def entity_setstate(entity, d):
"""Set the state of an SQLAlchemy entity
In:
- ``entity`` -- the newly created and not yet initialized SQLAlchemy entity
- ``d`` -- the state dictionary (created by ``entity_getstate()``)
"""
# Copy the _not_ SQLAlchemy managed attributes to our entity
key = d.pop('_sa_key', None)
entity.__dict__.update(d)
if key is not None:
# Fetch a new and initialized SQLAlchemy from the database
x = session.query(entity.__class__).get(key)
session.expunge(x)
# Copy its state to our entity
entity.__dict__.update(x.__dict__)
# Adjust the entity SQLAlchemy state
state = x._sa_instance_state.__getstate__()
state['instance'] = entity
entity._sa_instance_state.__setstate__(state)
# Add the entity to the current database session
session.add(entity)
def entity_setstate(entity, d):
"""Set the state of an SQLAlchemy entity
In:
- ``entity`` -- the newly created and not yet initialized SQLAlchemy entity
- ``d`` -- the state dictionary (created by ``entity_getstate()``)
"""
# Copy the _not_ SQLAlchemy managed attributes to our entity
key = d.pop('_sa_key', None)
entity.__dict__.update(d)
if key is not None:
# Fetch a new and initialized SQLAlchemy from the database
x = session.query(entity.__class__).get(key)
session.expunge(x)
# Copy its state to our entity
entity.__dict__.update(x.__dict__)
# Adjust the entity SQLAlchemy state
state = x._sa_instance_state.__getstate__()
state['instance'] = entity
entity._sa_instance_state.__setstate__(state)
# Add the entity to the current database session
session.add(entity)
def expunge(self, entity_instance):
"""Expunge the entity from the session"""
from sqlalchemy.orm.session import Session
session = Session.object_session(entity_instance)
if session:
session.expunge(entity_instance)
def delete(self, entity_instance):
"""Delete an entity instance"""
from sqlalchemy.orm.session import Session
session = Session.object_session(entity_instance)
#
# new and deleted instances cannot be deleted
#
if session:
if entity_instance in session.new:
session.expunge(entity_instance)
elif (entity_instance not in session.deleted) and (
entity_instance in session
): # if the object is not in the session, it might allready be deleted
history = None
#
# only if we know the primary key, we can keep track of its history
#
primary_key = self.mapper.primary_key_from_instance(entity_instance)
#
# we can only store history of objects where the primary key has only
# 1 element
# @todo: store history for compound primary keys
#
if not None in primary_key and len(primary_key) == 1:
pk = primary_key[0]
# save the state before the update
from camelot.model.memento import BeforeDelete
# only register the delete when the camelot model is active
if hasattr(BeforeDelete, "query"):
from camelot.model.authentication import getCurrentAuthentication
history = BeforeDelete(
model=unicode(self.entity.__name__),
primary_key=pk,
previous_attributes={},
authentication=getCurrentAuthentication(),
)
entity_instance.delete()
session.flush([entity_instance])
if history:
Session.object_session(history).flush([history])
def delete(self, entity_instance):
"""Delete an entity instance"""
from sqlalchemy.orm.session import Session
session = Session.object_session(entity_instance)
#
# new and deleted instances cannot be deleted
#
if session:
if entity_instance in session.new:
session.expunge(entity_instance)
elif (entity_instance not in session.deleted) and \
(entity_instance in session): # if the object is not in the session, it might allready be deleted
history = None
#
# only if we know the primary key, we can keep track of its history
#
primary_key = self.mapper.primary_key_from_instance(
entity_instance)
#
# we can only store history of objects where the primary key has only
# 1 element
# @todo: store history for compound primary keys
#
if not None in primary_key and len(primary_key) == 1:
pk = primary_key[0]
# save the state before the update
from camelot.model.memento import BeforeDelete
# only register the delete when the camelot model is active
if hasattr(BeforeDelete, 'query'):
from camelot.model.authentication import getCurrentAuthentication
history = BeforeDelete(
model=unicode(self.entity.__name__),
primary_key=pk,
previous_attributes={},
authentication=getCurrentAuthentication())
entity_instance.delete()
session.flush([entity_instance])
if history:
Session.object_session(history).flush([history])
def expunge(self, entity_instance):
"""Expunge the entity from the session"""
from sqlalchemy.orm.session import Session
session = Session.object_session(entity_instance)
if session:
session.expunge(entity_instance)
