""" Content Library Transformer. """ import json import logging from eventtracking import tracker from common.djangoapps.track import contexts from lms.djangoapps.courseware.models import StudentModule from openedx.core.djangoapps.content.block_structure.transformer import ( BlockStructureTransformer, FilteringTransformerMixin ) from xmodule.library_content_module import LibraryContentBlock from xmodule.modulestore.django import modulestore from ..utils import get_student_module_as_dict logger = logging.getLogger(__name__) class ContentLibraryTransformer(FilteringTransformerMixin, BlockStructureTransformer): """ A transformer that manipulates the block structure by removing all blocks within a library_content module to which a user should not have access. Staff users are not to be 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" @classmethod def collect(cls, block_structure): """ Collects any information that's necessary to execute this transformer's transform method. """ block_structure.request_xblock_fields('mode') block_structure.request_xblock_fields('max_count') block_structure.request_xblock_fields('category') store = modulestore() # needed for analytics purposes def summarize_block(usage_key): """ Basic information about the given block """ orig_key, orig_version = store.get_block_original_usage(usage_key) return { "usage_key": str(usage_key), "original_usage_key": str(orig_key) if orig_key else None, "original_usage_version": str(orig_version) if orig_version else None, } # For each block check if block is library_content. # If library_content add children array to content_library_children field for block_key in block_structure.topological_traversal( filter_func=lambda block_key: block_key.block_type == 'library_content', yield_descendants_of_unyielded=True, ): xblock = block_structure.get_xblock(block_key) for child_key in xblock.children: summary = summarize_block(child_key) block_structure.set_transformer_block_field(child_key, cls, 'block_analytics_summary', summary) def transform_block_filters(self, usage_info, block_structure): all_library_children = set() all_selected_children = set() for block_key in block_structure: if block_key.block_type != 'library_content': continue library_children = block_structure.get_children(block_key) if library_children: all_library_children.update(library_children) selected = [] mode = block_structure.get_xblock_field(block_key, 'mode') max_count = block_structure.get_xblock_field(block_key, 'max_count') # Retrieve "selected" json from LMS MySQL database. 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. block_type, block_id = selected_block usage_key = usage_info.course_key.make_usage_key(block_type, block_id) if usage_key in library_children: selected.append(selected_block) # Update selected previous_count = len(selected) block_keys = LibraryContentBlock.make_selection(selected, library_children, max_count, mode) selected = block_keys['selected'] # Save back any changes if any(block_keys[changed] for changed in ('invalid', 'overlimit', 'added')): state_dict['selected'] = selected StudentModule.save_state( student=usage_info.user, course_id=usage_info.course_key, module_state_key=block_key, defaults={ 'state': json.dumps(state_dict), }, ) # publish events for analytics self._publish_events( block_structure, block_key, previous_count, max_count, block_keys, usage_info.user.id, ) all_selected_children.update(usage_info.course_key.make_usage_key(s[0], s[1]) for s in selected) def check_child_removal(block_key): """ Return True if selected block should be removed. Block is removed if it is part of library_content, but has not been selected for current user. """ if block_key not in all_library_children: return False if block_key in all_selected_children: return False return True return [block_structure.create_removal_filter(check_child_removal)] def _publish_events(self, block_structure, location, previous_count, max_count, block_keys, user_id): """ Helper method to publish events for analytics purposes """ def format_block_keys(keys): """ Helper function to format block keys """ json_result = [] for key in keys: info = block_structure.get_transformer_block_field( key, ContentLibraryTransformer, 'block_analytics_summary' ) json_result.append(info) return json_result def publish_event(event_name, result, **kwargs): """ Helper function to publish an event for analytics purposes """ event_data = { "location": str(location), "previous_count": previous_count, "result": result, "max_count": max_count, } event_data.update(kwargs) context = contexts.course_context_from_course_id(location.course_key) if user_id: context['user_id'] = user_id full_event_name = f"edx.librarycontentblock.content.{event_name}" with tracker.get_tracker().context(full_event_name, context): tracker.emit(full_event_name, event_data) LibraryContentBlock.publish_selected_children_events( block_keys, 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 # pylint:disable=unnecessary-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 library_children = block_structure.get_children(block_key) if library_children: state_dict = get_student_module_as_dict(usage_info.user, usage_info.course_key, block_key) current_children_blocks = {block.block_id for block in library_children} current_selected_blocks = {item[1] for item in state_dict['selected']} # As the selections should have already been made by the ContentLibraryTransformer, # the current children of the library_content block should be the same as the stored # selections. If they aren't, some other transformer that ran before this transformer # has modified those blocks (for example, content gating may have affected this). So do not # transform the order in that case. if current_children_blocks != current_selected_blocks: logger.debug( 'Mismatch between the children of %s in the stored state and the actual children for user %s. ' 'Continuing without order transformation.', str(block_key), usage_info.user.username ) else: 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])