Why is `data` empty in nested serializer validate method?

Question

I am using Django REST Framework. I have a parent serializer class like so:

class MyParentSerializer(serializers.Serializer):

  # Use custom serializer as a field.
  my_field = MyFieldSerializer(
      required=False,
  )

  name = serializers.Charfield()
}

  def validate(data):
    # validation logic

And then my child serializer that is used above looks like this:

class MyFieldSerializer(serializers.Serializer):

    email_address = serializers.ListField(
        required=False,
        child=serializers.CharField(),
    )

    phone_number = serializers.ListField(
        required=False,
    )

    def validate(self, data):
        data <-- <-- This is empty if I pass in random invalid data!
        check_for_undefined_fields(self.data, self.fields)
        return data

Now, I pass the following data:

{
  "my_field": { "invalid_field": "foo"},
  "name": "bar"
}

However, if I check data in the validate method in my MyFieldSerializer class during validation, IT'S EMPTY!

Why? How can I fix this so that data is actually the data I passed?

Muhammad Hassan · Accepted Answer · 2020-01-28 19:45:56Z

2

Only fields which you have declared will be available in validate or is_valid or create methods. If you need to access those fields, you can use self.initial_data.

answered Jan 28, 2020 at 19:45

Muhammad Hassan

14.5k7 gold badges37 silver badges55 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

ritratt Over a year ago

So how do I make sure that no undefined fields are passed in my child serializer?

Muhammad Hassan Over a year ago

You will have to do this in your parent serializer validate method.

Mirza715 · Accepted Answer · 2020-01-29 09:40:19Z

2

You are not using ModelSerializer so every field in request have to be added in Serializer. In you case you just have to define invalid_field

  class MyFieldSerializer(serializers.Serializer):

    email_address = serializers.ListField(
        required=False,
        child=serializers.CharField(),
    )

    phone_number = serializers.ListField(
        required=False,
    )
    invalid_field = serializers.CharField()

    def validate(self, data):
        data <-- <-- This is empty if I pass in random invalid data!
        check_for_undefined_fields(self.data, self.fields)
        return data

answered Jan 29, 2020 at 9:40

Mirza715

4205 silver badges15 bronze badges

1 Comment

ritratt Over a year ago

But this means if I pass invalid_field it will work but if I pass invalid_field_foo or any other string then it wont work. Which is what I want it to validate -> If any field other than the ones defined is encountered then throw an error,

Sarthak Bhatia · Accepted Answer · 2020-12-21 01:48:30Z

0

In the nested serializer, you might be writing the nested field in create which you have set to read_only=True. Change that to read_only=False will solve the problem.

For e.g: question_response = QuestionResponseSerializer(many=True, read_only=True)

Change this to: question_response = QuestionResponseSerializer(many=True, read_only=False)

answered Dec 21, 2020 at 1:48

Sarthak Bhatia

11 silver badge1 bronze badge

Collectives™ on Stack Overflow

Why is `data` empty in nested serializer validate method?

3 Answers 3

2 Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related