course_goals.api import (
@@ -33,6 +32,7 @@ from openedx.core.djangoapps.plugin_api.views import EdxFragmentView
 from openedx.core.djangoapps.util.maintenance_banner import add_maintenance_banner
 from openedx.features.course_duration_limits.access import generate_course_expired_fragment
 from openedx.features.course_experience.course_tools import CourseToolsPluginManager
+from openedx.features.course_experience.url_helpers import get_learning_mfe_home_url
 from openedx.features.discounts.utils import get_first_purchase_offer_banner_fragment
 from openedx.features.discounts.utils import format_strikeout_price
 from common.djangoapps.student.models import CourseEnrollment
@@ -72,7 +72,7 @@ class CourseHomeView(CourseTabView):
     def render_to_fragment(self, request, course=None, tab=None, **kwargs):  # lint-amnesty, pylint: disable=arguments-differ, unused-argument
         course_id = six.text_type(course.id)
         if course_home_mfe_outline_tab_is_active(course.id) and not request.user.is_staff:
-            microfrontend_url = get_microfrontend_url(course_key=course_id, view_name="home")
+            microfrontend_url = get_learning_mfe_home_url(course_key=course_id, view_name="home")
             raise Redirect(microfrontend_url)
         home_fragment_view = CourseHomeFragmentView()
         return home_fragment_view.render_to_fragment(request, course_id=course_id, **kwargs)