PYTHON

django serializer method field read write

class ProjectSerializer(serializers.ModelSerializer):
    contract_price = WritableSerializerMethodField(deserializer_field=serializers.DecimalField(max_digits=12, decimal_places=2))

    def get_contract_price(self, project):
        return project.contract_price

    def set_contract_price(self, value):
        return value

django serializer method field read write

class WritableSerializerMethodField(serializers.SerializerMethodField):
    def __init__(self, **kwargs):
        self.setter_method_name = kwargs.pop('setter_method_name', None)
        self.deserializer_field = kwargs.pop('deserializer_field')

        super().__init__(**kwargs)

        self.read_only = False

    def bind(self, field_name, parent):
        retval = super().bind(field_name, parent)
        if not self.setter_method_name:
            self.setter_method_name = f'set_{field_name}'

        return retval

    def get_default(self):
        default = super().get_default()

        return {
            self.field_name: default
        }

    def to_internal_value(self, data):
        value = self.deserializer_field.to_internal_value(data)
        method = getattr(self.parent, self.setter_method_name)
        return {self.field_name: self.deserializer_field.to_internal_value(method(value))}