Object's ManyToMany relationship is not updated inside signals - django

Question

I have this singal
#receiver(post_save, sender=Organization)
def save_tags(sender, instance, **kwargs):
from .views import post
text_input_tags = post.getlist('tags1')[0]
text_input_tags = text_input_tags.strip()
text_inputs_tags = text_input_tags.split(' ')
for tag in text_inputs_tags:
if not tag.startswith('#') :
tag = '#' + tag
tag_obj = Tag.objects.get_or_create(name = tag)[0]#.organization_set.set([obj,])
tag_obj.save()
instance.tags.add(tag_obj)
print(instance.tags.all())
from the views I am importing the post data to use inside the signal.
There is a manytomany relationship between two models Organization and Tag.
I am trying to get some attributes from the post request and create a Tag object from them, then after that add that Tag object into the ManyToMany relationship of the instance of the Organization.
when I print the tags of the organization instance
print(instance.tags.all())
I get the added instances in the QuerySet, but it's not saved in the organization instance and I don't understand why...
I tried to make that same functionality inside a method of UpdateView of the Organization, but it did the exact same thing and didn't work.
This is the UpdateView and its methods that doesn't work with this functionality
class OrganizationUpdate(UpdateView):
model = Organization
'''fields = [
'name',
'slug',
'bio',
'avatar_thumbnail',
'location',
'tags',
'contact_information'
]'
'''
form_class = forms.OrganizationForm
def get_object(self):
obj = Organization.objects.get(slug = self.kwargs.get('slug'))
if self.request.user not in obj.moderators.all() :
raise exceptions.PermissionDenied()
return obj
def save(self, *args, **kwargs):
org = self.get_object()
POST = self.request.POST.copy()
text_input_tags = POST.getlist('tags1')[0]
text_input_tags = text_input_tags.strip()
text_inputs_tags = text_input_tags.split(' ')
for tag in text_inputs_tags:
print(tag)
if not tag.startswith('#') :
tag = '#' + tag
tag_obj = Tag.objects.get_or_create(name = tag)[0]
tag_obj.save()
org.tags.add(tag_obj)
return super().save(*args, **kwargs)
def post(self, request, *args, **kwargs):
# same functionality in save()
return super().post(request, *args, **kwargs)
def form_valid(self, form):
# same functionality in save()
return super().form_valid(form)

Answer 1

Actually all I needed to do is to implement this functionality after all the saving of the instance has been done, so the post or form_valid methods don't apply here, I needed to implement it inside a method that happens in the last parts of the updateview, my choice was inside the get_success_url, the code looks like the following:
def get_success_url(self):
org = self.get_object()
POST = self.request.POST.copy()
text_input_tags = POST.getlist('tags1')[0]
text_input_tags = text_input_tags.strip()
text_inputs_tags = text_input_tags.split(' ')
for tag in text_inputs_tags:
print(tag)
if not tag.startswith('#') :
tag = '#' + tag
tag_obj = Tag.objects.get_or_create(name = tag)[0]
tag_obj.save()
org.tags.add(tag_obj)
return super().get_success_url()