[Answer]-How to do validation on django's ManyRelatedManager?

by

1👍

Yes but don’t do it that way.

1) Use can use an explicit intermediate model for your M2M relationship and
provide it with a custom manager in which you can replace the create method.

2) In my opinion though, the best way is to have on one of these models an
instance method add_something which provides the necessary validation and exception-handling
logic.

👤rantanplan

0👍

I found a similar question, that is not exactly what I wanted, but helps as a workaround.

@receiver(m2m_changed, sender=MyModel.my_field.through)
def check(sender, **kwargs):
    if kwargs['action'] == 'pre_add':
        add = AnotherModel.objects.filter(pk__in=kwargs["pk_set"]) # instances being added
        # your validation here...

Thanks to mamachanko on his question.

👤zVictor

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