根据其他字段在序列化程序中添加字段：Django

Question

我有一个seriliazer：

class aaaser(serializers.ModelSerializer):
    client_code = serializers.SerializerMethodField()
    status = serializers.SerializerMethodField()
    
    def get_status(self, obj):
        status_code = obj.status if obj.status else -1
        return status_code

    class Meta:
        model = models.Order
        fields = ('client_code', 'status', 'order_id', 'details')

在这个seriliazer中，我想添加一个名为cancel_reason的字段，只有当值为status == 5时才应该添加该字段

class aaaser(serializers.ModelSerializer):
    client_code = serializers.SerializerMethodField()
    status = serializers.SerializerMethodField()
    
    def get_status(self, obj):
        status_code = obj.status if obj.status else -1
        if status_code == 5:
            # this felt dumb but had to try!
            cancel_reason = serializers.SerializerMethodField()
        return status_code

    def get_cancel_reason(self, obj):
        return "Dummy-reason"

    class Meta:
        model = models.Order
        fields = ('client_code', 'status', 'order_id', 'details')

^This Doesn't work

请为这个用例建议一个解决方案或替代方案。。非常感谢

Answer 1

你可以这样做

class aaaser(serializers.ModelSerializer):
    client_code = serializers.SerializerMethodField()
    status = serializers.SerializerMethodField()

    def get_status(self, obj):
        status_code = obj.status if obj.status else -1
        if status_code == 5:
            self.fields['cancel_reason'] = serializers.SerializerMethodField()
        return status_code

如前所述here关于如何在序列化程序中添加动态字段