Django Rest Framework: pass user from view to serializer

Question

I have such view for user change password:

class ChangePasswordView(generics.UpdateAPIView):
    serializer_class = ChangePasswordSerializer
    permission_classes = [IsAuthenticated]

        def put(self, request, *args, **kwargs):
            data = request.data.copy()
            data['user'] = self.request.user
            serializer = self.get_serializer(data=data)
            serializer.is_valid(raise_exception=True)
            user = serializer.validated_data['user']
            user.set_password(serializer.validated_data["new_password"])
            user.save()
            return Response(status=status.HTTP_204_NO_CONTENT)

And serializer for this view looks like this:

class ChangePasswordSerializer(serializers.Serializer):
    old_password = serializers.CharField()
    new_password = serializers.CharField()
    new_password_retyped = serializers.CharField()

    def validate(self, data):
        old_password = data.get('old_password')
        new_password = data.get('new_password')
        new_password_retyped = data.get('new_password_retyped')
        user = data.get('user')

        # misc validation checks

        data['user'] = user
        return data

and my problem is that user object is not being passed to serializer, tried printing it to see content of data inside put:

<QueryDict: {'old_password': ['testpassword'], 'new_password': ['testpassword1'], 'new_password_retyped': ['testpassword1'], 'user': [<User: root>]}>

and inside serializer:

OrderedDict([('old_password', 'testpassword'), ('new_password', 'testpassword1'), ('new_password_retyped', 'testpassword1')])

As you can see, user is missing. First, I thought that it may have something to do with passing object to serializer so I changed data['user'] = self.request.user to data['user'] = self.request.user.username so it would only pass string with username, but with no luck

Answer 1

You cannot pass user to serializer this way because serializers drop data which is not relevent. Try doing something like this.

class ChangePasswordSerializer(serializers.Serializer):
    old_password = serializers.CharField()
    new_password = serializers.CharField()
    new_password_retyped = serializers.CharField()

    def __init__(self, *args, **kwargs):
        self.user = kwargs.pop('user')
        super().__init__(*args, **kwargs)

    def validate(self, data):
        old_password = data.get('old_password')
        new_password = data.get('new_password')
        new_password_retyped = data.get('new_password_retyped')
        user = self.user

        # misc validation checks

        data['user'] = user
        return data

And pass user to serializer separately.

self.get_serializer(data=data, user=self.request.user)