Readonly for existing items only in Django admin inline

Question

I have a tabular inline model in the Django admin. I need 1 of the fields to not be changeable after it has been created, but setting it as readonly (via readonly_fields) wh

Answer 1

Here's a better read-only widget that I've used before:
https://bitbucket.org/stephrdev/django-readonlywidget/

from django_readonlywidget.widgets import ReadOnlyWidget

class TestAdmin(admin.ModelAdmin):
    def formfield_for_dbfield(self, db_field, **kwargs):
        field = super(TestAdmin, self).formfield_for_dbfield(db_field, **kwargs)
        if field:
            field.widget = ReadOnlyWidget(db_field=db_field)
        return field