django: How to hook save button for Model admin?

Question

I have a Model with a "status" field. When the user users the Admin app to modify an instance, how to I hook onto the "Save" button click so that I could update "status" to a value that's dependent on the logged in user's username?

Answer 1

Use the pre_save signal. Granted, it will be called on every instance save operation, not only from admin, but it does apply to your situation.

Answer 2

ModelAdmin.save_model() provides just what I need

Answer 3

Override your modeladmin's save_model-method:

class ModelAdmin(admin.ModelAdmin):

def save_model(self, request, obj, form, change):
    user = request.user 
    instance = form.save(commit=False)
    if not change:    # new object
        instance.status = ....
    else:             # updated old object
        instance.status = ...
    instance.save()
    form.save_m2m()
    return instance