diff options
Diffstat (limited to 'lib/sqlalchemy/orm/strategies.py')
| -rw-r--r-- | lib/sqlalchemy/orm/strategies.py | 56 |
1 files changed, 36 insertions, 20 deletions
diff --git a/lib/sqlalchemy/orm/strategies.py b/lib/sqlalchemy/orm/strategies.py index 21f22ef50..ec2c3c2bc 100644 --- a/lib/sqlalchemy/orm/strategies.py +++ b/lib/sqlalchemy/orm/strategies.py @@ -8,7 +8,7 @@ implementations, and related MapperOptions.""" from sqlalchemy import exc as sa_exc -from sqlalchemy import sql, util, log +from sqlalchemy import sql, util, log, event from sqlalchemy.sql import util as sql_util from sqlalchemy.sql import visitors, expression, operators from sqlalchemy.orm import mapper, attributes, interfaces, exc as orm_exc @@ -17,7 +17,7 @@ from sqlalchemy.orm.interfaces import ( LoaderStrategy, StrategizedOption, MapperOption, PropertyOption, serialize_path, deserialize_path, StrategizedProperty ) -from sqlalchemy.orm import session as sessionlib +from sqlalchemy.orm import session as sessionlib, unitofwork from sqlalchemy.orm import util as mapperutil from sqlalchemy.orm.query import Query import itertools @@ -38,22 +38,36 @@ def _register_attribute(strategy, mapper, useobject, prop = strategy.parent_property attribute_ext = list(util.to_list(prop.extension, default=[])) - + + listen_hooks = [] + if useobject and prop.single_parent: - attribute_ext.insert(0, _SingleParentValidator(prop)) + listen_hooks.append(single_parent_validator) if prop.key in prop.parent._validators: - attribute_ext.insert(0, - mapperutil.Validator(prop.key, prop.parent._validators[prop.key]) + listen_hooks.append( + lambda desc, prop: mapperutil._validator_events(desc, + prop.key, + prop.parent._validators[prop.key]) ) if useobject: - attribute_ext.append(sessionlib.UOWEventHandler(prop.key)) + listen_hooks.append(unitofwork.track_cascade_events) + # need to assemble backref listeners + # after the singleparentvalidator, mapper validator + backref = kw.pop('backref', None) + if backref: + listen_hooks.append( + lambda desc, prop: attributes.backref_listeners(desc, + backref, + uselist) + ) + for m in mapper.self_and_descendants: if prop is m._props.get(prop.key): - attributes.register_attribute_impl( + desc = attributes.register_attribute_impl( m.class_, prop.key, parent_token=prop, @@ -71,6 +85,9 @@ def _register_attribute(strategy, mapper, useobject, doc=prop.doc, **kw ) + + for hook in listen_hooks: + hook(desc, prop) class UninstrumentedColumnLoader(LoaderStrategy): """Represent the a non-instrumented MapperProperty. @@ -1237,11 +1254,8 @@ class LoadEagerFromAliasOption(PropertyOption): ("user_defined_eager_row_processor", interfaces._reduce_path(paths[-1]))] = adapter -class _SingleParentValidator(interfaces.AttributeExtension): - def __init__(self, prop): - self.prop = prop - - def _do_check(self, state, value, oldvalue, initiator): +def single_parent_validator(desc, prop): + def _do_check(state, value, oldvalue, initiator): if value is not None: hasparent = initiator.hasparent(attributes.instance_state(value)) if hasparent and oldvalue is not value: @@ -1249,14 +1263,16 @@ class _SingleParentValidator(interfaces.AttributeExtension): "Instance %s is already associated with an instance " "of %s via its %s attribute, and is only allowed a " "single parent." % - (mapperutil.instance_str(value), state.class_, self.prop) + (mapperutil.instance_str(value), state.class_, prop) ) return value - def append(self, state, value, initiator): - return self._do_check(state, value, None, initiator) - - def set(self, state, value, oldvalue, initiator): - return self._do_check(state, value, oldvalue, initiator) - + def append(state, value, initiator): + return _do_check(state, value, None, initiator) + def set_(state, value, oldvalue, initiator): + return _do_check(state, value, oldvalue, initiator) + + event.listen(desc, 'on_append', append, raw=True, retval=True, active_history=True) + event.listen(desc, 'on_set', set_, raw=True, retval=True, active_history=True) + |