[Django]-Editing django-rest-framework serializer object before save

34👍

You can edit the serializer’s object before save the serializer:

if serializer.is_valid():
    serializer.object.user_id = 15 # <----- this line
    serializer.save()
👤zephyr

79👍

Now edited for REST framework 3

With REST framework 3 the pattern is now:

if serializer.is_valid():
    serializer.save(user_id=15)

Note that the serializers do not now ever expose an unsaved object instance as serializer.object, however you can inspect the raw validated data as serializer.validated_data.

If you’re using the generic views and you want to modify the save behavior you can use the perform_create and/or perform_update hooks…

def perform_create(self, serializer):
    serializer.save(user_id=15)

0👍

Just in case you need to modify the data before validation, there is another option without needing to override the functions create or perform_create. Just use the to_internal_value function on your serializers class:

class MySerializer(serializers.ModelSerializer):
    class Meta:
        model = MyModel
    def to_internal_value(self, data):
        data['field1'] = "new value for field 1"
        data['field2'] = "new value for field 2"
        data['field3'] = "new value for field 3"
        return super().to_internal_value(data)

So we can modify the data before doing the validation.

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