diff options
Diffstat (limited to 'lib/sqlalchemy/orm/interfaces.py')
| -rw-r--r-- | lib/sqlalchemy/orm/interfaces.py | 97 |
1 files changed, 96 insertions, 1 deletions
diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py index b5569ce06..e0034061d 100644 --- a/lib/sqlalchemy/orm/interfaces.py +++ b/lib/sqlalchemy/orm/interfaces.py @@ -19,6 +19,7 @@ are exposed when inspecting mappings. from __future__ import annotations import collections +import dataclasses import typing from typing import Any from typing import Callable @@ -27,6 +28,8 @@ from typing import ClassVar from typing import Dict from typing import Iterator from typing import List +from typing import NamedTuple +from typing import NoReturn from typing import Optional from typing import Sequence from typing import Set @@ -51,11 +54,13 @@ from .base import ONETOMANY as ONETOMANY # noqa: F401 from .base import RelationshipDirection as RelationshipDirection # noqa: F401 from .base import SQLORMOperations from .. import ColumnElement +from .. import exc as sa_exc from .. import inspection from .. import util from ..sql import operators from ..sql import roles from ..sql import visitors +from ..sql.base import _NoArg from ..sql.base import ExecutableOption from ..sql.cache_key import HasCacheKey from ..sql.schema import Column @@ -141,6 +146,7 @@ class _IntrospectsAnnotations: cls: Type[Any], key: str, annotation: Optional[_AnnotationScanType], + extracted_mapped_annotation: Optional[_AnnotationScanType], is_dataclass_field: bool, ) -> None: """Perform class-specific initializaton at early declarative scanning @@ -150,6 +156,70 @@ class _IntrospectsAnnotations: """ + def _raise_for_required(self, key: str, cls: Type[Any]) -> NoReturn: + raise sa_exc.ArgumentError( + f"Python typing annotation is required for attribute " + f'"{cls.__name__}.{key}" when primary argument(s) for ' + f'"{self.__class__.__name__}" construct are None or not present' + ) + + +class _AttributeOptions(NamedTuple): + """define Python-local attribute behavior options common to all + :class:`.MapperProperty` objects. + + Currently this includes dataclass-generation arguments. + + .. versionadded:: 2.0 + + """ + + dataclasses_init: Union[_NoArg, bool] + dataclasses_repr: Union[_NoArg, bool] + dataclasses_default: Union[_NoArg, Any] + dataclasses_default_factory: Union[_NoArg, Callable[[], Any]] + + def _as_dataclass_field(self) -> Any: + """Return a ``dataclasses.Field`` object given these arguments.""" + + kw: Dict[str, Any] = {} + if self.dataclasses_default_factory is not _NoArg.NO_ARG: + kw["default_factory"] = self.dataclasses_default_factory + if self.dataclasses_default is not _NoArg.NO_ARG: + kw["default"] = self.dataclasses_default + if self.dataclasses_init is not _NoArg.NO_ARG: + kw["init"] = self.dataclasses_init + if self.dataclasses_repr is not _NoArg.NO_ARG: + kw["repr"] = self.dataclasses_repr + + return dataclasses.field(**kw) + + @classmethod + def _get_arguments_for_make_dataclass( + cls, key: str, annotation: Type[Any], elem: _T + ) -> Union[ + Tuple[str, Type[Any]], Tuple[str, Type[Any], dataclasses.Field[Any]] + ]: + """given attribute key, annotation, and value from a class, return + the argument tuple we would pass to dataclasses.make_dataclass() + for this attribute. + + """ + if isinstance(elem, (MapperProperty, _MapsColumns)): + dc_field = elem._attribute_options._as_dataclass_field() + + return (key, annotation, dc_field) + elif elem is not _NoArg.NO_ARG: + # why is typing not erroring on this? + return (key, annotation, elem) + else: + return (key, annotation) + + +_DEFAULT_ATTRIBUTE_OPTIONS = _AttributeOptions( + _NoArg.NO_ARG, _NoArg.NO_ARG, _NoArg.NO_ARG, _NoArg.NO_ARG +) + class _MapsColumns(_MappedAttribute[_T]): """interface for declarative-capable construct that delivers one or more @@ -158,6 +228,9 @@ class _MapsColumns(_MappedAttribute[_T]): __slots__ = () + _attribute_options: _AttributeOptions + _has_dataclass_arguments: bool + @property def mapper_property_to_assign(self) -> Optional[MapperProperty[_T]]: """return a MapperProperty to be assigned to the declarative mapping""" @@ -199,6 +272,8 @@ class MapperProperty( __slots__ = ( "_configure_started", "_configure_finished", + "_attribute_options", + "_has_dataclass_arguments", "parent", "key", "info", @@ -241,6 +316,15 @@ class MapperProperty( doc: Optional[str] """optional documentation string""" + _attribute_options: _AttributeOptions + """behavioral options for ORM-enabled Python attributes + + .. versionadded:: 2.0 + + """ + + _has_dataclass_arguments: bool + def _memoized_attr_info(self) -> _InfoType: """Info dictionary associated with the object, allowing user-defined data to be associated with this :class:`.InspectionAttr`. @@ -349,9 +433,20 @@ class MapperProperty( """ - def __init__(self) -> None: + def __init__( + self, attribute_options: Optional[_AttributeOptions] = None + ) -> None: self._configure_started = False self._configure_finished = False + if ( + attribute_options + and attribute_options != _DEFAULT_ATTRIBUTE_OPTIONS + ): + self._has_dataclass_arguments = True + self._attribute_options = attribute_options + else: + self._has_dataclass_arguments = False + self._attribute_options = _DEFAULT_ATTRIBUTE_OPTIONS def init(self) -> None: """Called after all mappers are created to assemble |