From 73ab30e3421fbaf042b168bd75235dc539c11fd6 Mon Sep 17 00:00:00 2001 From: Guruprasad Lakshmi Narayanan Date: Mon, 23 Jul 2018 13:37:04 +0530 Subject: [PATCH] Fix the order randomization behaviour of Randomized Content Block The Randomized Content Block XBlock only randomizes the selection of the children blocks and has unpredictable randomization of the order of the selected child blocks due to the usage of sets, which are unordered, for storing the selected blocks. This becomes apparent when all the available child blocks in a library are chosen for a Randomized Content Block, to randomize just the order of the child blocks and not just the selection of the blocks. The order of the selected blocks ends up being similar for multiple learners. This change modifies the XBlock to store the selected child blocks in a list, instead of a set, after randomly shuffling them. --- .../xmodule/xmodule/library_content_module.py | 43 +++--- .../xmodule/tests/test_library_content.py | 13 +- lms/djangoapps/course_blocks/api.py | 1 + .../transformers/library_content.py | 47 +++++++ .../tests/test_library_content.py | 130 +++++++++++++++++- setup.py | 1 + 6 files changed, 201 insertions(+), 34 deletions(-) diff --git a/common/lib/xmodule/xmodule/library_content_module.py b/common/lib/xmodule/xmodule/library_content_module.py index 13e505dc8b..66ca2bb26d 100644 --- a/common/lib/xmodule/xmodule/library_content_module.py +++ b/common/lib/xmodule/xmodule/library_content_module.py @@ -154,37 +154,40 @@ class LibraryContentModule(LibraryContentFields, XModule, StudioEditableModule): """ rand = random.Random() - selected = set(tuple(k) for k in selected) # set of (block_type, block_id) tuples assigned to this student + selected_keys = set(tuple(k) for k in selected) # set of (block_type, block_id) tuples assigned to this student # Determine which of our children we will show: valid_block_keys = set([(c.block_type, c.block_id) for c in children]) # Remove any selected blocks that are no longer valid: - invalid_block_keys = (selected - valid_block_keys) + invalid_block_keys = (selected_keys - valid_block_keys) if invalid_block_keys: - selected -= invalid_block_keys + selected_keys -= invalid_block_keys # If max_count has been decreased, we may have to drop some previously selected blocks: overlimit_block_keys = set() - if len(selected) > max_count: - num_to_remove = len(selected) - max_count - overlimit_block_keys = set(rand.sample(selected, num_to_remove)) - selected -= overlimit_block_keys + if len(selected_keys) > max_count: + num_to_remove = len(selected_keys) - max_count + overlimit_block_keys = set(rand.sample(selected_keys, num_to_remove)) + selected_keys -= overlimit_block_keys # Do we have enough blocks now? - num_to_add = max_count - len(selected) + num_to_add = max_count - len(selected_keys) added_block_keys = None if num_to_add > 0: # We need to select [more] blocks to display to this user: - pool = valid_block_keys - selected + pool = valid_block_keys - selected_keys if mode == "random": num_to_add = min(len(pool), num_to_add) added_block_keys = set(rand.sample(pool, num_to_add)) # We now have the correct n random children to show for this user. else: raise NotImplementedError("Unsupported mode.") - selected |= added_block_keys + selected_keys |= added_block_keys + + if any([invalid_block_keys, overlimit_block_keys, added_block_keys]): + selected = selected_keys return { 'selected': selected, @@ -264,19 +267,15 @@ class LibraryContentModule(LibraryContentFields, XModule, StudioEditableModule): def selected_children(self): """ - Returns a set() of block_ids indicating which of the possible children + Returns a list() of block_ids indicating which of the possible children have been selected to display to the current user. This reads and updates the "selected" field, which has user_state scope. - Note: self.selected and the return value contain block_ids. To get + Note: the return value (self.selected) contains block_ids. To get actual BlockUsageLocators, it is necessary to use self.children, because the block_ids alone do not specify the block type. """ - if hasattr(self, "_selected_set"): - # Already done: - return self._selected_set # pylint: disable=access-member-before-definition - block_keys = self.make_selection(self.selected, self.children, self.max_count, "random") # pylint: disable=no-member # Publish events for analytics purposes: @@ -288,13 +287,13 @@ class LibraryContentModule(LibraryContentFields, XModule, StudioEditableModule): self._publish_event, ) - # Save our selections to the user state, to ensure consistency: - selected = block_keys['selected'] - self.selected = list(selected) # TODO: this doesn't save from the LMS "Progress" page. - # Cache the results - self._selected_set = selected # pylint: disable=attribute-defined-outside-init + if any(block_keys[changed] for changed in ('invalid', 'overlimit', 'added')): + # Save our selections to the user state, to ensure consistency: + selected = list(block_keys['selected']) + random.shuffle(selected) + self.selected = selected # TODO: this doesn't save from the LMS "Progress" page. - return selected + return self.selected def _get_selected_child_blocks(self): """ diff --git a/common/lib/xmodule/xmodule/tests/test_library_content.py b/common/lib/xmodule/xmodule/tests/test_library_content.py index f3a34d7512..b23705d8c7 100644 --- a/common/lib/xmodule/xmodule/tests/test_library_content.py +++ b/common/lib/xmodule/xmodule/tests/test_library_content.py @@ -269,9 +269,8 @@ class LibraryContentModuleTestMixin(object): Helper method that changes the max_count of self.lc_block, refreshes children, and asserts that the number of selected children equals the count provided. """ - # Clear the cache (only needed because we skip saving/re-loading the block) pylint: disable=protected-access - if hasattr(self.lc_block._xmodule, '_selected_set'): - del self.lc_block._xmodule._selected_set + # Construct the XModule for the descriptor, if not present already present pylint: disable=protected-access + self.lc_block._xmodule self.lc_block.max_count = count selected = self.lc_block.get_child_descriptors() self.assertEqual(len(selected), count) @@ -394,8 +393,6 @@ class TestLibraryContentAnalytics(LibraryContentTest): # Now increase max_count so that one more child will be added: self.lc_block.max_count = 2 - # Clear the cache (only needed because we skip saving/re-loading the block) pylint: disable=protected-access - del self.lc_block._xmodule._selected_set children = self.lc_block.get_child_descriptors() self.assertEqual(len(children), 2) child, new_child = children if children[0].location == child.location else reversed(children) @@ -475,8 +472,6 @@ class TestLibraryContentAnalytics(LibraryContentTest): self.lc_block.get_child_descriptors() # This line is needed in the test environment or the change has no effect self.publisher.reset_mock() # Clear the "assigned" event that was just published. self.lc_block.max_count = 0 - # Clear the cache (only needed because we skip saving/re-loading the block) pylint: disable=protected-access - del self.lc_block._xmodule._selected_set # Check that the event says that one block was removed, leaving no blocks left: children = self.lc_block.get_child_descriptors() @@ -494,8 +489,6 @@ class TestLibraryContentAnalytics(LibraryContentTest): # Start by assigning two blocks to the student: self.lc_block.get_child_descriptors() # This line is needed in the test environment or the change has no effect self.lc_block.max_count = 2 - # Clear the cache (only needed because we skip saving/re-loading the block) pylint: disable=protected-access - del self.lc_block._xmodule._selected_set initial_blocks_assigned = self.lc_block.get_child_descriptors() self.assertEqual(len(initial_blocks_assigned), 2) self.publisher.reset_mock() # Clear the "assigned" event that was just published. @@ -509,8 +502,6 @@ class TestLibraryContentAnalytics(LibraryContentTest): self.library.children = [keep_block_lib_usage_key] self.store.update_item(self.library, self.user_id) self.lc_block.refresh_children() - # Clear the cache (only needed because we skip saving/re-loading the block) pylint: disable=protected-access - del self.lc_block._xmodule._selected_set # Check that the event says that one block was removed, leaving one block left: children = self.lc_block.get_child_descriptors() diff --git a/lms/djangoapps/course_blocks/api.py b/lms/djangoapps/course_blocks/api.py index e7139b64b1..fa0ce68424 100644 --- a/lms/djangoapps/course_blocks/api.py +++ b/lms/djangoapps/course_blocks/api.py @@ -42,6 +42,7 @@ def get_course_block_access_transformers(user): """ course_block_access_transformers = [ library_content.ContentLibraryTransformer(), + library_content.ContentLibraryOrderTransformer(), start_date.StartDateTransformer(), ContentTypeGateTransformer(), user_partitions.UserPartitionTransformer(), diff --git a/lms/djangoapps/course_blocks/transformers/library_content.py b/lms/djangoapps/course_blocks/transformers/library_content.py index e566a1a0c7..5778292312 100644 --- a/lms/djangoapps/course_blocks/transformers/library_content.py +++ b/lms/djangoapps/course_blocks/transformers/library_content.py @@ -2,6 +2,7 @@ Content Library Transformer. """ import json +import random from courseware.models import StudentModule from eventtracking import tracker @@ -98,6 +99,7 @@ class ContentLibraryTransformer(FilteringTransformerMixin, BlockStructureTransfo # Save back any changes if any(block_keys[changed] for changed in ('invalid', 'overlimit', 'added')): state_dict['selected'] = list(selected) + random.shuffle(state_dict['selected']) StudentModule.save_state( # pylint: disable=no-value-for-parameter student=usage_info.user, course_id=usage_info.course_key, @@ -175,3 +177,48 @@ class ContentLibraryTransformer(FilteringTransformerMixin, BlockStructureTransfo format_block_keys, publish_event, ) + + +class ContentLibraryOrderTransformer(BlockStructureTransformer): + """ + A transformer that manipulates the block structure by modifying the order of the + selected blocks within a library_content module to match the order of the selections + made by the ContentLibraryTransformer or the corresponding XBlock. So this transformer + requires the selections for the randomized content block to be already + made either by the ContentLibraryTransformer or the XBlock. + + Staff users are *not* exempted from library content pathways/ + """ + WRITE_VERSION = 1 + READ_VERSION = 1 + + @classmethod + def name(cls): + """ + Unique identifier for the transformer's class; + same identifier used in setup.py + """ + return "library_content_randomize" + + @classmethod + def collect(cls, block_structure): + """ + Collects any information that's necessary to execute this + transformer's transform method. + """ + # There is nothing to collect. + pass + + def transform(self, usage_info, block_structure): + """ + Transforms the order of the children of the randomized content block + to match the order of the selections made and stored in the XBlock 'selected' field. + """ + for block_key in block_structure: + if block_key.block_type != 'library_content': + continue + + state_dict = get_student_module_as_dict(usage_info.user, usage_info.course_key, block_key) + library_children = block_structure.get_children(block_key) + ordering_data = {block[1]: position for position, block in enumerate(state_dict['selected'])} + library_children.sort(key=lambda block, data=ordering_data: data[block.block_id]) diff --git a/lms/djangoapps/course_blocks/transformers/tests/test_library_content.py b/lms/djangoapps/course_blocks/transformers/tests/test_library_content.py index 44b0c1ea92..815a3ada75 100644 --- a/lms/djangoapps/course_blocks/transformers/tests/test_library_content.py +++ b/lms/djangoapps/course_blocks/transformers/tests/test_library_content.py @@ -1,13 +1,14 @@ """ Tests for ContentLibraryTransformer. """ +import mock from openedx.core.djangoapps.content.block_structure.api import clear_course_from_cache from openedx.core.djangoapps.content.block_structure.transformers import BlockStructureTransformers from student.tests.factories import CourseEnrollmentFactory from ...api import get_course_blocks -from ..library_content import ContentLibraryTransformer +from ..library_content import ContentLibraryTransformer, ContentLibraryOrderTransformer from .helpers import CourseStructureTestCase @@ -180,3 +181,130 @@ class ContentLibraryTransformerTestCase(CourseStructureTestCase): transformers=self.transformers ) self.assertEqual(len(list(transformed_blocks.get_block_keys())), len(self.blocks)) + + +class ContentLibraryOrderTransformerTestCase(CourseStructureTestCase): + """ + ContentLibraryOrderTransformer Test + """ + TRANSFORMER_CLASS_TO_TEST = ContentLibraryOrderTransformer + + def setUp(self): + """ + Setup course structure and create user for content library order transformer test. + """ + super(ContentLibraryOrderTransformerTestCase, self).setUp() + self.course_hierarchy = self.get_course_hierarchy() + self.blocks = self.build_course(self.course_hierarchy) + self.course = self.blocks['course'] + clear_course_from_cache(self.course.id) + + # Enroll user in course. + CourseEnrollmentFactory.create(user=self.user, course_id=self.course.id, is_active=True) + + def get_course_hierarchy(self): + """ + Get a course hierarchy to test with. + """ + return [{ + 'org': 'ContentLibraryTransformer', + 'course': 'CL101F', + 'run': 'test_run', + '#type': 'course', + '#ref': 'course', + '#children': [ + { + '#type': 'chapter', + '#ref': 'chapter1', + '#children': [ + { + '#type': 'sequential', + '#ref': 'lesson1', + '#children': [ + { + '#type': 'vertical', + '#ref': 'vertical1', + '#children': [ + { + 'metadata': {'category': 'library_content'}, + '#type': 'library_content', + '#ref': 'library_content1', + '#children': [ + { + 'metadata': {'display_name': "CL Vertical 2"}, + '#type': 'vertical', + '#ref': 'vertical2', + '#children': [ + { + 'metadata': {'display_name': "HTML1"}, + '#type': 'html', + '#ref': 'html1', + } + ] + }, + { + 'metadata': {'display_name': "CL Vertical 3"}, + '#type': 'vertical', + '#ref': 'vertical3', + '#children': [ + { + 'metadata': {'display_name': "HTML2"}, + '#type': 'html', + '#ref': 'html2', + } + ] + }, + { + 'metadata': {'display_name': "CL Vertical 4"}, + '#type': 'vertical', + '#ref': 'vertical4', + '#children': [ + { + 'metadata': {'display_name': "HTML3"}, + '#type': 'html', + '#ref': 'html3', + } + ] + } + ] + } + ], + } + ], + } + ], + } + ] + }] + + @mock.patch('lms.djangoapps.course_blocks.transformers.library_content.get_student_module_as_dict') + def test_content_library_randomize(self, mocked): + """ + Test whether the order of the children blocks matches the order of the selected blocks when + course has content library section + """ + mocked.return_value = { + 'selected': [ + ['vertical', 'vertical_vertical3'], + ['vertical', 'vertical_vertical2'], + ['vertical', 'vertical_vertical4'], + ] + } + for i in range(5): + trans_block_structure = get_course_blocks( + self.user, + self.course.location, + self.transformers, + ) + children = [] + for block_key in trans_block_structure.topological_traversal(): + if block_key.block_type == 'library_content': + children = trans_block_structure.get_children(block_key) + break + + expected_children = ['vertical_vertical3', 'vertical_vertical2', 'vertical_vertical4'] + self.assertEqual( + expected_children, + [child.block_id for child in children], + u"Expected 'selected' equality failed in iteration {}.".format(i) + ) diff --git a/setup.py b/setup.py index 0088a6fe23..0a1f0dac05 100644 --- a/setup.py +++ b/setup.py @@ -51,6 +51,7 @@ setup( ], "openedx.block_structure_transformer": [ "library_content = lms.djangoapps.course_blocks.transformers.library_content:ContentLibraryTransformer", + "library_content_randomize = lms.djangoapps.course_blocks.transformers.library_content:ContentLibraryOrderTransformer", "split_test = lms.djangoapps.course_blocks.transformers.split_test:SplitTestTransformer", "start_date = lms.djangoapps.course_blocks.transformers.start_date:StartDateTransformer", "user_partitions = lms.djangoapps.course_blocks.transformers.user_partitions:UserPartitionTransformer",