from __future__ import annotations
from dataclasses import MISSING, fields, replace
from typing import TYPE_CHECKING, Generic, TypeVar
from litestar.dto.base_dto import AbstractDTO
from litestar.dto.data_structures import DTOFieldDefinition
from litestar.dto.field import DTOField, extract_dto_field
from litestar.params import DependencyKwarg, KwargDefinition
from litestar.types.empty import Empty
if TYPE_CHECKING:
from typing import Collection, Generator
from litestar.types.protocols import DataclassProtocol
from litestar.typing import FieldDefinition
__all__ = ("DataclassDTO", "T")
T = TypeVar("T", bound="DataclassProtocol | Collection[DataclassProtocol]")
AnyDataclass = TypeVar("AnyDataclass", bound="DataclassProtocol")
[docs]
class DataclassDTO(AbstractDTO[T], Generic[T]):
"""Support for domain modelling with dataclasses."""
[docs]
@classmethod
def generate_field_definitions(
cls, model_type: type[DataclassProtocol]
) -> Generator[DTOFieldDefinition, None, None]:
dc_fields = {f.name: f for f in fields(model_type)}
properties = cls.get_property_fields(model_type)
for key, field_definition in cls.get_model_type_hints(model_type).items():
if not (dc_field := dc_fields.get(key)):
continue
default = dc_field.default if dc_field.default is not MISSING else Empty
default_factory = dc_field.default_factory if dc_field.default_factory is not MISSING else None
field_definition = replace(
DTOFieldDefinition.from_field_definition(
field_definition=field_definition,
default_factory=default_factory,
dto_field=extract_dto_field(field_definition, dc_field.metadata),
model_name=model_type.__name__,
),
name=key,
default=default,
)
yield (
replace(field_definition, default=Empty, kwarg_definition=default)
if isinstance(default, (KwargDefinition, DependencyKwarg))
else field_definition
)
for key, property_field in properties.items():
if key.startswith("_"):
continue
yield DTOFieldDefinition.from_field_definition(
property_field,
model_name=model_type.__name__,
default_factory=None,
dto_field=DTOField(mark="read-only"),
)
[docs]
@classmethod
def detect_nested_field(cls, field_definition: FieldDefinition) -> bool:
return hasattr(field_definition.annotation, "__dataclass_fields__")
