What are Django signals and how do I use them?

What are Django signals and how do I use them?

Django signals are a way to allow decoupled applications to get notified when certain actions occur elsewhere in the application. You can use them to trigger actions automatically when events happen, like saving a model instance.

Can you give me an example of how to connect a signal to a model?

Sure! You can connect a signal to a model by using the @receiver decorator. For example, to perform an action after a model instance is saved, you can do this:

from django.db.models.signals import post_save
from django.dispatch import receiver

@receiver(post_save, sender=MyModel)
def my_handler(sender, instance, created, **kwargs):
    if created:
        print('A new instance was created!')

What are some common signals I should know about?

Some common signals in Django include pre_save, post_save, pre_delete, and post_delete. Each of these signals allows you to perform actions before or after a model instance is saved or deleted.

How can I disconnect a signal?

You can disconnect a signal using the disconnect method. For example:

post_save.disconnect(my_handler, sender=MyModel)