diff options
Diffstat (limited to 'lib/sqlalchemy/ext/declarative')
| -rw-r--r-- | lib/sqlalchemy/ext/declarative/__init__.py | 60 | ||||
| -rw-r--r-- | lib/sqlalchemy/ext/declarative/api.py | 106 | ||||
| -rw-r--r-- | lib/sqlalchemy/ext/declarative/base.py | 95 | ||||
| -rw-r--r-- | lib/sqlalchemy/ext/declarative/clsregistry.py | 93 |
4 files changed, 277 insertions, 77 deletions
diff --git a/lib/sqlalchemy/ext/declarative/__init__.py b/lib/sqlalchemy/ext/declarative/__init__.py index f8c685da0..0ee4e33fd 100644 --- a/lib/sqlalchemy/ext/declarative/__init__.py +++ b/lib/sqlalchemy/ext/declarative/__init__.py @@ -1,5 +1,5 @@ # ext/declarative/__init__.py -# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file> +# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php @@ -897,11 +897,57 @@ reference a common target class via many-to-one:: __tablename__ = 'target' id = Column(Integer, primary_key=True) +Using Advanced Relationship Arguments (e.g. ``primaryjoin``, etc.) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + :func:`~sqlalchemy.orm.relationship` definitions which require explicit -primaryjoin, order_by etc. expressions should use the string forms -for these arguments, so that they are evaluated as late as possible. -To reference the mixin class in these expressions, use the given ``cls`` -to get its name:: +primaryjoin, order_by etc. expressions should in all but the most +simplistic cases use **late bound** forms +for these arguments, meaning, using either the string form or a lambda. +The reason for this is that the related :class:`.Column` objects which are to +be configured using ``@declared_attr`` are not available to another +``@declared_attr`` attribute; while the methods will work and return new +:class:`.Column` objects, those are not the :class:`.Column` objects that +Declarative will be using as it calls the methods on its own, thus using +*different* :class:`.Column` objects. + +The canonical example is the primaryjoin condition that depends upon +another mixed-in column:: + + class RefTargetMixin(object): + @declared_attr + def target_id(cls): + return Column('target_id', ForeignKey('target.id')) + + @declared_attr + def target(cls): + return relationship(Target, + primaryjoin=Target.id==cls.target_id # this is *incorrect* + ) + +Mapping a class using the above mixin, we will get an error like:: + + sqlalchemy.exc.InvalidRequestError: this ForeignKey's parent column is not + yet associated with a Table. + +This is because the ``target_id`` :class:`.Column` we've called upon in our ``target()`` +method is not the same :class:`.Column` that declarative is actually going to map +to our table. + +The condition above is resolved using a lambda:: + + class RefTargetMixin(object): + @declared_attr + def target_id(cls): + return Column('target_id', ForeignKey('target.id')) + + @declared_attr + def target(cls): + return relationship(Target, + primaryjoin=lambda: Target.id==cls.target_id + ) + +or alternatively, the string form (which ultmately generates a lambda):: class RefTargetMixin(object): @declared_attr @@ -1238,7 +1284,7 @@ Sessions Note that ``declarative`` does nothing special with sessions, and is only intended as an easier way to configure mappers and :class:`~sqlalchemy.schema.Table` objects. A typical application -setup using :class:`~sqlalchemy.orm.scoped_session` might look like:: +setup using :class:`~sqlalchemy.orm.scoping.scoped_session` might look like:: engine = create_engine('postgresql://scott:tiger@localhost/test') Session = scoped_session(sessionmaker(autocommit=False, @@ -1254,7 +1300,7 @@ Mapped instances then make usage of from .api import declarative_base, synonym_for, comparable_using, \ instrument_declarative, ConcreteBase, AbstractConcreteBase, \ DeclarativeMeta, DeferredReflection, has_inherited_table,\ - declared_attr + declared_attr, as_declarative __all__ = ['declarative_base', 'synonym_for', 'has_inherited_table', diff --git a/lib/sqlalchemy/ext/declarative/api.py b/lib/sqlalchemy/ext/declarative/api.py index 2f222f682..2418c6e50 100644 --- a/lib/sqlalchemy/ext/declarative/api.py +++ b/lib/sqlalchemy/ext/declarative/api.py @@ -1,5 +1,5 @@ # ext/declarative/api.py -# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file> +# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php @@ -9,14 +9,17 @@ from ...schema import Table, MetaData from ...orm import synonym as _orm_synonym, mapper,\ comparable_property,\ - interfaces -from ...orm.util import polymorphic_union, _mapper_or_none + interfaces, properties +from ...orm.util import polymorphic_union +from ...orm.base import _mapper_or_none +from ...util import compat from ... import exc import weakref from .base import _as_declarative, \ _declarative_constructor,\ - _MapperConfig, _add_attribute + _DeferredMapperConfig, _add_attribute +from .clsregistry import _class_resolver def instrument_declarative(cls, registry, metadata): @@ -173,16 +176,16 @@ def declarative_base(bind=None, metadata=None, mapper=None, cls=object, of the class. :param bind: An optional - :class:`~sqlalchemy.engine.base.Connectable`, will be assigned - the ``bind`` attribute on the :class:`~sqlalchemy.MetaData` + :class:`~sqlalchemy.engine.Connectable`, will be assigned + the ``bind`` attribute on the :class:`~sqlalchemy.schema.MetaData` instance. :param metadata: - An optional :class:`~sqlalchemy.MetaData` instance. All + An optional :class:`~sqlalchemy.schema.MetaData` instance. All :class:`~sqlalchemy.schema.Table` objects implicitly declared by subclasses of the base will share this MetaData. A MetaData instance will be created if none is provided. The - :class:`~sqlalchemy.MetaData` instance will be available via the + :class:`~sqlalchemy.schema.MetaData` instance will be available via the `metadata` attribute of the generated declarative base class. :param mapper: @@ -218,6 +221,10 @@ def declarative_base(bind=None, metadata=None, mapper=None, cls=object, compatible callable to use as the meta type of the generated declarative base class. + .. seealso:: + + :func:`.as_declarative` + """ lcl_metadata = metadata or MetaData() if bind: @@ -237,6 +244,42 @@ def declarative_base(bind=None, metadata=None, mapper=None, cls=object, return metaclass(name, bases, class_dict) +def as_declarative(**kw): + """ + Class decorator for :func:`.declarative_base`. + + Provides a syntactical shortcut to the ``cls`` argument + sent to :func:`.declarative_base`, allowing the base class + to be converted in-place to a "declarative" base:: + + from sqlalchemy.ext.declarative import as_declarative + + @as_declarative() + class Base(object): + @declared_attr + def __tablename__(cls): + return cls.__name__.lower() + id = Column(Integer, primary_key=True) + + class MyMappedClass(Base): + # ... + + All keyword arguments passed to :func:`.as_declarative` are passed + along to :func:`.declarative_base`. + + .. versionadded:: 0.8.3 + + .. seealso:: + + :func:`.declarative_base` + + """ + def decorate(cls): + kw['cls'] = cls + kw['name'] = cls.__name__ + return declarative_base(**kw) + + return decorate class ConcreteBase(object): """A helper class for 'concrete' declarative mappings. @@ -245,7 +288,7 @@ class ConcreteBase(object): function automatically, against all tables mapped as a subclass to this class. The function is called via the ``__declare_last__()`` function, which is essentially - a hook for the :func:`.MapperEvents.after_configured` event. + a hook for the :meth:`.after_configured` event. :class:`.ConcreteBase` produces a mapped table for the class itself. Compare to :class:`.AbstractConcreteBase`, @@ -300,7 +343,7 @@ class AbstractConcreteBase(ConcreteBase): function automatically, against all tables mapped as a subclass to this class. The function is called via the ``__declare_last__()`` function, which is essentially - a hook for the :func:`.MapperEvents.after_configured` event. + a hook for the :meth:`.after_configured` event. :class:`.AbstractConcreteBase` does not produce a mapped table for the class itself. Compare to :class:`.ConcreteBase`, @@ -380,7 +423,7 @@ class DeferredReflection(object): Above, ``MyClass`` is not yet mapped. After a series of classes have been defined in the above fashion, all tables can be reflected and mappings created using - :meth:`.DeferredReflection.prepare`:: + :meth:`.prepare`:: engine = create_engine("someengine://...") DeferredReflection.prepare(engine) @@ -424,11 +467,30 @@ class DeferredReflection(object): def prepare(cls, engine): """Reflect all :class:`.Table` objects for all current :class:`.DeferredReflection` subclasses""" - to_map = [m for m in _MapperConfig.configs.values() - if issubclass(m.cls, cls)] + + to_map = _DeferredMapperConfig.classes_for_base(cls) for thingy in to_map: cls._sa_decl_prepare(thingy.local_table, engine) thingy.map() + mapper = thingy.cls.__mapper__ + metadata = mapper.class_.metadata + for rel in mapper._props.values(): + if isinstance(rel, properties.RelationshipProperty) and \ + rel.secondary is not None: + if isinstance(rel.secondary, Table): + cls._reflect_table(rel.secondary, engine) + elif isinstance(rel.secondary, _class_resolver): + rel.secondary._resolvers += ( + cls._sa_deferred_table_resolver(engine, metadata), + ) + + @classmethod + def _sa_deferred_table_resolver(cls, engine, metadata): + def _resolve(key): + t1 = Table(key, metadata) + cls._reflect_table(t1, engine) + return t1 + return _resolve @classmethod def _sa_decl_prepare(cls, local_table, engine): @@ -437,10 +499,14 @@ class DeferredReflection(object): # will fill in db-loaded columns # into the existing Table object. if local_table is not None: - Table(local_table.name, - local_table.metadata, - extend_existing=True, - autoload_replace=False, - autoload=True, - autoload_with=engine, - schema=local_table.schema) + cls._reflect_table(local_table, engine) + + @classmethod + def _reflect_table(cls, table, engine): + Table(table.name, + table.metadata, + extend_existing=True, + autoload_replace=False, + autoload=True, + autoload_with=engine, + schema=table.schema) diff --git a/lib/sqlalchemy/ext/declarative/base.py b/lib/sqlalchemy/ext/declarative/base.py index 5a2b88db4..a764f126b 100644 --- a/lib/sqlalchemy/ext/declarative/base.py +++ b/lib/sqlalchemy/ext/declarative/base.py @@ -1,25 +1,27 @@ # ext/declarative/base.py -# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file> +# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php """Internal implementation for declarative.""" from ...schema import Table, Column -from ...orm import mapper, class_mapper +from ...orm import mapper, class_mapper, synonym from ...orm.interfaces import MapperProperty from ...orm.properties import ColumnProperty, CompositeProperty -from ...orm.util import _is_mapped_class +from ...orm.attributes import QueryableAttribute +from ...orm.base import _is_mapped_class from ... import util, exc from ...sql import expression from ... import event from . import clsregistry - +import collections +import weakref def _declared_mapping_info(cls): # deferred mapping - if cls in _MapperConfig.configs: - return _MapperConfig.configs[cls] + if _DeferredMapperConfig.has_cls(cls): + return _DeferredMapperConfig.config_for_cls(cls) # regular mapping elif _is_mapped_class(cls): return class_mapper(cls, configure=False) @@ -148,6 +150,15 @@ def _as_declarative(cls, classname, dict_): if isinstance(value, declarative_props): 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 = synonym(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 " @@ -173,15 +184,19 @@ def _as_declarative(cls, classname, dict_): # extract columns from the class dict declared_columns = set() + 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. @@ -190,6 +205,15 @@ def _as_declarative(cls, classname, dict_): # 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" % + (classname, name, (", ".join(sorted(keys)))) + ) + declared_columns = sorted( declared_columns, key=lambda c: c._creation_order) table = None @@ -281,19 +305,24 @@ def _as_declarative(cls, classname, dict_): inherited_mapped_table is not inherited_table: inherited_mapped_table._refresh_for_new_column(c) - mt = _MapperConfig(mapper_cls, + defer_map = hasattr(cls, '_sa_decl_prepare') + if defer_map: + cfg_cls = _DeferredMapperConfig + else: + cfg_cls = _MapperConfig + mt = cfg_cls(mapper_cls, cls, table, inherits, declared_columns, column_copies, our_stuff, mapper_args_fn) - if not hasattr(cls, '_sa_decl_prepare'): + if not defer_map: mt.map() class _MapperConfig(object): - configs = util.OrderedDict() + mapped_table = None def __init__(self, mapper_cls, @@ -311,7 +340,7 @@ class _MapperConfig(object): self.mapper_args_fn = mapper_args_fn self.declared_columns = declared_columns self.column_copies = column_copies - self.configs[cls] = self + def _prepare_mapper_arguments(self): properties = self.properties @@ -368,7 +397,6 @@ class _MapperConfig(object): return result_mapper_args def map(self): - self.configs.pop(self.cls, None) mapper_args = self._prepare_mapper_arguments() self.cls.__mapper__ = self.mapper_cls( self.cls, @@ -376,6 +404,42 @@ class _MapperConfig(object): **mapper_args ) +class _DeferredMapperConfig(_MapperConfig): + _configs = util.OrderedDict() + + @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 config_for_cls(cls, class_): + return cls._configs[weakref.ref(class_)] + + + @classmethod + def classes_for_base(cls, base_cls): + return [m for m in cls._configs.values() + if issubclass(m.cls, base_cls)] + + def map(self): + self._configs.pop(self._cls, None) + super(_DeferredMapperConfig, self).map() + def _add_attribute(cls, key, value): """add an attribute to an existing declarative class. @@ -384,6 +448,7 @@ def _add_attribute(cls, key, value): 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) @@ -400,6 +465,14 @@ def _add_attribute(cls, key, value): key, clsregistry._deferred_relationship(cls, 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 = synonym(value.key) + cls.__mapper__.add_property( + key, + clsregistry._deferred_relationship(cls, value) + ) else: type.__setattr__(cls, key, value) else: diff --git a/lib/sqlalchemy/ext/declarative/clsregistry.py b/lib/sqlalchemy/ext/declarative/clsregistry.py index a669e37f4..fda1cffb5 100644 --- a/lib/sqlalchemy/ext/declarative/clsregistry.py +++ b/lib/sqlalchemy/ext/declarative/clsregistry.py @@ -1,5 +1,5 @@ # ext/declarative/clsregistry.py -# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file> +# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php @@ -225,47 +225,62 @@ def _determine_container(key, value): return _GetColumns(value) -def _resolver(cls, prop): - def resolve_arg(arg): - import sqlalchemy - from sqlalchemy.orm import foreign, remote - - fallback = sqlalchemy.__dict__.copy() - fallback.update({'foreign': foreign, 'remote': remote}) - - def access_cls(key): - if key in cls._decl_class_registry: - return _determine_container(key, cls._decl_class_registry[key]) - elif key in cls.metadata.tables: - return cls.metadata.tables[key] - elif key in cls.metadata._schemas: - return _GetTable(key, cls.metadata) - elif '_sa_module_registry' in cls._decl_class_registry and \ - key in cls._decl_class_registry['_sa_module_registry']: - registry = cls._decl_class_registry['_sa_module_registry'] - return registry.resolve_attr(key) +class _class_resolver(object): + def __init__(self, cls, prop, fallback, arg): + self.cls = cls + self.prop = prop + self.arg = self._declarative_arg = arg + self.fallback = fallback + self._dict = util.PopulateDict(self._access_cls) + self._resolvers = () + + def _access_cls(self, key): + cls = self.cls + if key in cls._decl_class_registry: + return _determine_container(key, cls._decl_class_registry[key]) + elif key in cls.metadata.tables: + return cls.metadata.tables[key] + elif key in cls.metadata._schemas: + return _GetTable(key, cls.metadata) + elif '_sa_module_registry' in cls._decl_class_registry and \ + key in cls._decl_class_registry['_sa_module_registry']: + registry = cls._decl_class_registry['_sa_module_registry'] + return registry.resolve_attr(key) + elif self._resolvers: + for resolv in self._resolvers: + value = resolv(key) + if value is not None: + return value + + return self.fallback[key] + + def __call__(self): + try: + x = eval(self.arg, globals(), self._dict) + + if isinstance(x, _GetColumns): + return x.cls else: - return fallback[key] + return x + except NameError as n: + raise exc.InvalidRequestError( + "When initializing mapper %s, expression %r failed to " + "locate a name (%r). If this is a class name, consider " + "adding this relationship() to the %r class after " + "both dependent classes have been defined." % + (self.prop.parent, self.arg, n.args[0], self.cls) + ) - d = util.PopulateDict(access_cls) - def return_cls(): - try: - x = eval(arg, globals(), d) +def _resolver(cls, prop): + import sqlalchemy + from sqlalchemy.orm import foreign, remote - if isinstance(x, _GetColumns): - return x.cls - else: - return x - except NameError as n: - raise exc.InvalidRequestError( - "When initializing mapper %s, expression %r failed to " - "locate a name (%r). If this is a class name, consider " - "adding this relationship() to the %r class after " - "both dependent classes have been defined." % - (prop.parent, arg, n.args[0], cls) - ) - return return_cls + fallback = sqlalchemy.__dict__.copy() + fallback.update({'foreign': foreign, 'remote': remote}) + + def resolve_arg(arg): + return _class_resolver(cls, prop, fallback, arg) return resolve_arg @@ -277,7 +292,7 @@ def _deferred_relationship(cls, prop): for attr in ('argument', 'order_by', 'primaryjoin', 'secondaryjoin', 'secondary', '_user_defined_foreign_keys', 'remote_side'): v = getattr(prop, attr) - if isinstance(v, str): + if isinstance(v, util.string_types): setattr(prop, attr, resolve_arg(v)) if prop.backref and isinstance(prop.backref, tuple): |