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