[Django]-How to make a model instance read-only after saving it once?

You can check if it is creation or update in the model’s save method:

def save(self, *args, **kwargs):
    if self.pk:
        raise StandardError('Can\'t modify bla bla bla.')
    super(Payment, self).save(*args, **kwargs)

Code above will raise an exception if you try to save an existing object. Objects not previously persisted don’t have their primary keys set.

Suggested reading: The Zen of Admin in chapter 17 of the Django Book.

Summary: The admin is not designed for what you’re trying to do

However, the 1.0 version of the book covers only Django 0.96, and good things have happened since.

In Django 1.0, the admin site is more customizable. Since I haven’t customized admin myself, I’ll have to guess based on the docs, but I’d say overriding the model form is your best bet.

use readonlyadmin in ur amdin.py.List all the fields which u want to make readonly.After creating the object u canot edit them then

use the link

http://www.djangosnippets.org/snippets/937/

copy the file and then import in ur admin.py and used it

What you can easily do, is making all fields readonly:

class MyModelAdmin(ModelAdmin):
    form = ...
    def get_readonly_fields(self, request, obj=None):
        if obj:
            return MyModelAdmin.form.Meta.fields
        else: # This is an addition
            return []

As for making the Save disappear, it would be much easier if

1. has_change_permission returning False wouldnt disable even displaying the form
2. the code snippet responsible for rendering the admin form controls (the admin_modify.submit_row templatetag), wouldnt use show_save=True unconditionally.

Anyways, one way of making that guy not to be rendered :

1. Create an alternate version of has_change_permission, with proper logic:

   class NoSaveModelAdminMixin(object):
       def render_change_form(self, request, context, add=False, change=False, form_url='', obj=None):
           response = super(NoSaveModelAdmin, self).render_change_form(request, context, add, change,form_url, obj)
           response.context_data["has_change_permission"] = self.has_real_change_permission(request, obj)
       def has_real_change_permission(self, request, obj):
           return obj==None
       def change_view(self, request, object_id, extra_context=None):
           obj = self.get_object(request, unquote(object_id))
           if not self.has_real_change_permission(request, obj) and request.method == 'POST':
               raise PermissionDenied 
           return super(NoSaveModelAdmin, self).change_view(request, object_id, extra_context=extra_context)
   

2. Override the submit_row templatetag similar to this:

   @admin_modify.register.inclusion_tag('admin/submit_line.html', takes_context=True)
   def submit_row(context):
       ...
           'show_save': context['has_change_permission']
       ...
   
   admin_modify.submit_row = submit_row