A signal m2m_changed and bug with post_remove

Question

I need to detect a post_remove signal, so I have written :

def handler1(sender, instance, action, reverse, model, pk_set, **kwargs):
if (action == \'post_rem         


        

Answer 1

I had reach a conclusion after long long time o seaching First my problem: I had some how update one atribute from my model to set it False when my m2m is is empty, and true if it have at least 1 item, so, the true thing works but when i try to "pre_remove" or "post_remove" never is trigged, so after some trys with some differents examples i saw something weird on this "pre_clear", each time i change my m2m this always has the last values, so i manage to force delete this values from my m2m and this way it trigger the pre_remove and post_remove, so this works for me, see bellow the code

So now i can automaticly set ativo True or False based on my m2m

class Servico(BaseMixin):
    descricao = models.CharField(max_length=50)

#This inheritance from User of django that has is_active boolean field
class UsuarioRM(Usuario):
    servicos = models.ManyToManyField(Servico,related_name='servicos_usuario', blank=True)

# SIGNALS
from django.db.models import signals
from django.db.models.signals import m2m_changed

def usuariorm_servicos_changed(sender, **kwargs):
    action = kwargs.pop('action', None)
    pk_set = kwargs.pop('pk_set', None)
    instance = kwargs.pop('instance', None)

    if action == "pre_clear":
        if instance.servicos.all():
        servicos = instance.servicos.all()
            for servico in servicos:
                instance.servicos.remove(servico)
            instance.save()
    else:
        instance.is_active = False
        instance.save() 
        if action == "post_add":
            if pk_set:
            instance.is_active = True 
        else:
            instance.is_active = False

        instance.save()

 m2m_changed.connect( usuariorm_servicos_changed, sender=UsuarioRM.servicos.through )