Source code for classical.fields.generic

from typing import Any, Optional, Type

from classical.fields.base import ClassField, FieldInspector, FieldSchema
from classical.fields.namedtuple import NamedTupleFieldInspector
from classical.fields.dict import DictFieldInspector
from classical.fields.attrs import AttrsFieldInspector
from classical.fields.dataclass import DataclassFieldInspector

try:
    from classical.fields.schematics import SchematicsFieldInspector
except ImportError:
    SchematicsFieldInspector = None

try:
    from classical.fields.sqlalchemy import SQLAlchemyModelFieldInspector
except ImportError:
    SQLAlchemyModelFieldInspector = None


INSPECTOR_REGISTRY = [
    cls for cls in (
        NamedTupleFieldInspector,
        DictFieldInspector,
        AttrsFieldInspector,
        DataclassFieldInspector,
        SchematicsFieldInspector,
        SQLAlchemyModelFieldInspector,
    ) if cls is not None
]


class GenericFieldInspector(FieldInspector[ClassField]):
    @classmethod
    def _resolve_specific_inspector_cls(cls, insp_cls: type) -> Optional[Type[FieldInspector]]:
        for inspector_cls in INSPECTOR_REGISTRY:
            try:
                inspector_cls._validate_cls(insp_cls)
                return inspector_cls
            except TypeError:
                pass

        return None

    @classmethod
    def _validate_cls(cls, insp_cls: type) -> None:
        inspector_cls = cls._resolve_specific_inspector_cls(insp_cls)
        if inspector_cls is None:
            cls._raise_unsupported_field_class(insp_cls=insp_cls)

    @classmethod
    def _get_class_fields(cls, insp_cls: type) -> FieldSchema[ClassField]:
        inspector_cls = cls._resolve_specific_inspector_cls(insp_cls)
        if inspector_cls is None:
            cls._raise_unsupported_field_class(insp_cls=insp_cls)
        return inspector_cls._get_class_fields(insp_cls=insp_cls)

    @classmethod
    def _get_instance_fields(cls, obj: Any) -> FieldSchema[ClassField]:
        inspector_cls = cls._resolve_specific_inspector_cls(type(obj))
        if inspector_cls is None:
            cls._raise_unsupported_field_class(insp_cls=type(obj))
        return inspector_cls._get_instance_fields(obj=obj)