Add Content from a Custom View to the Django Admin Change Form

[jough]

I'd like to add a derived field to a default ModelAdmin.fieldsets like
I would by specifying a method and adding it to the
ModelAdmin.list_display property, but there doesn't seem to be an easy
way to do that (if there is ANY way to do that).

The default Django Admin list view seems to have a lot more options
than the change form view does.

Let's say I have two fields for a location: latitude and longitude,
and instead of displaying them on a change form I want to display a
Google Maps Static Map image instead - I already have a method that
will return the src url for the image - I just need a way to add that
image to the model change form instead of showing those two fields.

The documentation says you can add custom views to the admin forms,
but provides no guidance or examples, and I really just want to add a
derived field to a single model, not every instance of the change form
view.

[ringemup]

You can either create a custom widget and
ModelAdmin.formfield_overrides [1] or (if you need to customize the
data processing as well as the display, create a custom form and use
ModelAdmin.form [2].

[1] http://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.formfield_overrides
[2] http://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.form