What is it?

A library that will send signals on queryset data manipulation methods.

What problem does it solve?

Django sends many signals, including when a model instance is created, deleted and updated. However when using bulk methods like bulk_create or delete. There is no signal send, with this library signals are send on the following methods:

• bulk_create

• delete

• get_or_create

• update_or_create

• update

A signal will be send before and after the method is executed.

How do I install it?

pip install django-query-signals

>>> import django_integrator
>>> django_integrator.add_application('django_query_signals')

How do I use it?

From the namespace django_query_signals you can import the below signals which you can connect to via the usual way.

• pre_bulk_create

• post_bulk_create,

• pre_delete

• post_delete

• pre_get_or_create

• post_get_or_create

• pre_update_or_create

• post_update_or_create

• pre_update

• post_update

For example:

>>> @receiver(post_bulk_create)
>>> def callback(signal, sender, args):
>>>       pass

The argument ‘signal’ is the signal that is connected, ‘sender’ is the underlying model class and ‘args’ is a dictionary which the method in queryset is called with, this is supplemented with ‘self’ which contains the queryset instance and if the connecting signal is a ‘post’ type the key ‘return’ is also added which contains the value the method has returned.

If you connect to the ‘pre’ type signal, changing the ‘args’ and ‘self’ will also change the actual execution of the method.

Caveat

This library relies on monkey patching django.db.models.query.QuerySet, thus if your instance also monkey patches the same thing or you use a custom QuerySet in your Manager, then there is a good chance that this library will not work at all for you, however most likely you can work around this issue by examining the signals.py file in this library.

What license is this?

Two-clause BSD

How can I get support?

Please use the repo’s bug tracker to leave behind any questions, feedback, suggestions and comments. I will handle them depending on my time and what looks interesting. If you require guaranteed support please contact me via e-mail so we can discuss appropriate compensation.

Signing Off

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https://paypal.me/MartinHellwig

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Thank you!