Consider signal dispatcher integration

[mattdennewitz]

MongoDB offers no relationship management, so post_save and post_delete signals (at the very least) would help keep denormalized data clean. Django has an excellent fork/refactoring of PyDispatcher, and PyDispatcher itself may fit the bill.

[iapain]

+1 and should be included in v0.4. Signal hooks needs to reside within ORM which means we need to alter quite a bit. I am okay with PyDispatcher but for sure we have to tweak a bit to fit into mongoengine.

[theojulienne]

I'm working on this now. So far I've extracted Django's dispatch framework into it's own project, and added an extra decorator. Tests and docs coming next.

theojulienne/mongoengine@ab24dcf

Usage:
from mongoengine.signals import post_save, post_delete

class SomeDocument(Document):
    ...

@post_save.receive( sender=SomeDocument )
def do_something_save( instance, *args, **kwargs ):
    print instance, 'was just saved'

@post_delete.receive( sender=SomeDocument )
def do_something_delete( instance, *args, **kwargs ):
    print instance, 'was just deleted'

[rozza]

This is now implemented in dev using blinker.