How to restrict users voting on their own model

Question

I am using django-voting as a voting application for two of my models. Those both models have fields "author".

How can I restrict a user from voting on a model that has this particular user set as it's author without modifying django-voting app?

Django middleware is the first thing that comes to my mind, but I don't understand it's "proces_view" function. If you think middleware is the right way could you please give an example of how to do it.

Answer 1

Add this code anywhere in your settings.py:

from voting.managers import VoteManager

def check_user(func):
    def wrapper(self, obj, user, vote):
        if obj.user != user:
            return func(self, obj, user, vote)
        else:
            return None
            # or raise some exception
    return wrapper

VoteManager.record_vote = check_user(VoteManager.record_vote)

I didn't run this code, maybe it's incorrect, but I hope idea is clear

Answer 2

Rather than a middleware hack, why not reroute requests to that particular URI through another view? Then you can performs whatever logic you like, and subsequently call the original view if appropriate.

Answer 3

Another idea is to use the post_save signal

like so:

from django.db.models.signals import post_save
from voting.models import Vote

def check_user(sender, instance, **kwargs):
    if instance.user == instance.object.user:
        instance.delete()
        # do some other stuff to tell the user it didn't work

post_save.connect(check_user, sender=Vote)

The benefit of doing this vs overriding VoteManager.record_vote is that it's less tightly coupled to the voting module, and if they make changes it's less likely to break your code

edit: as in Glader's answer, you need to make sure that all the objects you're voting on have a 'user' attribute.