Collecting additional information in the Django administration page?

Question

on save if user select certain option i want to take user to a page where he can have one more field to be filled and then redirect to admin default page

Answer 1

Rather than redirect to a new page you can simply override the form that the create and update pages use. This lets you add additional fields to the modelform, keeping all your form processing in one place.

First you'll need to set up your ModelAdmin to use the custom form:

admin.py

from django.contrib import admin
from forms import BookAdminForm
from models import Book

class BookAdmin(admin.ModelAdmin):
    form = BookAdminForm

admin.site.register(Book, BookAdmin)

forms.py

from django import forms

class BookAdminForm(forms.ModelForm):
    additional_field = forms.CharField(max_length=100)

    class Meta:
        model = Book

Next, you'll need to override the save method to check if the "certain option" is selected then handle the extra field appropriately. Inside your class you'll need something like this:

def save(self, *args, **kwargs):
    if self.cleaned_data['certain_field'].value == 'certain option':
        # process additional_field
    # don't forget to call super to save the rest of the form
    super(BookAdminForm, self).save(*arg, **kwargs)

NOTE: This code is untested, but it should point you in the right direction.

It is also possible to override the save_model() method in the ModelAdmin.