44 lines
1.4 KiB
Python
44 lines
1.4 KiB
Python
"""
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Hide Empty Transformer implementation.
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"""
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# TODO: Remove this file after REVE-52 lands and old-mobile-app traffic falls to < 5% of mobile traffic
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from __future__ import absolute_import
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from openedx.core.djangoapps.content.block_structure.transformer import BlockStructureTransformer
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class HideEmptyTransformer(BlockStructureTransformer):
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"""
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A transformer that removes any block from the course that could have
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children but doesn't.
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"""
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WRITE_VERSION = 1
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READ_VERSION = 1
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@classmethod
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def name(cls):
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"""
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Unique identifier for the transformer's class;
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same identifier used in setup.py.
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"""
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return "hide_empty"
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@classmethod
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def collect(cls, block_structure):
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"""
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Collects any information that's necessary to execute this
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transformer's transform method.
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"""
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block_structure.request_xblock_fields('children', 'has_children')
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def transform(self, usage_info, block_structure):
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def _filter(block_key):
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has_children = block_structure.get_xblock_field(block_key, 'has_children')
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children = block_structure.get_xblock_field(block_key, 'children')
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return has_children and not any(child in block_structure for child in children)
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for _ in block_structure.post_order_traversal(
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filter_func=block_structure.create_removal_filter(_filter)
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):
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pass
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