HiddenContentTransformer to check for hide_after_due

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

+"""
+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

+"""
+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),
             )
         ]

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",