Django Rest Framework: Disable field update after object is created

Question

I\'m trying to make my User model RESTful via Django Rest Framework API calls, so that I can create users as well as update their profiles.

However, as I go through

Answer 1

Another method would be to add a validation method, but throw a validation error if the instance already exists and the value has changed:

def validate_foo(self, value):                                     
    if self.instance and value != self.instance.foo:
        raise serializers.ValidationError("foo is immutable once set.")
    return value         

In my case, I wanted a foreign key to never be updated:

def validate_foo_id(self, value):                                     
    if self.instance and value.id != self.instance.foo_id:            
        raise serializers.ValidationError("foo_id is immutable once set.")
    return value         

See also: Level-field validation in django rest framework 3.1 - access to the old value