diff options
Diffstat (limited to 'lib/sqlalchemy/ext/declarative/base.py')
| -rw-r--r-- | lib/sqlalchemy/ext/declarative/base.py | 697 |
1 files changed, 398 insertions, 299 deletions
diff --git a/lib/sqlalchemy/ext/declarative/base.py b/lib/sqlalchemy/ext/declarative/base.py index 94baeeb51..291608b6c 100644 --- a/lib/sqlalchemy/ext/declarative/base.py +++ b/lib/sqlalchemy/ext/declarative/base.py @@ -19,6 +19,9 @@ from ... import event from . import clsregistry import collections import weakref +from sqlalchemy.orm import instrumentation + +declared_attr = declarative_props = None def _declared_mapping_info(cls): @@ -32,322 +35,407 @@ def _declared_mapping_info(cls): return None +def _get_immediate_cls_attr(cls, attrname): + """return an attribute of the class that is either present directly + on the class, e.g. not on a superclass, or is from a superclass but + this superclass is a mixin, that is, not a descendant of + the declarative base. + + This is used to detect attributes that indicate something about + a mapped class independently from any mapped classes that it may + inherit from. + + """ + for base in cls.__mro__: + _is_declarative_inherits = hasattr(base, '_decl_class_registry') + if attrname in base.__dict__: + value = getattr(base, attrname) + if (base is cls or + (base in cls.__bases__ and not _is_declarative_inherits)): + return value + else: + return None + + def _as_declarative(cls, classname, dict_): - from .api import declared_attr + global declared_attr, declarative_props + if declared_attr is None: + from .api import declared_attr + declarative_props = (declared_attr, util.classproperty) - # dict_ will be a dictproxy, which we can't write to, and we need to! - dict_ = dict(dict_) + if _get_immediate_cls_attr(cls, '__abstract__'): + return - column_copies = {} - potential_columns = {} + _MapperConfig.setup_mapping(cls, classname, dict_) - mapper_args_fn = None - table_args = inherited_table_args = None - tablename = None - declarative_props = (declared_attr, util.classproperty) +class _MapperConfig(object): - for base in cls.__mro__: - _is_declarative_inherits = hasattr(base, '_decl_class_registry') + @classmethod + def setup_mapping(cls, cls_, classname, dict_): + defer_map = _get_immediate_cls_attr( + cls_, '_sa_decl_prepare_nocascade') or \ + hasattr(cls_, '_sa_decl_prepare') - if '__declare_last__' in base.__dict__: - @event.listens_for(mapper, "after_configured") - def go(): - cls.__declare_last__() - if '__declare_first__' in base.__dict__: - @event.listens_for(mapper, "before_configured") - def go(): - cls.__declare_first__() - if '__abstract__' in base.__dict__ and base.__abstract__: - if (base is cls or - (base in cls.__bases__ and not _is_declarative_inherits)): - return + if defer_map: + cfg_cls = _DeferredMapperConfig + else: + cfg_cls = _MapperConfig + cfg_cls(cls_, classname, dict_) - class_mapped = _declared_mapping_info(base) is not None + def __init__(self, cls_, classname, dict_): - for name, obj in vars(base).items(): - if name == '__mapper_args__': - if not mapper_args_fn and ( - not class_mapped or - isinstance(obj, declarative_props) - ): - # don't even invoke __mapper_args__ until - # after we've determined everything about the - # mapped table. - # make a copy of it so a class-level dictionary - # is not overwritten when we update column-based - # arguments. - mapper_args_fn = lambda: dict(cls.__mapper_args__) - elif name == '__tablename__': - if not tablename and ( - not class_mapped or - isinstance(obj, declarative_props) - ): - tablename = cls.__tablename__ - elif name == '__table_args__': - if not table_args and ( - not class_mapped or - isinstance(obj, declarative_props) - ): - table_args = cls.__table_args__ - if not isinstance(table_args, (tuple, dict, type(None))): - raise exc.ArgumentError( - "__table_args__ value must be a tuple, " - "dict, or None") - if base is not cls: - inherited_table_args = True - elif class_mapped: - if isinstance(obj, declarative_props): - util.warn("Regular (i.e. not __special__) " - "attribute '%s.%s' uses @declared_attr, " - "but owning class %s is mapped - " - "not applying to subclass %s." - % (base.__name__, name, base, cls)) - continue - elif base is not cls: - # we're a mixin. - if isinstance(obj, Column): - if getattr(cls, name) is not obj: - # if column has been overridden - # (like by the InstrumentedAttribute of the - # superclass), skip + self.cls = cls_ + + # dict_ will be a dictproxy, which we can't write to, and we need to! + self.dict_ = dict(dict_) + self.classname = classname + self.mapped_table = None + self.properties = util.OrderedDict() + self.declared_columns = set() + self.column_copies = {} + self._setup_declared_events() + + # register up front, so that @declared_attr can memoize + # function evaluations in .info + manager = instrumentation.register_class(self.cls) + manager.info['declared_attr_reg'] = {} + + self._scan_attributes() + + clsregistry.add_class(self.classname, self.cls) + + self._extract_mappable_attributes() + + self._extract_declared_columns() + + self._setup_table() + + self._setup_inheritance() + + self._early_mapping() + + def _early_mapping(self): + self.map() + + def _setup_declared_events(self): + if _get_immediate_cls_attr(self.cls, '__declare_last__'): + @event.listens_for(mapper, "after_configured") + def after_configured(): + self.cls.__declare_last__() + + if _get_immediate_cls_attr(self.cls, '__declare_first__'): + @event.listens_for(mapper, "before_configured") + def before_configured(): + self.cls.__declare_first__() + + def _scan_attributes(self): + cls = self.cls + dict_ = self.dict_ + column_copies = self.column_copies + mapper_args_fn = None + table_args = inherited_table_args = None + tablename = None + + for base in cls.__mro__: + class_mapped = base is not cls and \ + _declared_mapping_info(base) is not None and \ + not _get_immediate_cls_attr(base, '_sa_decl_prepare_nocascade') + + if not class_mapped and base is not cls: + self._produce_column_copies(base) + + for name, obj in vars(base).items(): + if name == '__mapper_args__': + if not mapper_args_fn and ( + not class_mapped or + isinstance(obj, declarative_props) + ): + # don't even invoke __mapper_args__ until + # after we've determined everything about the + # mapped table. + # make a copy of it so a class-level dictionary + # is not overwritten when we update column-based + # arguments. + mapper_args_fn = lambda: dict(cls.__mapper_args__) + elif name == '__tablename__': + if not tablename and ( + not class_mapped or + isinstance(obj, declarative_props) + ): + tablename = cls.__tablename__ + elif name == '__table_args__': + if not table_args and ( + not class_mapped or + isinstance(obj, declarative_props) + ): + table_args = cls.__table_args__ + if not isinstance( + table_args, (tuple, dict, type(None))): + raise exc.ArgumentError( + "__table_args__ value must be a tuple, " + "dict, or None") + if base is not cls: + inherited_table_args = True + elif class_mapped: + if isinstance(obj, declarative_props): + util.warn("Regular (i.e. not __special__) " + "attribute '%s.%s' uses @declared_attr, " + "but owning class %s is mapped - " + "not applying to subclass %s." + % (base.__name__, name, base, cls)) + continue + elif base is not cls: + # we're a mixin, abstract base, or something that is + # acting like that for now. + if isinstance(obj, Column): + # already copied columns to the mapped class. continue - if obj.foreign_keys: + elif isinstance(obj, MapperProperty): raise exc.InvalidRequestError( - "Columns with foreign keys to other columns " - "must be declared as @declared_attr callables " - "on declarative mixin classes. ") - if name not in dict_ and not ( - '__table__' in dict_ and - (obj.name or name) in dict_['__table__'].c - ) and name not in potential_columns: - potential_columns[name] = \ - column_copies[obj] = \ - obj.copy() - column_copies[obj]._creation_order = \ - obj._creation_order - elif isinstance(obj, MapperProperty): + "Mapper properties (i.e. deferred," + "column_property(), relationship(), etc.) must " + "be declared as @declared_attr callables " + "on declarative mixin classes.") + elif isinstance(obj, declarative_props): + oldclassprop = isinstance(obj, util.classproperty) + if not oldclassprop and obj._cascading: + dict_[name] = column_copies[obj] = \ + ret = obj.__get__(obj, cls) + else: + if oldclassprop: + util.warn_deprecated( + "Use of sqlalchemy.util.classproperty on " + "declarative classes is deprecated.") + dict_[name] = column_copies[obj] = \ + ret = getattr(cls, name) + if isinstance(ret, (Column, MapperProperty)) and \ + ret.doc is None: + ret.doc = obj.__doc__ + + 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 _produce_column_copies(self, base): + cls = self.cls + dict_ = self.dict_ + column_copies = self.column_copies + # copy mixin columns to the mapped class + for name, obj in vars(base).items(): + if isinstance(obj, Column): + if getattr(cls, name) is not obj: + # if column has been overridden + # (like by the InstrumentedAttribute of the + # superclass), skip + continue + elif obj.foreign_keys: raise exc.InvalidRequestError( - "Mapper properties (i.e. deferred," - "column_property(), relationship(), etc.) must " - "be declared as @declared_attr callables " - "on declarative mixin classes.") - elif isinstance(obj, declarative_props): - dict_[name] = ret = \ - column_copies[obj] = getattr(cls, name) - if isinstance(ret, (Column, MapperProperty)) and \ - ret.doc is None: - ret.doc = obj.__doc__ - - # apply inherited columns as we should - for k, v in potential_columns.items(): - dict_[k] = v - - if inherited_table_args and not tablename: - table_args = None - - clsregistry.add_class(classname, cls) - our_stuff = util.OrderedDict() - - for k in list(dict_): - - # TODO: improve this ? all dunders ? - if k in ('__table__', '__tablename__', '__mapper_args__'): - continue - - value = dict_[k] - 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 " - "%s: possibly a copy-and-paste error with a comma " - "left at the end of the line?" % k) - continue - if not isinstance(value, (Column, MapperProperty)): - if not k.startswith('__'): - dict_.pop(k) - setattr(cls, k, value) - continue - if k == 'metadata': - raise exc.InvalidRequestError( - "Attribute name 'metadata' is reserved " - "for the MetaData instance when using a " - "declarative base class." - ) - prop = clsregistry._deferred_relationship(cls, value) - our_stuff[k] = prop - - # set up attributes in the order they were created - our_stuff.sort(key=lambda key: our_stuff[key]._creation_order) - - # 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. - # 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" % - (classname, name, (", ".join(sorted(keys)))) - ) + "Columns with foreign keys to other columns " + "must be declared as @declared_attr callables " + "on declarative mixin classes. ") + 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_ - declared_columns = sorted( - declared_columns, key=lambda c: c._creation_order) - table = None + def _extract_mappable_attributes(self): + cls = self.cls + dict_ = self.dict_ - if hasattr(cls, '__table_cls__'): - table_cls = util.unbound_method_to_callable(cls.__table_cls__) - else: - table_cls = Table - - if '__table__' not in dict_: - 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 = dict_.get('__autoload__') - if autoload: - table_kw['autoload'] = True - - cls.__table__ = table = table_cls( - tablename, cls.metadata, - *(tuple(declared_columns) + tuple(args)), - **table_kw) - else: - 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 - ) + our_stuff = self.properties - if hasattr(cls, '__mapper_cls__'): - mapper_cls = util.unbound_method_to_callable(cls.__mapper_cls__) - else: - mapper_cls = mapper + for k in list(dict_): - for c in cls.__bases__: - if _declared_mapping_info(c) is not None: - inherits = c - break - else: - inherits = None + if k in ('__table__', '__tablename__', '__mapper_args__'): + continue - if table is None and inherits is None: - 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 inherits: - inherited_mapper = _declared_mapping_info(inherits) - inherited_table = inherited_mapper.local_table - inherited_mapped_table = inherited_mapper.mapped_table - - 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." + value = dict_[k] + 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 " + "%s: possibly a copy-and-paste error with a comma " + "left 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 evaulated value onto the class. + if not k.startswith('__'): + dict_.pop(k) + 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." + ) + prop = clsregistry._deferred_relationship(cls, value) + our_stuff[k] = prop + + def _extract_declared_columns(self): + our_stuff = self.properties + + # set up attributes in the order they were created + our_stuff.sort(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" % + (self.classname, name, (", ".join(sorted(keys)))) ) - # add any columns declared here to the inherited table. - for c in declared_columns: - if c.primary_key: - raise exc.ArgumentError( - "Can't place primary key columns on an inherited " - "class with no table." - ) - 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]) - ) - inherited_table.append_column(c) - if inherited_mapped_table is not None and \ - inherited_mapped_table is not inherited_table: - inherited_mapped_table._refresh_for_new_column(c) - - 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 defer_map: - mt.map() + def _setup_table(self): + cls = self.cls + tablename = self.tablename + table_args = self.table_args + dict_ = self.dict_ + declared_columns = self.declared_columns -class _MapperConfig(object): + declared_columns = self.declared_columns = sorted( + declared_columns, key=lambda c: c._creation_order) + table = None - mapped_table = None - - def __init__(self, mapper_cls, - cls, - table, - inherits, - declared_columns, - column_copies, - properties, mapper_args_fn): - self.mapper_cls = mapper_cls - self.cls = cls + if hasattr(cls, '__table_cls__'): + table_cls = util.unbound_method_to_callable(cls.__table_cls__) + else: + table_cls = Table + + if '__table__' not in dict_: + 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 = dict_.get('__autoload__') + if autoload: + table_kw['autoload'] = True + + cls.__table__ = table = table_cls( + tablename, cls.metadata, + *(tuple(declared_columns) + tuple(args)), + **table_kw) + else: + 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 - self.inherits = inherits - self.properties = properties - self.mapper_args_fn = mapper_args_fn - self.declared_columns = declared_columns - self.column_copies = column_copies + + def _setup_inheritance(self): + table = self.local_table + cls = self.cls + table_args = self.table_args + declared_columns = self.declared_columns + for c in cls.__bases__: + if _declared_mapping_info(c) is not None and \ + not _get_immediate_cls_attr( + c, '_sa_decl_prepare_nocascade'): + self.inherits = c + break + else: + self.inherits = None + + 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_mapped_table = inherited_mapper.mapped_table + + 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.primary_key: + raise exc.ArgumentError( + "Can't place primary key columns on an inherited " + "class with no table." + ) + 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]) + ) + inherited_table.append_column(c) + if inherited_mapped_table is not None and \ + inherited_mapped_table is not inherited_table: + inherited_mapped_table._refresh_for_new_column(c) def _prepare_mapper_arguments(self): properties = self.properties @@ -401,20 +489,31 @@ class _MapperConfig(object): properties[k] = [col] + p.columns result_mapper_args = mapper_args.copy() result_mapper_args['properties'] = properties - return result_mapper_args + self.mapper_args = result_mapper_args def map(self): - mapper_args = self._prepare_mapper_arguments() - self.cls.__mapper__ = self.mapper_cls( + self._prepare_mapper_arguments() + if hasattr(self.cls, '__mapper_cls__'): + mapper_cls = util.unbound_method_to_callable( + self.cls.__mapper_cls__) + else: + mapper_cls = mapper + + self.cls.__mapper__ = mp_ = mapper_cls( self.cls, self.local_table, - **mapper_args + **self.mapper_args ) + del mp_.class_manager.info['declared_attr_reg'] + return mp_ class _DeferredMapperConfig(_MapperConfig): _configs = util.OrderedDict() + def _early_mapping(self): + pass + @property def cls(self): return self._cls() @@ -466,7 +565,7 @@ class _DeferredMapperConfig(_MapperConfig): def map(self): self._configs.pop(self._cls, None) - super(_DeferredMapperConfig, self).map() + return super(_DeferredMapperConfig, self).map() def _add_attribute(cls, key, value): |