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pythondjangodjango-modelsdjango-signalsdjango-sessions

Django: determine which user is deleting when using post_delete signal


I want admins to be notified when certain objects are deleted but I also want to determine which user is performing the delete.

Is it possible?

This is the code:

# models.py
# signal to notify admins when nodes are deleted
from django.db.models.signals import post_delete
from settings import DEBUG

def notify_on_delete(sender, instance, using, **kwargs):
    ''' Notify admins when nodes are deleted. Only for production use '''
    if DEBUG:
        #return False
        pass
    # prepare context
    context = {
        'node': instance,
        'site': SITE
    }
    # notify admins that want to receive notifications
    notify_admins(instance, 'email_notifications/node-deleted-admin_subject.txt', 'email_notifications/node-deleted-admin_body.txt', context, skip=False)

post_delete.connect(notify_on_delete, sender=Node)

Solution

  • I doubt it's possible using the built-in signals (there is no User implicitly tied to a delete operation, and because of Django's loose coupling the database layer doesn't deal with HttpRequest objects). I would create my own signal which provides a user argument and send it in whatever view the delete operation takes place, something like:

    # myapp/signals.py
    from django.dispatch import Signal
    my_post_delete = Signal(providing_args=['instance', 'user'])
    
    # myapp/models.py
    from myapp.signals import my_post_delete
    ...
    my_post_delete.connect(notify_on_delete, sender=Node)
    
    # myapp/views.py
    from myapp.signals import my_post_delete
    ...
    @login_required
    def my_delete_view(request, ...)
        ...
        instance = Node.objects.get(...)
        instance.delete()
        my_post_delete.send(sender=Node, instance=instance, user=request.user)