Assign User-objects To A Group While Editing Group-object In Django Admin

Answer :

The save method above won't work if you add a new group and simultaneously add users to the group. The problem is that the new group won't get saved (the admin uses commit=False) and won't have a primary key. Since the purpose of save_m2m() is to allow the calling view to handle saving m2m objects, I made a save object that wraps the old save_m2m method in a new method.

def save(self, commit=True):     group = super(GroupAdminForm, self).save(commit=commit)      if commit:         group.user_set = self.cleaned_data['users']     else:         old_save_m2m = self.save_m2m         def new_save_m2m():             old_save_m2m()             group.user_set = self.cleaned_data['users']         self.save_m2m = new_save_m2m     return group 

yourapp/admin.py

from django import forms from django.contrib import admin from django.utils.translation import ugettext_lazy as _ from django.contrib.admin.widgets import FilteredSelectMultiple  from django.contrib.auth.models import User, Group  class GroupAdminForm(forms.ModelForm):     users = forms.ModelMultipleChoiceField(         queryset=User.objects.all(),          required=False,         widget=FilteredSelectMultiple(             verbose_name=_('Users'),             is_stacked=False         )     )      class Meta:         model = Group      def __init__(self, *args, **kwargs):         super(GroupAdminForm, self).__init__(*args, **kwargs)          if self.instance and self.instance.pk:             self.fields['users'].initial = self.instance.users.all()      def save(self, commit=True):         group = super(GroupAdminForm, self).save(commit=False)          if commit:             group.save()          if group.pk:             group.users = self.cleaned_data['users']             self.save_m2m()          return group  class GroupAdmin(admin.ModelAdmin):     form = GroupAdminForm  admin.site.unregister(Group) admin.site.register(Group, GroupAdmin)