Validating a Django field dependently on context - django

Question

I write the code to edit the list of users which belong to a team. For this I create a form, as below:
class Organization(models.Model):
name = models.CharField(blank=False, verbose_name=_("Name"), help_text=_('Organization Name'), max_length=256)
class Team(models.Model):
organization = models.ForeignKey('Organization')
name = models.CharField(blank=False, verbose_name=_("Name"), help_text=_('Team Name'), max_length=256)
users = models.ManyToManyField('User', related_name='teams')
def __str__(self):
return self.name
class TeamUsersForm(forms.ModelForm):
class Meta:
model = Team
fields = ['users']
users = forms.ModelMultipleChoiceField(queryset=User.objects.filter(request.user.organization), required=False)
def clean_users(self):
users = self.cleaned_data['users']
if users.exclude(organization=request.user.organization):
raise ValidationError(_("Cannot add user from another organization"))
return users
The code above should look into request value to determine the current organization and restrict display and model store only to users from the same organization.
But the above code cannot work, because the value of request is not known at class loading time.
What do you suggest to do?
I thought of two variants:
create a local (to a function) class like the above class TeamUsersForm
dismiss using Django forms for this altogether and use more low-level API

Answer 1

Overide the __init__ of the TeamUsersForm and access request there.
class TeamUsersForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
self.request = kwargs.pop('request')
super().__init__(*args, **kwargs)
self.fields['users'] = forms.ModelMultipleChoiceField(queryset=User.objects.filter(self.request.user.organization), required=False)
This implies that when you instantiate your form, you should it this way:
# somewhere in your views.py, probably
f = TeamUsersForm(request.POST, request=request)