23 lines
1.1 KiB
Python
23 lines
1.1 KiB
Python
"""Fields useful for edX API implementations."""
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from rest_framework.serializers import Field
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class ExpandableField(Field):
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"""Field that can dynamically use a more detailed serializer based on a user-provided "expand" parameter."""
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def __init__(self, **kwargs):
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"""Sets up the ExpandableField with the collapsed and expanded versions of the serializer."""
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assert 'collapsed_serializer' in kwargs and 'expanded_serializer' in kwargs
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self.collapsed = kwargs.pop('collapsed_serializer')
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self.expanded = kwargs.pop('expanded_serializer')
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super(ExpandableField, self).__init__(**kwargs)
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def field_to_native(self, obj, field_name):
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"""Converts obj to a native representation, using the expanded serializer if the context requires it."""
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if 'expand' in self.context and field_name in self.context['expand']:
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self.expanded.initialize(self, field_name)
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return self.expanded.field_to_native(obj, field_name)
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else:
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self.collapsed.initialize(self, field_name)
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return self.collapsed.field_to_native(obj, field_name)
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