69410948c9
This change improves grading performance by combining what had previously been multiple course tree traversals into a single traversal with combined filtering logic.
80 lines
2.9 KiB
Python
80 lines
2.9 KiB
Python
"""
|
|
Visibility Transformer implementation.
|
|
"""
|
|
from openedx.core.lib.block_structure.transformer import BlockStructureTransformer, FilteringTransformerMixin
|
|
|
|
|
|
class VisibilityTransformer(FilteringTransformerMixin, BlockStructureTransformer):
|
|
"""
|
|
A transformer that enforces the visible_to_staff_only field on
|
|
blocks by removing blocks from the block structure for which the
|
|
user does not have access. The visible_to_staff_only field on a
|
|
block is percolated down to its descendants, so that all blocks
|
|
enforce the visibility settings from their ancestors.
|
|
|
|
For a block with multiple parents, access is denied only if
|
|
visibility is denied for all its parents.
|
|
|
|
Staff users are exempted from visibility rules.
|
|
"""
|
|
VERSION = 1
|
|
|
|
MERGED_VISIBLE_TO_STAFF_ONLY = 'merged_visible_to_staff_only'
|
|
|
|
@classmethod
|
|
def name(cls):
|
|
"""
|
|
Unique identifier for the transformer's class;
|
|
same identifier used in setup.py.
|
|
"""
|
|
return "visibility"
|
|
|
|
@classmethod
|
|
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
|
|
computed value from ancestry chain.
|
|
"""
|
|
return block_structure.get_transformer_block_field(
|
|
block_key, cls, cls.MERGED_VISIBLE_TO_STAFF_ONLY, False
|
|
)
|
|
|
|
@classmethod
|
|
def collect(cls, block_structure):
|
|
"""
|
|
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
|
|
)
|
|
)
|
|
|
|
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.get_visible_to_staff_only(block_structure, block_key),
|
|
)
|
|
]
|