Overload ModelMultipleChoiceField __init__ for many to many - django

Question

I have something working but I am sure it's not the best way of doing it because I have duplicated code.
It's a widget to display checkboxes for groups that clients can belong to. A client can belong to multiple groups.
I am sure I have messed up the overloading of the widget somehow.
models.py
class Client(models.Model):
name = models.CharField(u'Name', max_length=250, unique=True)
groups = models.ManyToManyField('ClientGroup', related_name="client")
def __unicode__(self):
return self.name
class ClientGroup(models.Model):
name = models.CharField(u'Name', max_length=250, unique=True)
def __unicode__(self):
return self.name
forms.py
# -*- coding: utf-8 -*-
from django import forms
from models import ClientGroup
class ClientGroupForm(forms.ModelForm):
class Meta:
model = ClientGroup
fields = ('groups',)
groups = forms.ModelMultipleChoiceField(queryset=ClientGroup.objects.all(),
widget=forms.CheckboxSelectMultiple(),
label='',
required=False)
def __init__(self, client_id = None, *args, **kwargs):
super(ClientGroupForm, self).__init__(*args, **kwargs)
if client_id:
self.fields['groups'] = forms.ModelMultipleChoiceField(queryset = ClientGroup.objects.all(),
initial=ClientGroup.objects.filter(client = client_id),
widget=forms.CheckboxSelectMultiple(),
label='',
required=False)
def __unicode__(self):
return self.groups
views.py
def client(request, pk = 0):
client={}
if pk != 0:
client = Client.objects.get(pk = pk)
groupsForm = ClientGroupForm(pk)
context = {'client':client, 'groupsForm': groupsForm}
return render(request, 'client.html', context)
Can anyone show me a better way of coding the forms.py?
Thanks

Answer 1

You could replace
class ClientGroupForm(forms.ModelForm):
# stuff
def __init__(self, client_id = None, *args, **kwargs):
super(ClientGroupForm, self).__init__(*args, **kwargs)
if client_id:
self.fields['groups'] = forms.ModelMultipleChoiceField(queryset = ClientGroup.objects.all(),
initial=ClientGroup.objects.filter(client = client_id),
widget=forms.CheckboxSelectMultiple(),
label='',
required=False)
with
class ClientGroupForm(forms.ModelForm):
# stuff
def __init__(self, *args, **kwargs):
self.client_id = kwargs.get('client_id', None)
super(ClientGroupForm, self).__init__(*args, **kwargs)
if client_id:
self.fields['groups'].queryset = ClientGroup.objects.filter(client=client_id)