Remove "add another" in Django admin screen

Question

Whenever I'm editing object A with a foreign key to object B, a plus option "add another" is available next to the choices of object B. How do I remove that option?

I configured a user without rights to add object B. The plus sign is still available, but when I click on it, it says "Permission denied". It's ugly.

I'm using Django 1.0.2

Answer 1

Look at django.contrib.admin.options.py and check out the BaseModelAdmin class, formfield_for_dbfield method.

You will see this:

# For non-raw_id fields, wrap the widget with a wrapper that adds
# extra HTML -- the "add other" interface -- to the end of the
# rendered output. formfield can be None if it came from a
# OneToOneField with parent_link=True or a M2M intermediary.
if formfield and db_field.name not in self.raw_id_fields:
    formfield.widget = widgets.RelatedFieldWidgetWrapper(formfield.widget, db_field.rel, self.admin_site)

I think your best bet is create subclass of ModelAdmin (which in turn is a subclass of BaseModelAdmin), base your model on that new class, override formfield_fo_dbfield and make it so that it won't/or will conditionally wrap the widget in RelatedFieldWidgetWrapper.

One could argue that if you have a user that doesn't have rights to adding related objects, the RelatedFieldWidgetWrapper should not display the add link? Maybe this is something that is deserving of mention in Django trac?

Answer 2

Have you considered instead using CSS to simply not show the button? Maybe that's a little too hacky.

This is untested, but I'm thinking...

no-addanother-button.css

#_addanother { display: none }

admin.py

class YourAdmin(admin.ModelAdmin):
    # ...
    class Media:
        # edit this path to wherever
        css = { 'all' : ('css/no-addanother-button.css',) }

Django Doc for doing this -- Media as a static definition

Note/Edit: The documentation says the files will be prepended with the MEDIA_URL but in my experimentation it isn't. Your mileage may vary.

If you find this is the case for you, there's a quick fix for this...

class YourAdmin(admin.ModelAdmin):
    # ...
    class Media:
        from django.conf import settings
        media_url = getattr(settings, 'MEDIA_URL', '/media/')
        # edit this path to wherever
        css = { 'all' : (media_url+'css/no-addanother-button.css',) }