Opps I didn't know that subject has been changed. FYI, in 0.6.x, I used to play with class JSONType(MutableType, TypeDecorator) pretty well.
But 0.7.x, I'm not sure it works as well as 0.6.x... Regards, Tate -----Original Message----- From: Chris Withers <[email protected]> Sender: [email protected] Date: Fri, 24 Feb 2012 11:39:39 To: <[email protected]> Reply-To: [email protected] Subject: Bug in old-style mutable type? (was Re: [sqlalchemy] How can I tell SA that a mutable attribute has changed?) On 24/02/2012 10:49, Chris Withers wrote: > (Does SA have a JSONType now? we're using a homebrew one, that may be > where the problem lies...) For reference, I've included the code for this type at the end of this email, it uses MutableType, so the following should work: > obj = session.query(MyModel).one() > obj.config['foo'] += 1 > session.commit() > > ...on my dev machine, the change gets persisted. > Of course, on production machines, it does not :-( Are there known bugs in this? I see there's now a "new way" in 0.7, but that means you have to know the type of the object stored in the column rather than just "any json-serializable value" being okay. cheers, Chris PS: from sqlalchemy import String from sqlalchemy.types import MutableType, TypeDecorator import simplejson class JSONType(MutableType, TypeDecorator): """Column type which stores Python objects in JSON form. PickleType applies simplejson's ``dumps()`` to incoming objects, and ``loads()`` on the way out, allowing simple Python objects to be stored as a serialized text field. As it extends MutableType, changes in mutable objects will be detected and handled correctly. It is safe to use this column type to store lists, dicts and other mutable types. """ impl = String def process_bind_param(self, value, _): if value is None: return None return self._dumps(value) def process_result_value(self, value, _): if value is None: return None return self._loads(value) def copy_value(self, value): return self._loads(self._dumps(value)) def is_mutable(self): return True def _loads(self, strvalue): return simplejson.loads(str(strvalue), use_decimal=True) def _dumps(self, value): return simplejson.dumps(value, use_decimal=True) -- Simplistix - Content Management, Batch Processing & Python Consulting - http://www.simplistix.co.uk -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
