2.7. Signals¶
New in version 0.5.
Note
Signal support is provided by the excellent blinker library and will gracefully fall back if it is not available.
The following document signals exist in MongoEngine and are pretty self-explanatory:
- mongoengine.signals.pre_init
- mongoengine.signals.post_init
- mongoengine.signals.pre_save
- mongoengine.signals.post_save
- mongoengine.signals.pre_delete
- mongoengine.signals.post_delete
- mongoengine.signals.pre_bulk_insert
- mongoengine.signals.post_bulk_insert
Example usage:
from mongoengine import *
from mongoengine import signals
class Author(Document):
name = StringField()
def __unicode__(self):
return self.name
@classmethod
def pre_save(cls, sender, document, **kwargs):
logging.debug("Pre Save: %s" % document.name)
@classmethod
def post_save(cls, sender, document, **kwargs):
logging.debug("Post Save: %s" % document.name)
if 'created' in kwargs:
if kwargs['created']:
logging.debug("Created")
else:
logging.debug("Updated")
signals.pre_save.connect(Author.pre_save, sender=Author)
signals.post_save.connect(Author.post_save, sender=Author)
2.7.1. ReferenceFields and signals¶
Currently reverse_delete_rules do not trigger signals on the other part of the relationship. If this is required you must manually handled the reverse deletion.