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52 lines
1.7 KiB
52 lines
1.7 KiB
"""Handle Model Serialization."""
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from typing import Dict, Callable, Any, List, Optional, Type
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from atheneum import errors
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from atheneum.db import db
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class BaseSerializer: # pylint: disable=too-few-public-methods
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"""Base Model serializer."""
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def __init__(self, model: Type[db.Model]) -> None:
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"""Initialize the base serializer."""
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self._fields: Dict[str, Callable[[db.Model], Any]] = {}
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self.model = model
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def serialize(self, options: Optional[List[str]]) -> Any:
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"""Convert Model field and factories to dicts."""
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field_factories = self._serializers()
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if not options:
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options = list(field_factories.keys())
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ret = {}
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for key in options:
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if key not in field_factories:
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raise errors.ValidationError(
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'Invalid key: %r. Valid keys: %r.' % (
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key, list(sorted(field_factories.keys()))))
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factory = field_factories[key]
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ret[key] = factory()
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return ret
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def _serializers(self) -> Dict[str, Callable[[], Any]]:
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"""Field definitions."""
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raise NotImplementedError()
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_model_serializers: Dict[str, Type[BaseSerializer]] = {}
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def register_serializer(
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model_name: str, model_serializer: Type[BaseSerializer]) -> None:
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"""Add a model to the serializer mapping."""
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_model_serializers[model_name] = model_serializer
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def serialize_model(model_obj: db.Model) -> Any:
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"""Lookup a Model and hand off to the serializer."""
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try:
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return _model_serializers[
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type(model_obj).__name__](model_obj).serialize(None)
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except KeyError:
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raise NotImplementedError(
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'{} has no registered serializers'.format(model_obj.__name__))
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