1156 lines
42 KiB
Python
1156 lines
42 KiB
Python
# ext/declarative/base.py
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# Copyright (C) 2005-2021 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""Internal implementation for declarative."""
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from __future__ import absolute_import
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import collections
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import weakref
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from sqlalchemy.orm import attributes
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from sqlalchemy.orm import instrumentation
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from . import clsregistry
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from . import exc as orm_exc
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from . import mapper as mapperlib
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from .attributes import InstrumentedAttribute
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from .attributes import QueryableAttribute
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from .base import _is_mapped_class
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from .base import InspectionAttr
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from .descriptor_props import CompositeProperty
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from .descriptor_props import SynonymProperty
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from .interfaces import MapperProperty
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from .mapper import Mapper as mapper
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from .properties import ColumnProperty
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from .util import class_mapper
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from .. import event
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from .. import exc
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from .. import util
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from ..sql import expression
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from ..sql.schema import Column
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from ..sql.schema import Table
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from ..util import topological
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def _declared_mapping_info(cls):
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# deferred mapping
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if _DeferredMapperConfig.has_cls(cls):
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return _DeferredMapperConfig.config_for_cls(cls)
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# regular mapping
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elif _is_mapped_class(cls):
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return class_mapper(cls, configure=False)
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else:
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return None
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def _resolve_for_abstract_or_classical(cls):
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if cls is object:
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return None
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if cls.__dict__.get("__abstract__", False):
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for sup in cls.__bases__:
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sup = _resolve_for_abstract_or_classical(sup)
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if sup is not None:
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return sup
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else:
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return None
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else:
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clsmanager = _dive_for_cls_manager(cls)
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if clsmanager:
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return clsmanager.class_
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else:
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return cls
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def _get_immediate_cls_attr(cls, attrname, strict=False):
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"""return an attribute of the class that is either present directly
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on the class, e.g. not on a superclass, or is from a superclass but
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this superclass is a non-mapped mixin, that is, not a descendant of
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the declarative base and is also not classically mapped.
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This is used to detect attributes that indicate something about
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a mapped class independently from any mapped classes that it may
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inherit from.
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"""
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# the rules are different for this name than others,
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# make sure we've moved it out. transitional
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assert attrname != "__abstract__"
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if not issubclass(cls, object):
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return None
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if attrname in cls.__dict__:
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return getattr(cls, attrname)
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for base in cls.__mro__[1:]:
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_is_classicial_inherits = _dive_for_cls_manager(base)
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if attrname in base.__dict__ and (
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base is cls
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or (
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(base in cls.__bases__ if strict else True)
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and not _is_classicial_inherits
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)
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):
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return getattr(base, attrname)
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else:
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return None
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def _dive_for_cls_manager(cls):
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# because the class manager registration is pluggable,
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# we need to do the search for every class in the hierarchy,
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# rather than just a simple "cls._sa_class_manager"
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# python 2 old style class
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if not hasattr(cls, "__mro__"):
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return None
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for base in cls.__mro__:
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manager = attributes.manager_of_class(base)
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if manager:
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return manager
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return None
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def _as_declarative(registry, cls, dict_):
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# declarative scans the class for attributes. no table or mapper
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# args passed separately.
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return _MapperConfig.setup_mapping(registry, cls, dict_, None, {})
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def _mapper(registry, cls, table, mapper_kw):
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_ImperativeMapperConfig(registry, cls, table, mapper_kw)
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return cls.__mapper__
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@util.preload_module("sqlalchemy.orm.decl_api")
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def _is_declarative_props(obj):
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declared_attr = util.preloaded.orm_decl_api.declared_attr
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return isinstance(obj, (declared_attr, util.classproperty))
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def _check_declared_props_nocascade(obj, name, cls):
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if _is_declarative_props(obj):
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if getattr(obj, "_cascading", False):
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util.warn(
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"@declared_attr.cascading is not supported on the %s "
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"attribute on class %s. This attribute invokes for "
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"subclasses in any case." % (name, cls)
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)
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return True
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else:
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return False
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class _MapperConfig(object):
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__slots__ = ("cls", "classname", "properties", "declared_attr_reg")
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@classmethod
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def setup_mapping(cls, registry, cls_, dict_, table, mapper_kw):
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manager = attributes.manager_of_class(cls)
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if manager and manager.class_ is cls_:
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raise exc.InvalidRequestError(
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"Class %r already has been " "instrumented declaratively" % cls
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)
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if cls_.__dict__.get("__abstract__", False):
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return
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defer_map = _get_immediate_cls_attr(
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cls_, "_sa_decl_prepare_nocascade", strict=True
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) or hasattr(cls_, "_sa_decl_prepare")
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if defer_map:
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cfg_cls = _DeferredMapperConfig
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else:
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cfg_cls = _ClassScanMapperConfig
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return cfg_cls(registry, cls_, dict_, table, mapper_kw)
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def __init__(self, registry, cls_):
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self.cls = cls_
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self.classname = cls_.__name__
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self.properties = util.OrderedDict()
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self.declared_attr_reg = {}
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instrumentation.register_class(
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self.cls,
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finalize=False,
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registry=registry,
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declarative_scan=self,
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init_method=registry.constructor,
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)
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def set_cls_attribute(self, attrname, value):
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manager = instrumentation.manager_of_class(self.cls)
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manager.install_member(attrname, value)
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return value
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def _early_mapping(self, mapper_kw):
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self.map(mapper_kw)
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class _ImperativeMapperConfig(_MapperConfig):
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__slots__ = ("dict_", "local_table", "inherits")
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def __init__(
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self,
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registry,
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cls_,
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table,
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mapper_kw,
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):
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super(_ImperativeMapperConfig, self).__init__(registry, cls_)
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self.dict_ = {}
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self.local_table = self.set_cls_attribute("__table__", table)
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with mapperlib._CONFIGURE_MUTEX:
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clsregistry.add_class(
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self.classname, self.cls, registry._class_registry
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)
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self._setup_inheritance(mapper_kw)
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self._early_mapping(mapper_kw)
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def map(self, mapper_kw=util.EMPTY_DICT):
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mapper_cls = mapper
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return self.set_cls_attribute(
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"__mapper__",
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mapper_cls(self.cls, self.local_table, **mapper_kw),
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)
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def _setup_inheritance(self, mapper_kw):
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cls = self.cls
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inherits = mapper_kw.get("inherits", None)
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if inherits is None:
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# since we search for classical mappings now, search for
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# multiple mapped bases as well and raise an error.
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inherits_search = []
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for c in cls.__bases__:
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c = _resolve_for_abstract_or_classical(c)
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if c is None:
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continue
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if _declared_mapping_info(
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c
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) is not None and not _get_immediate_cls_attr(
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c, "_sa_decl_prepare_nocascade", strict=True
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):
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inherits_search.append(c)
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if inherits_search:
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if len(inherits_search) > 1:
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raise exc.InvalidRequestError(
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"Class %s has multiple mapped bases: %r"
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% (cls, inherits_search)
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)
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inherits = inherits_search[0]
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elif isinstance(inherits, mapper):
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inherits = inherits.class_
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self.inherits = inherits
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class _ClassScanMapperConfig(_MapperConfig):
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__slots__ = (
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"dict_",
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"local_table",
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"persist_selectable",
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"declared_columns",
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"column_copies",
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"table_args",
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"tablename",
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"mapper_args",
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"mapper_args_fn",
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"inherits",
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)
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def __init__(
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self,
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registry,
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cls_,
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dict_,
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table,
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mapper_kw,
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):
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super(_ClassScanMapperConfig, self).__init__(registry, cls_)
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self.dict_ = dict(dict_) if dict_ else {}
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self.persist_selectable = None
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self.declared_columns = set()
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self.column_copies = {}
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self._setup_declared_events()
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self._scan_attributes()
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with mapperlib._CONFIGURE_MUTEX:
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clsregistry.add_class(
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self.classname, self.cls, registry._class_registry
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)
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self._extract_mappable_attributes()
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self._extract_declared_columns()
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self._setup_table(table)
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self._setup_inheritance(mapper_kw)
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self._early_mapping(mapper_kw)
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def _setup_declared_events(self):
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if _get_immediate_cls_attr(self.cls, "__declare_last__"):
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@event.listens_for(mapper, "after_configured")
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def after_configured():
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self.cls.__declare_last__()
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if _get_immediate_cls_attr(self.cls, "__declare_first__"):
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@event.listens_for(mapper, "before_configured")
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def before_configured():
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self.cls.__declare_first__()
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def _cls_attr_override_checker(self, cls):
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"""Produce a function that checks if a class has overridden an
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attribute, taking SQLAlchemy-enabled dataclass fields into account.
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"""
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sa_dataclass_metadata_key = _get_immediate_cls_attr(
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cls, "__sa_dataclass_metadata_key__", None
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)
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if sa_dataclass_metadata_key is None:
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def attribute_is_overridden(key, obj):
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return getattr(cls, key) is not obj
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else:
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all_datacls_fields = {
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f.name: f.metadata[sa_dataclass_metadata_key]
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for f in util.dataclass_fields(cls)
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if sa_dataclass_metadata_key in f.metadata
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}
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local_datacls_fields = {
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f.name: f.metadata[sa_dataclass_metadata_key]
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for f in util.local_dataclass_fields(cls)
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if sa_dataclass_metadata_key in f.metadata
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}
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absent = object()
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def attribute_is_overridden(key, obj):
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if _is_declarative_props(obj):
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obj = obj.fget
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# this function likely has some failure modes still if
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# someone is doing a deep mixing of the same attribute
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# name as plain Python attribute vs. dataclass field.
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ret = local_datacls_fields.get(key, absent)
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if _is_declarative_props(ret):
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ret = ret.fget
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if ret is obj:
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return False
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elif ret is not absent:
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return True
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all_field = all_datacls_fields.get(key, absent)
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ret = getattr(cls, key, obj)
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if ret is obj:
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return False
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# for dataclasses, this could be the
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# 'default' of the field. so filter more specifically
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# for an already-mapped InstrumentedAttribute
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if ret is not absent and isinstance(
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ret, InstrumentedAttribute
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):
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return True
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if all_field is obj:
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return False
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elif all_field is not absent:
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return True
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# can't find another attribute
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return False
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return attribute_is_overridden
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def _cls_attr_resolver(self, cls):
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"""produce a function to iterate the "attributes" of a class,
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adjusting for SQLAlchemy fields embedded in dataclass fields.
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"""
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sa_dataclass_metadata_key = _get_immediate_cls_attr(
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cls, "__sa_dataclass_metadata_key__", None
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)
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if sa_dataclass_metadata_key is None:
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def local_attributes_for_class():
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for name, obj in vars(cls).items():
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yield name, obj, False
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else:
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field_names = set()
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def local_attributes_for_class():
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for field in util.local_dataclass_fields(cls):
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if sa_dataclass_metadata_key in field.metadata:
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field_names.add(field.name)
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yield field.name, _as_dc_declaredattr(
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field.metadata, sa_dataclass_metadata_key
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), True
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for name, obj in vars(cls).items():
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if name not in field_names:
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yield name, obj, False
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return local_attributes_for_class
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def _scan_attributes(self):
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cls = self.cls
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dict_ = self.dict_
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column_copies = self.column_copies
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mapper_args_fn = None
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table_args = inherited_table_args = None
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tablename = None
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attribute_is_overridden = self._cls_attr_override_checker(self.cls)
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for base in cls.__mro__:
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class_mapped = (
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base is not cls
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and _declared_mapping_info(base) is not None
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and not _get_immediate_cls_attr(
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base, "_sa_decl_prepare_nocascade", strict=True
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)
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)
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local_attributes_for_class = self._cls_attr_resolver(base)
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if not class_mapped and base is not cls:
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self._produce_column_copies(
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local_attributes_for_class, attribute_is_overridden
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)
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for name, obj, is_dataclass in local_attributes_for_class():
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if name == "__mapper_args__":
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check_decl = _check_declared_props_nocascade(
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obj, name, cls
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)
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if not mapper_args_fn and (not class_mapped or check_decl):
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# don't even invoke __mapper_args__ until
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# after we've determined everything about the
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# mapped table.
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# make a copy of it so a class-level dictionary
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# is not overwritten when we update column-based
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# arguments.
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def mapper_args_fn():
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return dict(cls.__mapper_args__)
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elif name == "__tablename__":
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check_decl = _check_declared_props_nocascade(
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obj, name, cls
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)
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if not tablename and (not class_mapped or check_decl):
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tablename = cls.__tablename__
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elif name == "__table_args__":
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check_decl = _check_declared_props_nocascade(
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obj, name, cls
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)
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if not table_args and (not class_mapped or check_decl):
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table_args = cls.__table_args__
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if not isinstance(
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table_args, (tuple, dict, type(None))
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):
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raise exc.ArgumentError(
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"__table_args__ value must be a tuple, "
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"dict, or None"
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)
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if base is not cls:
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inherited_table_args = True
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elif class_mapped:
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if _is_declarative_props(obj):
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util.warn(
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"Regular (i.e. not __special__) "
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"attribute '%s.%s' uses @declared_attr, "
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"but owning class %s is mapped - "
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"not applying to subclass %s."
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% (base.__name__, name, base, cls)
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)
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continue
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elif base is not cls:
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# we're a mixin, abstract base, or something that is
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# acting like that for now.
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if isinstance(obj, Column):
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# already copied columns to the mapped class.
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continue
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elif isinstance(obj, MapperProperty):
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raise exc.InvalidRequestError(
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"Mapper properties (i.e. deferred,"
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"column_property(), relationship(), etc.) must "
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"be declared as @declared_attr callables "
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"on declarative mixin classes. For dataclass "
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"field() objects, use a lambda:"
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)
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elif _is_declarative_props(obj):
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if obj._cascading:
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if name in dict_:
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# unfortunately, while we can use the user-
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# defined attribute here to allow a clean
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# override, if there's another
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# subclass below then it still tries to use
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# this. not sure if there is enough
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# information here to add this as a feature
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# later on.
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util.warn(
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"Attribute '%s' on class %s cannot be "
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"processed due to "
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"@declared_attr.cascading; "
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"skipping" % (name, cls)
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)
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dict_[name] = column_copies[
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obj
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] = ret = obj.__get__(obj, cls)
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setattr(cls, name, ret)
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else:
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if is_dataclass:
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# access attribute using normal class access
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# first, to see if it's been mapped on a
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# superclass. note if the dataclasses.field()
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# has "default", this value can be anything.
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ret = getattr(cls, name, None)
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|
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# so, if it's anything that's not ORM
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# mapped, assume we should invoke the
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# declared_attr
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if not isinstance(ret, InspectionAttr):
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ret = obj.fget()
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else:
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# access attribute using normal class access.
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# if the declared attr already took place
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# on a superclass that is mapped, then
|
|
# this is no longer a declared_attr, it will
|
|
# be the InstrumentedAttribute
|
|
ret = getattr(cls, name)
|
|
|
|
# correct for proxies created from hybrid_property
|
|
# or similar. note there is no known case that
|
|
# produces nested proxies, so we are only
|
|
# looking one level deep right now.
|
|
if (
|
|
isinstance(ret, InspectionAttr)
|
|
and ret._is_internal_proxy
|
|
and not isinstance(
|
|
ret.original_property, MapperProperty
|
|
)
|
|
):
|
|
ret = ret.descriptor
|
|
|
|
dict_[name] = column_copies[obj] = ret
|
|
if (
|
|
isinstance(ret, (Column, MapperProperty))
|
|
and ret.doc is None
|
|
):
|
|
ret.doc = obj.__doc__
|
|
# here, the attribute is some other kind of property that
|
|
# we assume is not part of the declarative mapping.
|
|
# however, check for some more common mistakes
|
|
else:
|
|
self._warn_for_decl_attributes(base, name, obj)
|
|
elif is_dataclass and (
|
|
name not in dict_ or dict_[name] is not obj
|
|
):
|
|
# here, we are definitely looking at the target class
|
|
# and not a superclass. this is currently a
|
|
# dataclass-only path. if the name is only
|
|
# a dataclass field and isn't in local cls.__dict__,
|
|
# put the object there.
|
|
# assert that the dataclass-enabled resolver agrees
|
|
# with what we are seeing
|
|
|
|
assert not attribute_is_overridden(name, obj)
|
|
|
|
if _is_declarative_props(obj):
|
|
obj = obj.fget()
|
|
|
|
dict_[name] = obj
|
|
|
|
if inherited_table_args and not tablename:
|
|
table_args = None
|
|
|
|
self.table_args = table_args
|
|
self.tablename = tablename
|
|
self.mapper_args_fn = mapper_args_fn
|
|
|
|
def _warn_for_decl_attributes(self, cls, key, c):
|
|
if isinstance(c, expression.ColumnClause):
|
|
util.warn(
|
|
"Attribute '%s' on class %s appears to be a non-schema "
|
|
"'sqlalchemy.sql.column()' "
|
|
"object; this won't be part of the declarative mapping"
|
|
% (key, cls)
|
|
)
|
|
|
|
def _produce_column_copies(
|
|
self, attributes_for_class, attribute_is_overridden
|
|
):
|
|
cls = self.cls
|
|
dict_ = self.dict_
|
|
column_copies = self.column_copies
|
|
# copy mixin columns to the mapped class
|
|
|
|
for name, obj, is_dataclass in attributes_for_class():
|
|
if isinstance(obj, Column):
|
|
if attribute_is_overridden(name, obj):
|
|
# if column has been overridden
|
|
# (like by the InstrumentedAttribute of the
|
|
# superclass), skip
|
|
continue
|
|
elif obj.foreign_keys:
|
|
raise exc.InvalidRequestError(
|
|
"Columns with foreign keys to other columns "
|
|
"must be declared as @declared_attr callables "
|
|
"on declarative mixin classes. For dataclass "
|
|
"field() objects, use a lambda:."
|
|
)
|
|
elif name not in dict_ and not (
|
|
"__table__" in dict_
|
|
and (obj.name or name) in dict_["__table__"].c
|
|
):
|
|
column_copies[obj] = copy_ = obj._copy()
|
|
copy_._creation_order = obj._creation_order
|
|
setattr(cls, name, copy_)
|
|
dict_[name] = copy_
|
|
|
|
def _extract_mappable_attributes(self):
|
|
cls = self.cls
|
|
dict_ = self.dict_
|
|
|
|
our_stuff = self.properties
|
|
|
|
late_mapped = _get_immediate_cls_attr(
|
|
cls, "_sa_decl_prepare_nocascade", strict=True
|
|
)
|
|
|
|
for k in list(dict_):
|
|
|
|
if k in ("__table__", "__tablename__", "__mapper_args__"):
|
|
continue
|
|
|
|
value = dict_[k]
|
|
if _is_declarative_props(value):
|
|
if value._cascading:
|
|
util.warn(
|
|
"Use of @declared_attr.cascading only applies to "
|
|
"Declarative 'mixin' and 'abstract' classes. "
|
|
"Currently, this flag is ignored on mapped class "
|
|
"%s" % self.cls
|
|
)
|
|
|
|
value = getattr(cls, k)
|
|
|
|
elif (
|
|
isinstance(value, QueryableAttribute)
|
|
and value.class_ is not cls
|
|
and value.key != k
|
|
):
|
|
# detect a QueryableAttribute that's already mapped being
|
|
# assigned elsewhere in userland, turn into a synonym()
|
|
value = SynonymProperty(value.key)
|
|
setattr(cls, k, value)
|
|
|
|
if (
|
|
isinstance(value, tuple)
|
|
and len(value) == 1
|
|
and isinstance(value[0], (Column, MapperProperty))
|
|
):
|
|
util.warn(
|
|
"Ignoring declarative-like tuple value of attribute "
|
|
"'%s': possibly a copy-and-paste error with a comma "
|
|
"accidentally placed at the end of the line?" % k
|
|
)
|
|
continue
|
|
elif not isinstance(value, (Column, MapperProperty)):
|
|
# using @declared_attr for some object that
|
|
# isn't Column/MapperProperty; remove from the dict_
|
|
# and place the evaluated value onto the class.
|
|
if not k.startswith("__"):
|
|
dict_.pop(k)
|
|
self._warn_for_decl_attributes(cls, k, value)
|
|
if not late_mapped:
|
|
setattr(cls, k, value)
|
|
continue
|
|
# we expect to see the name 'metadata' in some valid cases;
|
|
# however at this point we see it's assigned to something trying
|
|
# to be mapped, so raise for that.
|
|
elif k == "metadata":
|
|
raise exc.InvalidRequestError(
|
|
"Attribute name 'metadata' is reserved "
|
|
"for the MetaData instance when using a "
|
|
"declarative base class."
|
|
)
|
|
our_stuff[k] = value
|
|
|
|
def _extract_declared_columns(self):
|
|
our_stuff = self.properties
|
|
|
|
# set up attributes in the order they were created
|
|
util.sort_dictionary(
|
|
our_stuff, key=lambda key: our_stuff[key]._creation_order
|
|
)
|
|
|
|
# extract columns from the class dict
|
|
declared_columns = self.declared_columns
|
|
name_to_prop_key = collections.defaultdict(set)
|
|
for key, c in list(our_stuff.items()):
|
|
if isinstance(c, (ColumnProperty, CompositeProperty)):
|
|
for col in c.columns:
|
|
if isinstance(col, Column) and col.table is None:
|
|
_undefer_column_name(key, col)
|
|
if not isinstance(c, CompositeProperty):
|
|
name_to_prop_key[col.name].add(key)
|
|
declared_columns.add(col)
|
|
elif isinstance(c, Column):
|
|
_undefer_column_name(key, c)
|
|
name_to_prop_key[c.name].add(key)
|
|
declared_columns.add(c)
|
|
# if the column is the same name as the key,
|
|
# remove it from the explicit properties dict.
|
|
# the normal rules for assigning column-based properties
|
|
# will take over, including precedence of columns
|
|
# in multi-column ColumnProperties.
|
|
if key == c.key:
|
|
del our_stuff[key]
|
|
|
|
for name, keys in name_to_prop_key.items():
|
|
if len(keys) > 1:
|
|
util.warn(
|
|
"On class %r, Column object %r named "
|
|
"directly multiple times, "
|
|
"only one will be used: %s. "
|
|
"Consider using orm.synonym instead"
|
|
% (self.classname, name, (", ".join(sorted(keys))))
|
|
)
|
|
|
|
def _setup_table(self, table=None):
|
|
cls = self.cls
|
|
tablename = self.tablename
|
|
table_args = self.table_args
|
|
dict_ = self.dict_
|
|
declared_columns = self.declared_columns
|
|
|
|
manager = attributes.manager_of_class(cls)
|
|
|
|
declared_columns = self.declared_columns = sorted(
|
|
declared_columns, key=lambda c: c._creation_order
|
|
)
|
|
|
|
if "__table__" not in dict_ and table is None:
|
|
if hasattr(cls, "__table_cls__"):
|
|
table_cls = util.unbound_method_to_callable(cls.__table_cls__)
|
|
else:
|
|
table_cls = Table
|
|
|
|
if tablename is not None:
|
|
|
|
args, table_kw = (), {}
|
|
if table_args:
|
|
if isinstance(table_args, dict):
|
|
table_kw = table_args
|
|
elif isinstance(table_args, tuple):
|
|
if isinstance(table_args[-1], dict):
|
|
args, table_kw = table_args[0:-1], table_args[-1]
|
|
else:
|
|
args = table_args
|
|
|
|
autoload_with = dict_.get("__autoload_with__")
|
|
if autoload_with:
|
|
table_kw["autoload_with"] = autoload_with
|
|
|
|
autoload = dict_.get("__autoload__")
|
|
if autoload:
|
|
table_kw["autoload"] = True
|
|
|
|
table = self.set_cls_attribute(
|
|
"__table__",
|
|
table_cls(
|
|
tablename,
|
|
self._metadata_for_cls(manager),
|
|
*(tuple(declared_columns) + tuple(args)),
|
|
**table_kw
|
|
),
|
|
)
|
|
else:
|
|
if table is None:
|
|
table = cls.__table__
|
|
if declared_columns:
|
|
for c in declared_columns:
|
|
if not table.c.contains_column(c):
|
|
raise exc.ArgumentError(
|
|
"Can't add additional column %r when "
|
|
"specifying __table__" % c.key
|
|
)
|
|
self.local_table = table
|
|
|
|
def _metadata_for_cls(self, manager):
|
|
if hasattr(self.cls, "metadata"):
|
|
return self.cls.metadata
|
|
else:
|
|
return manager.registry.metadata
|
|
|
|
def _setup_inheritance(self, mapper_kw):
|
|
table = self.local_table
|
|
cls = self.cls
|
|
table_args = self.table_args
|
|
declared_columns = self.declared_columns
|
|
|
|
inherits = mapper_kw.get("inherits", None)
|
|
|
|
if inherits is None:
|
|
# since we search for classical mappings now, search for
|
|
# multiple mapped bases as well and raise an error.
|
|
inherits_search = []
|
|
for c in cls.__bases__:
|
|
c = _resolve_for_abstract_or_classical(c)
|
|
if c is None:
|
|
continue
|
|
if _declared_mapping_info(
|
|
c
|
|
) is not None and not _get_immediate_cls_attr(
|
|
c, "_sa_decl_prepare_nocascade", strict=True
|
|
):
|
|
if c not in inherits_search:
|
|
inherits_search.append(c)
|
|
|
|
if inherits_search:
|
|
if len(inherits_search) > 1:
|
|
raise exc.InvalidRequestError(
|
|
"Class %s has multiple mapped bases: %r"
|
|
% (cls, inherits_search)
|
|
)
|
|
inherits = inherits_search[0]
|
|
elif isinstance(inherits, mapper):
|
|
inherits = inherits.class_
|
|
|
|
self.inherits = inherits
|
|
|
|
if (
|
|
table is None
|
|
and self.inherits is None
|
|
and not _get_immediate_cls_attr(cls, "__no_table__")
|
|
):
|
|
|
|
raise exc.InvalidRequestError(
|
|
"Class %r does not have a __table__ or __tablename__ "
|
|
"specified and does not inherit from an existing "
|
|
"table-mapped class." % cls
|
|
)
|
|
elif self.inherits:
|
|
inherited_mapper = _declared_mapping_info(self.inherits)
|
|
inherited_table = inherited_mapper.local_table
|
|
inherited_persist_selectable = inherited_mapper.persist_selectable
|
|
|
|
if table is None:
|
|
# single table inheritance.
|
|
# ensure no table args
|
|
if table_args:
|
|
raise exc.ArgumentError(
|
|
"Can't place __table_args__ on an inherited class "
|
|
"with no table."
|
|
)
|
|
# add any columns declared here to the inherited table.
|
|
for c in declared_columns:
|
|
if c.name in inherited_table.c:
|
|
if inherited_table.c[c.name] is c:
|
|
continue
|
|
raise exc.ArgumentError(
|
|
"Column '%s' on class %s conflicts with "
|
|
"existing column '%s'"
|
|
% (c, cls, inherited_table.c[c.name])
|
|
)
|
|
if c.primary_key:
|
|
raise exc.ArgumentError(
|
|
"Can't place primary key columns on an inherited "
|
|
"class with no table."
|
|
)
|
|
inherited_table.append_column(c)
|
|
if (
|
|
inherited_persist_selectable is not None
|
|
and inherited_persist_selectable is not inherited_table
|
|
):
|
|
inherited_persist_selectable._refresh_for_new_column(c)
|
|
|
|
def _prepare_mapper_arguments(self, mapper_kw):
|
|
properties = self.properties
|
|
|
|
if self.mapper_args_fn:
|
|
mapper_args = self.mapper_args_fn()
|
|
else:
|
|
mapper_args = {}
|
|
|
|
if mapper_kw:
|
|
mapper_args.update(mapper_kw)
|
|
|
|
if "properties" in mapper_args:
|
|
properties = dict(properties)
|
|
properties.update(mapper_args["properties"])
|
|
|
|
# make sure that column copies are used rather
|
|
# than the original columns from any mixins
|
|
for k in ("version_id_col", "polymorphic_on"):
|
|
if k in mapper_args:
|
|
v = mapper_args[k]
|
|
mapper_args[k] = self.column_copies.get(v, v)
|
|
|
|
if "inherits" in mapper_args:
|
|
inherits_arg = mapper_args["inherits"]
|
|
if isinstance(inherits_arg, mapper):
|
|
inherits_arg = inherits_arg.class_
|
|
|
|
if inherits_arg is not self.inherits:
|
|
raise exc.InvalidRequestError(
|
|
"mapper inherits argument given for non-inheriting "
|
|
"class %s" % (mapper_args["inherits"])
|
|
)
|
|
|
|
if self.inherits:
|
|
mapper_args["inherits"] = self.inherits
|
|
|
|
if self.inherits and not mapper_args.get("concrete", False):
|
|
# single or joined inheritance
|
|
# exclude any cols on the inherited table which are
|
|
# not mapped on the parent class, to avoid
|
|
# mapping columns specific to sibling/nephew classes
|
|
inherited_mapper = _declared_mapping_info(self.inherits)
|
|
inherited_table = inherited_mapper.local_table
|
|
|
|
if "exclude_properties" not in mapper_args:
|
|
mapper_args["exclude_properties"] = exclude_properties = set(
|
|
[
|
|
c.key
|
|
for c in inherited_table.c
|
|
if c not in inherited_mapper._columntoproperty
|
|
]
|
|
).union(inherited_mapper.exclude_properties or ())
|
|
exclude_properties.difference_update(
|
|
[c.key for c in self.declared_columns]
|
|
)
|
|
|
|
# look through columns in the current mapper that
|
|
# are keyed to a propname different than the colname
|
|
# (if names were the same, we'd have popped it out above,
|
|
# in which case the mapper makes this combination).
|
|
# See if the superclass has a similar column property.
|
|
# If so, join them together.
|
|
for k, col in list(properties.items()):
|
|
if not isinstance(col, expression.ColumnElement):
|
|
continue
|
|
if k in inherited_mapper._props:
|
|
p = inherited_mapper._props[k]
|
|
if isinstance(p, ColumnProperty):
|
|
# note here we place the subclass column
|
|
# first. See [ticket:1892] for background.
|
|
properties[k] = [col] + p.columns
|
|
result_mapper_args = mapper_args.copy()
|
|
result_mapper_args["properties"] = properties
|
|
self.mapper_args = result_mapper_args
|
|
|
|
def map(self, mapper_kw=util.EMPTY_DICT):
|
|
self._prepare_mapper_arguments(mapper_kw)
|
|
if hasattr(self.cls, "__mapper_cls__"):
|
|
mapper_cls = util.unbound_method_to_callable(
|
|
self.cls.__mapper_cls__
|
|
)
|
|
else:
|
|
mapper_cls = mapper
|
|
|
|
return self.set_cls_attribute(
|
|
"__mapper__",
|
|
mapper_cls(self.cls, self.local_table, **self.mapper_args),
|
|
)
|
|
|
|
|
|
@util.preload_module("sqlalchemy.orm.decl_api")
|
|
def _as_dc_declaredattr(field_metadata, sa_dataclass_metadata_key):
|
|
# wrap lambdas inside dataclass fields inside an ad-hoc declared_attr.
|
|
# we can't write it because field.metadata is immutable :( so we have
|
|
# to go through extra trouble to compare these
|
|
decl_api = util.preloaded.orm_decl_api
|
|
obj = field_metadata[sa_dataclass_metadata_key]
|
|
if callable(obj) and not isinstance(obj, decl_api.declared_attr):
|
|
return decl_api.declared_attr(obj)
|
|
else:
|
|
return obj
|
|
|
|
|
|
class _DeferredMapperConfig(_ClassScanMapperConfig):
|
|
_configs = util.OrderedDict()
|
|
|
|
def _early_mapping(self, mapper_kw):
|
|
pass
|
|
|
|
@property
|
|
def cls(self):
|
|
return self._cls()
|
|
|
|
@cls.setter
|
|
def cls(self, class_):
|
|
self._cls = weakref.ref(class_, self._remove_config_cls)
|
|
self._configs[self._cls] = self
|
|
|
|
@classmethod
|
|
def _remove_config_cls(cls, ref):
|
|
cls._configs.pop(ref, None)
|
|
|
|
@classmethod
|
|
def has_cls(cls, class_):
|
|
# 2.6 fails on weakref if class_ is an old style class
|
|
return isinstance(class_, type) and weakref.ref(class_) in cls._configs
|
|
|
|
@classmethod
|
|
def raise_unmapped_for_cls(cls, class_):
|
|
if hasattr(class_, "_sa_raise_deferred_config"):
|
|
class_._sa_raise_deferred_config()
|
|
|
|
raise orm_exc.UnmappedClassError(
|
|
class_,
|
|
msg="Class %s has a deferred mapping on it. It is not yet "
|
|
"usable as a mapped class." % orm_exc._safe_cls_name(class_),
|
|
)
|
|
|
|
@classmethod
|
|
def config_for_cls(cls, class_):
|
|
return cls._configs[weakref.ref(class_)]
|
|
|
|
@classmethod
|
|
def classes_for_base(cls, base_cls, sort=True):
|
|
classes_for_base = [
|
|
m
|
|
for m, cls_ in [(m, m.cls) for m in cls._configs.values()]
|
|
if cls_ is not None and issubclass(cls_, base_cls)
|
|
]
|
|
|
|
if not sort:
|
|
return classes_for_base
|
|
|
|
all_m_by_cls = dict((m.cls, m) for m in classes_for_base)
|
|
|
|
tuples = []
|
|
for m_cls in all_m_by_cls:
|
|
tuples.extend(
|
|
(all_m_by_cls[base_cls], all_m_by_cls[m_cls])
|
|
for base_cls in m_cls.__bases__
|
|
if base_cls in all_m_by_cls
|
|
)
|
|
return list(topological.sort(tuples, classes_for_base))
|
|
|
|
def map(self, mapper_kw=util.EMPTY_DICT):
|
|
self._configs.pop(self._cls, None)
|
|
return super(_DeferredMapperConfig, self).map(mapper_kw)
|
|
|
|
|
|
def _add_attribute(cls, key, value):
|
|
"""add an attribute to an existing declarative class.
|
|
|
|
This runs through the logic to determine MapperProperty,
|
|
adds it to the Mapper, adds a column to the mapped Table, etc.
|
|
|
|
"""
|
|
|
|
if "__mapper__" in cls.__dict__:
|
|
if isinstance(value, Column):
|
|
_undefer_column_name(key, value)
|
|
cls.__table__.append_column(value, replace_existing=True)
|
|
cls.__mapper__.add_property(key, value)
|
|
elif isinstance(value, ColumnProperty):
|
|
for col in value.columns:
|
|
if isinstance(col, Column) and col.table is None:
|
|
_undefer_column_name(key, col)
|
|
cls.__table__.append_column(col, replace_existing=True)
|
|
cls.__mapper__.add_property(key, value)
|
|
elif isinstance(value, MapperProperty):
|
|
cls.__mapper__.add_property(key, value)
|
|
elif isinstance(value, QueryableAttribute) and value.key != key:
|
|
# detect a QueryableAttribute that's already mapped being
|
|
# assigned elsewhere in userland, turn into a synonym()
|
|
value = SynonymProperty(value.key)
|
|
cls.__mapper__.add_property(key, value)
|
|
else:
|
|
type.__setattr__(cls, key, value)
|
|
cls.__mapper__._expire_memoizations()
|
|
else:
|
|
type.__setattr__(cls, key, value)
|
|
|
|
|
|
def _del_attribute(cls, key):
|
|
|
|
if (
|
|
"__mapper__" in cls.__dict__
|
|
and key in cls.__dict__
|
|
and not cls.__mapper__._dispose_called
|
|
):
|
|
value = cls.__dict__[key]
|
|
if isinstance(
|
|
value, (Column, ColumnProperty, MapperProperty, QueryableAttribute)
|
|
):
|
|
raise NotImplementedError(
|
|
"Can't un-map individual mapped attributes on a mapped class."
|
|
)
|
|
else:
|
|
type.__delattr__(cls, key)
|
|
cls.__mapper__._expire_memoizations()
|
|
else:
|
|
type.__delattr__(cls, key)
|
|
|
|
|
|
def _declarative_constructor(self, **kwargs):
|
|
"""A simple constructor that allows initialization from kwargs.
|
|
|
|
Sets attributes on the constructed instance using the names and
|
|
values in ``kwargs``.
|
|
|
|
Only keys that are present as
|
|
attributes of the instance's class are allowed. These could be,
|
|
for example, any mapped columns or relationships.
|
|
"""
|
|
cls_ = type(self)
|
|
for k in kwargs:
|
|
if not hasattr(cls_, k):
|
|
raise TypeError(
|
|
"%r is an invalid keyword argument for %s" % (k, cls_.__name__)
|
|
)
|
|
setattr(self, k, kwargs[k])
|
|
|
|
|
|
_declarative_constructor.__name__ = "__init__"
|
|
|
|
|
|
def _undefer_column_name(key, column):
|
|
if column.key is None:
|
|
column.key = key
|
|
if column.name is None:
|
|
column.name = key
|