Fix Start Course vs Resume Course using Course Blocks.

lms/djangoapps/course_blocks/transformers/library_content.py

@@ -12,6 +12,8 @@ from xmodule.modulestore.django import modulestore
 from eventtracking import tracker
 from track import contexts
 
+from ..utils import get_student_module_as_dict
+
 
 class ContentLibraryTransformer(FilteringTransformerMixin, BlockStructureTransformer):
     """
@@ -78,12 +80,7 @@ class ContentLibraryTransformer(FilteringTransformerMixin, BlockStructureTransfo
                 max_count = block_structure.get_xblock_field(block_key, 'max_count')
 
                 # Retrieve "selected" json from LMS MySQL database.
-                module = self._get_student_module(usage_info.user, usage_info.course_key, block_key)
-                if module:
-                    state_dict = json.loads(module.state)
-                else:
-                    state_dict = {}
-
+                state_dict = get_student_module_as_dict(usage_info.user, usage_info.course_key, block_key)
                 for selected_block in state_dict.get('selected', []):
                     # Add all selected entries for this user for this
                     # library module to the selected list.
@@ -135,28 +132,6 @@ class ContentLibraryTransformer(FilteringTransformerMixin, BlockStructureTransfo
 
         return [block_structure.create_removal_filter(check_child_removal)]
 
-    @classmethod
-    def _get_student_module(cls, user, course_key, block_key):
-        """
-        Get the student module for the given user for the given block.
-
-        Arguments:
-            user (User)
-            course_key (CourseLocator)
-            block_key (BlockUsageLocator)
-
-        Returns:
-            StudentModule if exists, or None.
-        """
-        try:
-            return StudentModule.objects.get(
-                student=user,
-                course_id=course_key,
-                module_state_key=block_key,
-            )
-        except StudentModule.DoesNotExist:
-            return None
-
     def _publish_events(self, block_structure, location, previous_count, max_count, block_keys, user_id):
         """
         Helper method to publish events for analytics purposes

lms/djangoapps/course_blocks/utils.py

@@ -0,0 +1,32 @@
+"""
+Common utilities for use along with the course blocks.
+"""
+import json
+from courseware.models import StudentModule
+
+
+def get_student_module_as_dict(user, course_key, block_key):
+    """
+    Get the student module as a dict for the given user for the given block.
+
+    Arguments:
+        user (User)
+        course_key (CourseLocator)
+        block_key (BlockUsageLocator)
+
+    Returns:
+        StudentModule as a (possibly empty) dict.
+    """
+    try:
+        student_module = StudentModule.objects.get(
+            student=user,
+            course_id=course_key,
+            module_state_key=block_key,
+        )
+    except StudentModule.DoesNotExist:
+        student_module = None
+
+    if student_module:
+        return json.loads(student_module.state)
+    else:
+        return {}

lms/djangoapps/courseware/courses.py

@@ -518,28 +518,3 @@ def get_current_child(xmodule, min_depth=None, requested_child=None):
                 child = _get_default_child_module(children)
 
     return child
-
-
-def get_last_accessed_courseware(course, request, user):
-    """
-    Returns a tuple containing the courseware module (URL, id) that the user last accessed,
-    or (None, None) if it cannot be found.
-    """
-    # TODO: convert this method to use the Course Blocks API
-    field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
-        course.id, request.user, course, depth=2
-    )
-    course_module = get_module_for_descriptor(
-        user, request, course, field_data_cache, course.id, course=course
-    )
-    chapter_module = get_current_child(course_module)
-    if chapter_module is not None:
-        section_module = get_current_child(chapter_module)
-        if section_module is not None:
-            url = reverse('courseware_section', kwargs={
-                'course_id': unicode(course.id),
-                'chapter': chapter_module.url_name,
-                'section': section_module.url_name
-            })
-            return (url, section_module.url_name)
-    return (None, None)

lms/djangoapps/courseware/views/views.py

@@ -66,7 +66,7 @@ from courseware.courses import (
     get_course_by_id,
     get_course_overview_with_access,
     get_course_with_access,
-    get_last_accessed_courseware,
+    get_current_child,
     get_permission_for_course_about,
     get_studio_url,
     sort_by_announcement,
@@ -97,7 +97,6 @@ from openedx.features.course_experience import (
     UNIFIED_COURSE_VIEW_FLAG,
 )
 from openedx.features.enterprise_support.api import data_sharing_consent_required
-from shoppingcart.models import CourseRegistrationCode
 from shoppingcart.utils import is_shopping_cart_enabled
 from student.models import UserTestGroup, CourseEnrollment
 from survey.utils import must_answer_survey
@@ -249,6 +248,28 @@ def course_info(request, course_id):
 
     Assumes the course_id is in a valid format.
     """
+    def get_last_accessed_courseware(course, request, user):
+        """
+        Returns the courseware module URL that the user last accessed, or None if it cannot be found.
+        """
+        field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
+            course.id, request.user, course, depth=2
+        )
+        course_module = get_module_for_descriptor(
+            user, request, course, field_data_cache, course.id, course=course
+        )
+        chapter_module = get_current_child(course_module)
+        if chapter_module is not None:
+            section_module = get_current_child(chapter_module)
+            if section_module is not None:
+                url = reverse('courseware_section', kwargs={
+                    'course_id': unicode(course.id),
+                    'chapter': chapter_module.url_name,
+                    'section': section_module.url_name
+                })
+                return url
+        return None
+
     # If the unified course experience is enabled, redirect to the "Course" tab
     if waffle.flag_is_active(request, UNIFIED_COURSE_EXPERIENCE_FLAG):
         return redirect(reverse(course_home_url_name(request), args=[course_id]))
@@ -343,7 +364,7 @@ def course_info(request, course_id):
         # Get the URL of the user's last position in order to display the 'where you were last' message
         context['last_accessed_courseware_url'] = None
         if SelfPacedConfiguration.current().enable_course_home_improvements:
-            context['last_accessed_courseware_url'], _ = get_last_accessed_courseware(course, request, user)
+            context['last_accessed_courseware_url'] = get_last_accessed_courseware(course, request, user)
 
         now = datetime.now(UTC())
         effective_start = _adjust_start_date_for_beta_testers(user, course, course_key)