Merge pull request #12975 from edx/tnl/hide_content

LMS Hide Subsection Content

common/lib/xmodule/xmodule/seq_module.py

@@ -4,6 +4,8 @@ xModule implementation of a learning sequence
 
 # pylint: disable=abstract-method
 import collections
+from datetime import datetime
+from django.utils.timezone import UTC
 import json
 import logging
 from pkg_resources import resource_string
@@ -38,13 +40,22 @@ class SequenceFields(object):
     # NOTE: Position is 1-indexed.  This is silly, but there are now student
     # positions saved on prod, so it's not easy to fix.
     position = Integer(help="Last tab viewed in this sequence", scope=Scope.user_state)
+
     due = Date(
         display_name=_("Due Date"),
         help=_("Enter the date by which problems are due."),
         scope=Scope.settings,
     )
 
-    # Entrance Exam flag -- see cms/contentstore/views/entrance_exam.py for usage
+    hide_after_due = Boolean(
+        display_name=_("Hide sequence content After Due Date"),
+        help=_(
+            "If set, the sequence content is hidden for non-staff users after the due date has passed."
+        ),
+        default=False,
+        scope=Scope.settings,
+    )
+
     is_entrance_exam = Boolean(
         display_name=_("Is Entrance Exam"),
         help=_(
@@ -97,16 +108,6 @@ class ProctoringFields(object):
         scope=Scope.settings,
     )
 
-    hide_after_due = Boolean(
-        display_name=_("Hide Exam Results After Due Date"),
-        help=_(
-            "This setting overrides the default behavior of showing exam results after the due date has passed."
-            " Currently only supported for timed exams."
-        ),
-        default=False,
-        scope=Scope.settings,
-    )
-
     is_practice_exam = Boolean(
         display_name=_("Is Practice Exam"),
         help=_(
@@ -177,73 +178,91 @@ class SequenceModule(SequenceFields, ProctoringFields, XModule):
 
         raise NotFoundError('Unexpected dispatch type')
 
+    @classmethod
+    def verify_current_content_visibility(cls, due, hide_after_due):
+        """
+        Returns whether the content visibility policy passes
+        for the given due date and hide_after_due values and
+        the current date-time.
+        """
+        return (
+            not due or
+            not hide_after_due or
+            datetime.now(UTC()) < due
+        )
+
     def student_view(self, context):
+        context = context or {}
+        self._capture_basic_metrics()
+        banner_text = None
+        special_html_view = self._hidden_content_student_view(context) or self._special_exam_student_view()
+        if special_html_view:
+            masquerading_as_specific_student = context.get('specific_masquerade', False)
+            banner_text, special_html = special_html_view
+            if special_html and not masquerading_as_specific_student:
+                return Fragment(special_html)
+        return self._student_view(context, banner_text)
+
+    def _special_exam_student_view(self):
+        """
+        Checks whether this sequential is a special exam.  If so, returns
+        a banner_text or the fragment to display depending on whether
+        staff is masquerading.
+        """
+        if self.is_time_limited:
+            special_exam_html = self._time_limited_student_view()
+            if special_exam_html:
+                banner_text = _("This exam is hidden from the learner.")
+                return banner_text, special_exam_html
+
+    def _hidden_content_student_view(self, context):
+        """
+        Checks whether the content of this sequential is hidden from the
+        runtime user. If so, returns a banner_text or the fragment to
+        display depending on whether staff is masquerading.
+        """
+        if not self._can_user_view_content():
+            subsection_format = (self.format or _("subsection")).lower()  # pylint: disable=no-member
+
+            # Translators: subsection_format refers to the assignment
+            # type of the subsection, such as Homework, Lab, Exam, etc.
+            banner_text = _(
+                "Because the due date has passed, "
+                "this {subsection_format} is hidden from the learner."
+            ).format(subsection_format=subsection_format)
+
+            hidden_content_html = self.system.render_template(
+                'hidden_content.html',
+                {
+                    'subsection_format': subsection_format,
+                    'progress_url': context.get('progress_url'),
+                }
+            )
+
+            return banner_text, hidden_content_html
+
+    def _can_user_view_content(self):
+        """
+        Returns whether the runtime user can view the content
+        of this sequential.
+        """
+        return (
+            self.runtime.user_is_staff or
+            self.verify_current_content_visibility(self.due, self.hide_after_due)
+        )
+
+    def _student_view(self, context, banner_text=None):
+        """
+        Returns the rendered student view of the content of this
+        sequential.  If banner_text is given, it is added to the
+        content.
+        """
         display_items = self.get_display_items()
-
-        # If we're rendering this sequence, but no position is set yet,
-        # or exceeds the length of the displayable items,
-        # default the position to the first element
-        if context.get('requested_child') == 'first':
-            self.position = 1
-        elif context.get('requested_child') == 'last':
-            self.position = len(display_items) or 1
-        elif self.position is None or self.position > len(display_items):
-            self.position = 1
-
-        ## Returns a set of all types of all sub-children
-        contents = []
+        self._update_position(context, len(display_items))
 
         fragment = Fragment()
-        context = context or {}
-
-        bookmarks_service = self.runtime.service(self, "bookmarks")
-        context["username"] = self.runtime.service(self, "user").get_current_user().opt_attrs['edx-platform.username']
-
-        parent_module = self.get_parent()
-        display_names = [
-            parent_module.display_name_with_default,
-            self.display_name_with_default
-        ]
-
-        # We do this up here because proctored exam functionality could bypass
-        # rendering after this section.
-        self._capture_basic_metrics()
-
-        # Is this sequential part of a timed or proctored exam?
-        masquerading = context.get('specific_masquerade', False)
-        special_exam_html = None
-        if self.is_time_limited:
-            special_exam_html = self._time_limited_student_view(context)
-
-            # Do we have an applicable alternate rendering
-            # from the edx_proctoring subsystem?
-            if special_exam_html and not masquerading:
-                fragment.add_content(special_exam_html)
-                return fragment
-
-        for child in display_items:
-            is_bookmarked = bookmarks_service.is_bookmarked(usage_key=child.scope_ids.usage_id)
-            context["bookmarked"] = is_bookmarked
-
-            progress = child.get_progress()
-            rendered_child = child.render(STUDENT_VIEW, context)
-            fragment.add_frag_resources(rendered_child)
-
-            childinfo = {
-                'content': rendered_child.content,
-                'page_title': getattr(child, 'tooltip_title', ''),
-                'progress_status': Progress.to_js_status_str(progress),
-                'progress_detail': Progress.to_js_detail_str(progress),
-                'type': child.get_icon_class(),
-                'id': child.scope_ids.usage_id.to_deprecated_string(),
-                'bookmarked': is_bookmarked,
-                'path': " > ".join(display_names + [child.display_name_with_default]),
-            }
-
-            contents.append(childinfo)
-
         params = {
-            'items': contents,
+            'items': self._render_student_view_for_items(context, display_items, fragment),
             'element_id': self.location.html_id(),
             'item_id': self.location.to_deprecated_string(),
             'position': self.position,
@@ -251,17 +270,66 @@ class SequenceModule(SequenceFields, ProctoringFields, XModule):
             'ajax_url': self.system.ajax_url,
             'next_url': context.get('next_url'),
             'prev_url': context.get('prev_url'),
-            'override_hidden_exam': masquerading and special_exam_html is not None,
+            'banner_text': banner_text,
         }
-
         fragment.add_content(self.system.render_template("seq_module.html", params))
 
         self._capture_full_seq_item_metrics(display_items)
         self._capture_current_unit_metrics(display_items)
 
-        # Get all descendant XBlock types and counts
         return fragment
 
+    def _update_position(self, context, number_of_display_items):
+        """
+        Update the user's sequential position given the context and the
+        number_of_display_items
+        """
+        # If we're rendering this sequence, but no position is set yet,
+        # or exceeds the length of the displayable items,
+        # default the position to the first element
+        if context.get('requested_child') == 'first':
+            self.position = 1
+        elif context.get('requested_child') == 'last':
+            self.position = number_of_display_items or 1
+        elif self.position is None or self.position > number_of_display_items:
+            self.position = 1
+
+    def _render_student_view_for_items(self, context, display_items, fragment):
+        """
+        Updates the given fragment with rendered student views of the given
+        display_items.  Returns a list of dict objects with information about
+        the given display_items.
+        """
+        bookmarks_service = self.runtime.service(self, "bookmarks")
+        context["username"] = self.runtime.service(self, "user").get_current_user().opt_attrs['edx-platform.username']
+        display_names = [
+            self.get_parent().display_name_with_default,
+            self.display_name_with_default
+        ]
+        contents = []
+        for item in display_items:
+            is_bookmarked = bookmarks_service.is_bookmarked(usage_key=item.scope_ids.usage_id)
+            context["bookmarked"] = is_bookmarked
+
+            progress = item.get_progress()
+            rendered_item = item.render(STUDENT_VIEW, context)
+            fragment.add_frag_resources(rendered_item)
+
+            iteminfo = {
+                'content': rendered_item.content,
+                'page_title': getattr(item, 'tooltip_title', ''),
+                'progress_status': Progress.to_js_status_str(progress),
+                'progress_detail': Progress.to_js_detail_str(progress),
+                'type': item.get_icon_class(),
+                'id': item.scope_ids.usage_id.to_deprecated_string(),
+                'bookmarked': is_bookmarked,
+                'path': " > ".join(display_names + [item.display_name_with_default]),
+            }
+
+            contents.append(iteminfo)
+
+        return contents
+
     def _locations_in_subtree(self, node):
         """
         The usage keys for all descendants of an XBlock/XModule as a flat list.
@@ -328,7 +396,7 @@ class SequenceModule(SequenceFields, ProctoringFields, XModule):
             for block_type, count in curr_block_counts.items():
                 newrelic.agent.add_custom_parameter('seq.current.block_counts.{}'.format(block_type), count)
 
-    def _time_limited_student_view(self, context):
+    def _time_limited_student_view(self):
         """
         Delegated rendering of a student view when in a time
         limited view. This ultimately calls down into edx_proctoring

common/lib/xmodule/xmodule/tests/test_sequence.py

@@ -2,6 +2,10 @@
 Tests for sequence module.
 """
 # pylint: disable=no-member
+from datetime import timedelta
+import ddt
+from django.utils.timezone import now
+from freezegun import freeze_time
 from mock import Mock
 from xblock.reference.user_service import XBlockUser, UserService
 from xmodule.tests import get_test_system
@@ -24,10 +28,15 @@ class StubUserService(UserService):
         return user
 
 
+@ddt.ddt
 class SequenceBlockTestCase(XModuleXmlImportTest):
     """
     Tests for the Sequence Module.
     """
+    TODAY = now()
+    TOMORROW = TODAY + timedelta(days=1)
+    DAY_AFTER_TOMORROW = TOMORROW + timedelta(days=1)
+
     @classmethod
     def setUpClass(cls):
         super(SequenceBlockTestCase, cls).setUpClass()
@@ -54,13 +63,16 @@ class SequenceBlockTestCase(XModuleXmlImportTest):
         chapter_1 = xml.ChapterFactory.build(parent=course)  # has 2 child sequences
         xml.ChapterFactory.build(parent=course)  # has 0 child sequences
         chapter_3 = xml.ChapterFactory.build(parent=course)  # has 1 child sequence
-        chapter_4 = xml.ChapterFactory.build(parent=course)  # has 2 child sequences
+        chapter_4 = xml.ChapterFactory.build(parent=course)  # has 1 child sequence, with hide_after_due
 
         xml.SequenceFactory.build(parent=chapter_1)
         xml.SequenceFactory.build(parent=chapter_1)
         sequence_3_1 = xml.SequenceFactory.build(parent=chapter_3)  # has 3 verticals
-        xml.SequenceFactory.build(parent=chapter_4)
-        xml.SequenceFactory.build(parent=chapter_4)
+        xml.SequenceFactory.build(  # sequence_4_1
+            parent=chapter_4,
+            hide_after_due=str(True),
+            due=str(cls.TOMORROW),
+        )
 
         for _ in range(3):
             xml.VerticalFactory.build(parent=sequence_3_1)
@@ -98,9 +110,7 @@ class SequenceBlockTestCase(XModuleXmlImportTest):
     def test_render_student_view(self):
         html = self._get_rendered_student_view(
             self.sequence_3_1,
-            requested_child=None,
-            next_url='NextSequential',
-            prev_url='PrevSequential'
+            extra_context=dict(next_url='NextSequential', prev_url='PrevSequential'),
         )
         self._assert_view_at_position(html, expected_position=1)
         self.assertIn(unicode(self.sequence_3_1.location), html)
@@ -115,20 +125,15 @@ class SequenceBlockTestCase(XModuleXmlImportTest):
         html = self._get_rendered_student_view(self.sequence_3_1, requested_child='last')
         self._assert_view_at_position(html, expected_position=3)
 
-    def _get_rendered_student_view(self, sequence, requested_child, next_url=None, prev_url=None):
+    def _get_rendered_student_view(self, sequence, requested_child=None, extra_context=None):
         """
         Returns the rendered student view for the given sequence and the
         requested_child parameter.
         """
-        return sequence.xmodule_runtime.render(
-            sequence,
-            STUDENT_VIEW,
-            {
-                'requested_child': requested_child,
-                'next_url': next_url,
-                'prev_url': prev_url,
-            },
-        ).content
+        context = {'requested_child': requested_child}
+        if extra_context:
+            context.update(extra_context)
+        return sequence.xmodule_runtime.render(sequence, STUDENT_VIEW, context).content
 
     def _assert_view_at_position(self, rendered_html, expected_position):
         """
@@ -140,3 +145,46 @@ class SequenceBlockTestCase(XModuleXmlImportTest):
         html = self._get_rendered_student_view(self.sequence_3_1, requested_child=None)
         for child in self.sequence_3_1.children:
             self.assertIn("'page_title': '{}'".format(child.name), html)
+
+    def test_hidden_content_before_due(self):
+        html = self._get_rendered_student_view(self.sequence_4_1)
+        self.assertIn("seq_module.html", html)
+        self.assertIn("'banner_text': None", html)
+
+    @freeze_time(DAY_AFTER_TOMORROW)
+    @ddt.data(
+        (None, 'subsection'),
+        ('Homework', 'homework'),
+    )
+    @ddt.unpack
+    def test_hidden_content_past_due(self, format_type, expected_text):
+        progress_url = 'http://test_progress_link'
+        self._set_sequence_format(self.sequence_4_1, format_type)
+        html = self._get_rendered_student_view(
+            self.sequence_4_1,
+            extra_context=dict(progress_url=progress_url),
+        )
+        self.assertIn("hidden_content.html", html)
+        self.assertIn(progress_url, html)
+        self.assertIn("'subsection_format': '{}'".format(expected_text), html)
+
+    @freeze_time(DAY_AFTER_TOMORROW)
+    def test_masquerade_hidden_content_past_due(self):
+        self._set_sequence_format(self.sequence_4_1, "Homework")
+        html = self._get_rendered_student_view(
+            self.sequence_4_1,
+            extra_context=dict(specific_masquerade=True),
+        )
+        self.assertIn("seq_module.html", html)
+        self.assertIn(
+            "'banner_text': 'Because the due date has passed, "
+            "this homework is hidden from the learner.'",
+            html
+        )
+
+    def _set_sequence_format(self, sequence, format_type):
+        """
+        Sets the format field on the given sequence to the
+        given value.
+        """
+        sequence._xmodule.format = format_type  # pylint: disable=protected-access

lms/djangoapps/course_api/blocks/api.py

@@ -3,6 +3,7 @@ API function for retrieving course blocks data
 """
 
 from lms.djangoapps.course_blocks.api import get_course_blocks, COURSE_BLOCK_ACCESS_TRANSFORMERS
+from lms.djangoapps.course_blocks.transformers.hidden_content import HiddenContentTransformer
 from openedx.core.lib.block_structure.transformers import BlockStructureTransformers
 
 from .transformers.blocks_api import BlocksAPITransformer
@@ -51,7 +52,7 @@ def get_blocks(
     # create ordered list of transformers, adding BlocksAPITransformer at end.
     transformers = BlockStructureTransformers()
     if user is not None:
-        transformers += COURSE_BLOCK_ACCESS_TRANSFORMERS + [ProctoredExamTransformer()]
+        transformers += COURSE_BLOCK_ACCESS_TRANSFORMERS + [ProctoredExamTransformer(), HiddenContentTransformer()]
     transformers += [
         BlocksAPITransformer(
             block_counts,

lms/djangoapps/course_blocks/api.py

@@ -2,11 +2,8 @@
 API entry point to the course_blocks app with top-level
 get_course_blocks function.
 """
-from django.core.cache import cache
 from openedx.core.djangoapps.content.block_structure.api import get_block_structure_manager
-from openedx.core.lib.block_structure.manager import BlockStructureManager
 from openedx.core.lib.block_structure.transformers import BlockStructureTransformers
-from xmodule.modulestore.django import modulestore
 
 from .transformers import (
     library_content,

lms/djangoapps/course_blocks/transformers/hidden_content.py

@@ -0,0 +1,102 @@
+"""
+Visibility Transformer implementation.
+"""
+from datetime import datetime
+from pytz import utc
+
+from openedx.core.lib.block_structure.transformer import BlockStructureTransformer, FilteringTransformerMixin
+from xmodule.seq_module import SequenceModule
+from .utils import collect_merged_boolean_field, collect_merged_date_field
+
+
+MAXIMUM_DATE = utc.localize(datetime.max)
+
+
+class HiddenContentTransformer(FilteringTransformerMixin, BlockStructureTransformer):
+    """
+    A transformer that enforces the hide_after_due field on
+    blocks by removing children blocks from the block structure for
+    which the user does not have access. The due and hide_after_due
+    fields on a block is percolated down to its descendants, so that
+    all blocks enforce the hidden content settings from their ancestors.
+
+    For a block with multiple parents, access is denied only if
+    access is denied from all its parents.
+
+    Staff users are exempted from hidden content rules.
+    """
+    VERSION = 1
+    MERGED_DUE_DATE = 'merged_due_date'
+    MERGED_HIDE_AFTER_DUE = 'merged_hide_after_due'
+
+    @classmethod
+    def name(cls):
+        """
+        Unique identifier for the transformer's class;
+        same identifier used in setup.py.
+        """
+        return "hidden_content"
+
+    @classmethod
+    def _get_merged_hide_after_due(cls, block_structure, block_key):
+        """
+        Returns whether the block with the given block_key in the
+        given block_structure should be visible to staff only per
+        computed value from ancestry chain.
+        """
+        return block_structure.get_transformer_block_field(
+            block_key, cls, cls.MERGED_HIDE_AFTER_DUE, False
+        )
+
+    @classmethod
+    def _get_merged_due_date(cls, block_structure, block_key):
+        """
+        Returns the merged value for the start date for the block with
+        the given block_key in the given block_structure.
+        """
+        return block_structure.get_transformer_block_field(
+            block_key, cls, cls.MERGED_DUE_DATE, False
+        )
+
+    @classmethod
+    def collect(cls, block_structure):
+        """
+        Collects any information that's necessary to execute this
+        transformer's transform method.
+        """
+        collect_merged_boolean_field(
+            block_structure,
+            transformer=cls,
+            xblock_field_name='hide_after_due',
+            merged_field_name=cls.MERGED_HIDE_AFTER_DUE,
+        )
+
+        collect_merged_date_field(
+            block_structure,
+            transformer=cls,
+            xblock_field_name='due',
+            merged_field_name=cls.MERGED_DUE_DATE,
+            default_date=MAXIMUM_DATE,
+            func_merge_parents=max,
+            func_merge_ancestors=min,
+        )
+
+    def transform_block_filters(self, usage_info, block_structure):
+        # Users with staff access bypass the Visibility check.
+        if usage_info.has_staff_access:
+            return [block_structure.create_universal_filter()]
+
+        return [
+            block_structure.create_removal_filter(
+                lambda block_key: self._is_block_hidden(block_structure, block_key),
+            ),
+        ]
+
+    def _is_block_hidden(self, block_structure, block_key):
+        """
+        Returns whether the block with the given block_key should
+        be hidden, given the current time.
+        """
+        due = self._get_merged_due_date(block_structure, block_key)
+        hide_after_due = self._get_merged_hide_after_due(block_structure, block_key)
+        return not SequenceModule.verify_current_content_visibility(due, hide_after_due)

lms/djangoapps/course_blocks/transformers/start_date.py

@@ -5,7 +5,7 @@ from openedx.core.lib.block_structure.transformer import BlockStructureTransform
 from lms.djangoapps.courseware.access_utils import check_start_date
 from xmodule.course_metadata_utils import DEFAULT_START_DATE
 
-from .utils import get_field_on_block
+from .utils import collect_merged_date_field
 
 
 class StartDateTransformer(FilteringTransformerMixin, BlockStructureTransformer):
@@ -36,7 +36,7 @@ class StartDateTransformer(FilteringTransformerMixin, BlockStructureTransformer)
         return "start_date"
 
     @classmethod
-    def get_merged_start_date(cls, block_structure, block_key):
+    def _get_merged_start_date(cls, block_structure, block_key):
         """
         Returns the merged value for the start date for the block with
         the given block_key in the given block_structure.
@@ -53,35 +53,15 @@ class StartDateTransformer(FilteringTransformerMixin, BlockStructureTransformer)
         """
         block_structure.request_xblock_fields('days_early_for_beta')
 
-        for block_key in block_structure.topological_traversal():
-
-            # compute merged value of start date from all parents
-            parents = block_structure.get_parents(block_key)
-            min_all_parents_start_date = min(
-                cls.get_merged_start_date(block_structure, parent_key)
-                for parent_key in parents
-            ) if parents else None
-
-            # set the merged value for this block
-            block_start = get_field_on_block(block_structure.get_xblock(block_key), 'start')
-            if min_all_parents_start_date is None:
-                # no parents so just use value on block or default
-                merged_start_value = block_start or DEFAULT_START_DATE
-
-            elif not block_start:
-                # no value on this block so take value from parents
-                merged_start_value = min_all_parents_start_date
-
-            else:
-                # max of merged-start-from-all-parents and this block
-                merged_start_value = max(min_all_parents_start_date, block_start)
-
-            block_structure.set_transformer_block_field(
-                block_key,
-                cls,
-                cls.MERGED_START_DATE,
-                merged_start_value
-            )
+        collect_merged_date_field(
+            block_structure,
+            transformer=cls,
+            xblock_field_name='start',
+            merged_field_name=cls.MERGED_START_DATE,
+            default_date=DEFAULT_START_DATE,
+            func_merge_parents=min,
+            func_merge_ancestors=max,
+        )
 
     def transform_block_filters(self, usage_info, block_structure):
         # Users with staff access bypass the Start Date check.
@@ -91,7 +71,7 @@ class StartDateTransformer(FilteringTransformerMixin, BlockStructureTransformer)
         removal_condition = lambda block_key: not check_start_date(
             usage_info.user,
             block_structure.get_xblock_field(block_key, 'days_early_for_beta'),
-            self.get_merged_start_date(block_structure, block_key),
+            self._get_merged_start_date(block_structure, block_key),
             usage_info.course_key,
         )
         return [block_structure.create_removal_filter(removal_condition)]

lms/djangoapps/course_blocks/transformers/tests/helpers.py

@@ -255,7 +255,7 @@ class BlockParentsMapTestCase(TransformerRegistryTestMixin, ModuleStoreTestCase)
             self,
             test_user,
             expected_user_accessible_blocks,
-            blocks_with_differing_access,
+            blocks_with_differing_access=None,
             transformers=None,
     ):
         """
@@ -272,7 +272,8 @@ class BlockParentsMapTestCase(TransformerRegistryTestMixin, ModuleStoreTestCase)
             blocks_with_differing_access (set(int)): Set of
                 blocks (indices) whose access will differ from the
                 transformers result and the current implementation of
-                has_access.
+                has_access.  If not provided, does not compare with
+                has_access results.
 
             transformers (BlockStructureTransformers): An optional collection
                 of transformers that are to be executed.  If not
@@ -312,7 +313,6 @@ class BlockParentsMapTestCase(TransformerRegistryTestMixin, ModuleStoreTestCase)
 
             # compute access results of the block
             block_structure_result = xblock_key in block_structure
-            has_access_result = bool(has_access(user, 'load', self.get_block(i), course_key=self.course.id))
 
             # compare with expected value
             self.assertEquals(
@@ -323,23 +323,25 @@ class BlockParentsMapTestCase(TransformerRegistryTestMixin, ModuleStoreTestCase)
                 )
             )
 
-            # compare with has_access_result
-            if i in blocks_with_differing_access:
-                self.assertNotEqual(
-                    block_structure_result,
-                    has_access_result,
-                    "block structure ({0}) & has_access ({1}) results are equal for block {2} for user {3}".format(
-                        block_structure_result, has_access_result, i, user.username
+            if blocks_with_differing_access:
+                # compare with has_access_result
+                has_access_result = bool(has_access(user, 'load', self.get_block(i), course_key=self.course.id))
+                if i in blocks_with_differing_access:
+                    self.assertNotEqual(
+                        block_structure_result,
+                        has_access_result,
+                        "block structure ({0}) & has_access ({1}) results are equal for block {2} for user {3}".format(
+                            block_structure_result, has_access_result, i, user.username
+                        )
                     )
-                )
-            else:
-                self.assertEquals(
-                    block_structure_result,
-                    has_access_result,
-                    "block structure ({0}) & has_access ({1}) results not equal for block {2} for user {3}".format(
-                        block_structure_result, has_access_result, i, user.username
+                else:
+                    self.assertEquals(
+                        block_structure_result,
+                        has_access_result,
+                        "block structure ({0}) & has_access ({1}) results not equal for block {2} for user {3}".format(
+                            block_structure_result, has_access_result, i, user.username
+                        )
                     )
-                )
 
         self.client.logout()
 

lms/djangoapps/course_blocks/transformers/tests/test_hidden_content.py

@@ -0,0 +1,83 @@
+"""
+Tests for HiddenContentTransformer.
+"""
+from datetime import timedelta
+import ddt
+from django.utils.timezone import now
+from nose.plugins.attrib import attr
+
+from ..hidden_content import HiddenContentTransformer
+from .helpers import BlockParentsMapTestCase, update_block
+
+
+@attr('shard_3')
+@ddt.ddt
+class HiddenContentTransformerTestCase(BlockParentsMapTestCase):
+    """
+    VisibilityTransformer Test
+    """
+    TRANSFORMER_CLASS_TO_TEST = HiddenContentTransformer
+    ALL_BLOCKS = {0, 1, 2, 3, 4, 5, 6}
+
+    class DueDateType(object):
+        """
+        Use constant enum types for deterministic ddt test method names (rather than dynamically generated timestamps)
+        """
+        none = 1,
+        future = 2,
+        past = 3
+
+        TODAY = now()
+        PAST_DATE = TODAY - timedelta(days=30)
+        FUTURE_DATE = TODAY + timedelta(days=30)
+
+        @classmethod
+        def due(cls, enum_value):
+            """
+            Returns a start date for the given enum value
+            """
+            if enum_value == cls.future:
+                return cls.FUTURE_DATE
+            elif enum_value == cls.past:
+                return cls.PAST_DATE
+            else:
+                return None
+
+    # Following test cases are based on BlockParentsMapTestCase.parents_map
+    @ddt.data(
+        ({}, ALL_BLOCKS),
+
+        ({0: DueDateType.none}, ALL_BLOCKS),
+        ({0: DueDateType.future}, ALL_BLOCKS),
+        ({1: DueDateType.none}, ALL_BLOCKS),
+        ({1: DueDateType.future}, ALL_BLOCKS),
+        ({4: DueDateType.none}, ALL_BLOCKS),
+        ({4: DueDateType.future}, ALL_BLOCKS),
+
+        ({0: DueDateType.past}, {}),
+        ({1: DueDateType.past}, ALL_BLOCKS - {1, 3, 4}),
+        ({2: DueDateType.past}, ALL_BLOCKS - {2, 5}),
+        ({4: DueDateType.past}, ALL_BLOCKS - {4}),
+
+        ({1: DueDateType.past, 2: DueDateType.past}, {0}),
+        ({1: DueDateType.none, 2: DueDateType.past}, ALL_BLOCKS - {2, 5}),
+        ({1: DueDateType.past, 2: DueDateType.none}, ALL_BLOCKS - {1, 3, 4}),
+    )
+    @ddt.unpack
+    def test_hidden_content(
+            self,
+            hide_due_values,
+            expected_visible_blocks,
+    ):
+        for idx, due_date_type in hide_due_values.iteritems():
+            block = self.get_block(idx)
+            block.due = self.DueDateType.due(due_date_type)
+            block.hide_after_due = True
+            update_block(block)
+
+        self.assert_transform_results(
+            self.student,
+            expected_visible_blocks,
+            blocks_with_differing_access=None,
+            transformers=self.transformers,
+        )

lms/djangoapps/course_blocks/transformers/utils.py

@@ -10,7 +10,103 @@ def get_field_on_block(block, field_name, default_value=None):
     returns value from only a single parent chain
     (e.g., doesn't take a union in DAGs).
     """
-    if block.fields[field_name].is_set_on(block):
-        return getattr(block, field_name)
-    else:
-        return default_value
+    try:
+        if block.fields[field_name].is_set_on(block):
+            return getattr(block, field_name)
+    except KeyError:
+        pass
+    return default_value
+
+
+def collect_merged_boolean_field(
+        block_structure,
+        transformer,
+        xblock_field_name,
+        merged_field_name,
+):
+    """
+    Collects a boolean xBlock field of name xblock_field_name
+    for the given block_structure and transformer.  The boolean
+    value is percolated down the hierarchy of the block_structure
+    and stored as a value of merged_field_name in the
+    block_structure.
+
+    Assumes that the boolean field is False, by default. So,
+    the value is ANDed across all parents for blocks with
+    multiple parents and ORed across all ancestors down a single
+    hierarchy chain.
+    """
+
+    for block_key in block_structure.topological_traversal():
+        # compute merged value of the boolean field from all parents
+        parents = block_structure.get_parents(block_key)
+        all_parents_merged_value = all(  # pylint: disable=invalid-name
+            block_structure.get_transformer_block_field(
+                parent_key, transformer, merged_field_name, False,
+            )
+            for parent_key in parents
+        ) if parents else False
+
+        # set the merged value for this block
+        block_structure.set_transformer_block_field(
+            block_key,
+            transformer,
+            merged_field_name,
+            (
+                all_parents_merged_value or
+                get_field_on_block(
+                    block_structure.get_xblock(block_key), xblock_field_name,
+                    False,
+                )
+            )
+        )
+
+
+def collect_merged_date_field(
+        block_structure,
+        transformer,
+        xblock_field_name,
+        merged_field_name,
+        default_date,
+        func_merge_parents=min,
+        func_merge_ancestors=max,
+):
+    """
+    Collects a date xBlock field of name xblock_field_name
+    for the given block_structure and transformer.  The date
+    value is percolated down the hierarchy of the block_structure
+    and stored as a value of merged_field_name in the
+    block_structure.
+    """
+
+    for block_key in block_structure.topological_traversal():
+
+        parents = block_structure.get_parents(block_key)
+        block_date = get_field_on_block(block_structure.get_xblock(block_key), xblock_field_name)
+        if not parents:
+            # no parents so just use value on block or default
+            merged_date_value = block_date or default_date
+
+        else:
+            # compute merged value of date from all parents
+            merged_all_parents_date = func_merge_parents(
+                block_structure.get_transformer_block_field(
+                    parent_key, transformer, merged_field_name, default_date,
+                )
+                for parent_key in parents
+            )
+
+            if not block_date:
+                # no value on this block so take value from parents
+                merged_date_value = merged_all_parents_date
+
+            else:
+                # compute merged date of the block and the parent
+                merged_date_value = func_merge_ancestors(merged_all_parents_date, block_date)
+
+        block_structure.set_transformer_block_field(
+            block_key,
+            transformer,
+            merged_field_name,
+            merged_date_value
+        )

lms/djangoapps/course_blocks/transformers/visibility.py

@@ -2,6 +2,7 @@
 Visibility Transformer implementation.
 """
 from openedx.core.lib.block_structure.transformer import BlockStructureTransformer, FilteringTransformerMixin
+from .utils import collect_merged_boolean_field
 
 
 class VisibilityTransformer(FilteringTransformerMixin, BlockStructureTransformer):
@@ -30,7 +31,7 @@ class VisibilityTransformer(FilteringTransformerMixin, BlockStructureTransformer
         return "visibility"
 
     @classmethod
-    def get_visible_to_staff_only(cls, block_structure, block_key):
+    def _get_visible_to_staff_only(cls, block_structure, block_key):
         """
         Returns whether the block with the given block_key in the
         given block_structure should be visible to staff only per
@@ -46,26 +47,12 @@ class VisibilityTransformer(FilteringTransformerMixin, BlockStructureTransformer
         Collects any information that's necessary to execute this
         transformer's transform method.
         """
-        for block_key in block_structure.topological_traversal():
-
-            # compute merged value of visible_to_staff_only from all parents
-            parents = block_structure.get_parents(block_key)
-            all_parents_visible_to_staff_only = all(  # pylint: disable=invalid-name
-                cls.get_visible_to_staff_only(block_structure, parent_key)
-                for parent_key in parents
-            ) if parents else False
-
-            # set the merged value for this block
-            block_structure.set_transformer_block_field(
-                block_key,
-                cls,
-                cls.MERGED_VISIBLE_TO_STAFF_ONLY,
-                # merge visible_to_staff_only from all parents and this block
-                (
-                    all_parents_visible_to_staff_only or
-                    block_structure.get_xblock(block_key).visible_to_staff_only
-                )
-            )
+        collect_merged_boolean_field(
+            block_structure,
+            transformer=cls,
+            xblock_field_name='visible_to_staff_only',
+            merged_field_name=cls.MERGED_VISIBLE_TO_STAFF_ONLY,
+        )
 
     def transform_block_filters(self, usage_info, block_structure):
         # Users with staff access bypass the Visibility check.
@@ -74,6 +61,6 @@ class VisibilityTransformer(FilteringTransformerMixin, BlockStructureTransformer
 
         return [
             block_structure.create_removal_filter(
-                lambda block_key: self.get_visible_to_staff_only(block_structure, block_key),
+                lambda block_key: self._get_visible_to_staff_only(block_structure, block_key),
             )
         ]

lms/djangoapps/courseware/views/index.py

@@ -447,7 +447,7 @@ class CoursewareIndex(View):
             return "{url}?child={requested_child}".format(
                 url=reverse(
                     'courseware_section',
-                    args=[unicode(self.course.id), section_info['chapter_url_name'], section_info['url_name']],
+                    args=[unicode(self.course_key), section_info['chapter_url_name'], section_info['url_name']],
                 ),
                 requested_child=requested_child,
             )
@@ -455,6 +455,7 @@ class CoursewareIndex(View):
         section_context = {
             'activate_block_id': self.request.GET.get('activate_block_id'),
             'requested_child': self.request.GET.get("child"),
+            'progress_url': reverse('progress', kwargs={'course_id': unicode(self.course_key)}),
         }
         if previous_of_active_section:
             section_context['prev_url'] = _compute_section_url(previous_of_active_section, 'last')

lms/templates/hidden_content.html

@@ -0,0 +1,26 @@
+<%page expression_filter="h"/>
+<%!
+from django.utils.translation import ugettext as _
+from openedx.core.djangolib.markup import HTML, Text
+%>
+
+<div class="sequence hidden-content proctored-exam completed">
+  <h3>
+      ${_("The due date for this {subsection_format} has passed.").format(
+        subsection_format=subsection_format,
+      )}
+  </h3>
+  <hr>
+  <p>
+      ${Text(_(
+          "Because the due date has passed, this {subsection_format} "
+          "is no longer available.{line_break}If you have completed this {subsection_format}, "
+          "your grade is available on the {link_start}progress page{link_end}."
+        )).format(
+          subsection_format=subsection_format,
+          line_break=HTML("<br>"),
+          link_start=HTML("<a href='{}'>").format(progress_url),
+          link_end=HTML("</a>"),
+      )}
+  </p>
+</div>

lms/templates/seq_module.html

@@ -3,12 +3,12 @@
 
 <div id="sequence_${element_id}" class="sequence" data-id="${item_id}" data-position="${position}" data-ajax-url="${ajax_url}" data-next-url="${next_url}" data-prev-url="${prev_url}">
   <div class="path"></div>
-    % if override_hidden_exam:
+    % if banner_text:
       <div class="pattern-library-shim alert alert-information subsection-header" tabindex="-1">
         <span class="pattern-library-shim icon alert-icon fa fa-bullhorn" aria-hidden="true"></span>
         <div class="pattern-library-shim alert-message">
           <p class="pattern-library-shim alert-copy">
-            ${_("This exam is hidden from the learner.")}
+            ${banner_text}
           </p>
         </div>
       </div>

setup.py

@@ -49,6 +49,7 @@ setup(
             "start_date = lms.djangoapps.course_blocks.transformers.start_date:StartDateTransformer",
             "user_partitions = lms.djangoapps.course_blocks.transformers.user_partitions:UserPartitionTransformer",
             "visibility = lms.djangoapps.course_blocks.transformers.visibility:VisibilityTransformer",
+            "hidden_content = lms.djangoapps.course_blocks.transformers.hidden_content:HiddenContentTransformer",
             "course_blocks_api = lms.djangoapps.course_api.blocks.transformers.blocks_api:BlocksAPITransformer",
             "proctored_exam = lms.djangoapps.course_api.blocks.transformers.proctored_exam:ProctoredExamTransformer",
             "grades = lms.djangoapps.courseware.transformers.grades:GradesTransformer",