Django RestFramework-如何在 ModelSerializer 中添加自定义字段

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最佳答案

除了 CharField(和其他类型化字段)用于可写字段之外，您做的是正确的。

在这种情况下，您只需要一个简单的只读字段，因此只需使用:

customField = Field(source='get_absolute_url')

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这里回答你的问题。你应加入你的模型帐户:

@property
def my_field(self):
return None

现在你可以使用:

customField = CharField(source='my_field')

来源: https://stackoverflow.com/a/18396622/3220916

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... 为了清楚起见，如果你有一个模型方法定义如下:

class MyModel(models.Model):
...


def model_method(self):
return "some_calculated_result"

您可以像下面这样将调用该方法的结果添加到序列化程序:

class MyModelSerializer(serializers.ModelSerializer):
model_method_field = serializers.CharField(source='model_method')

附言。由于自定义字段实际上不是模型中的字段，所以通常需要将其设置为只读，如下所示:

class Meta:
model = MyModel
read_only_fields = (
'model_method_field',
)

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With the last version of Django Rest Framework, you need to create a method in your model with the name of the field you want to add.

class Foo(models.Model):
. . .
def foo(self):
return 'stuff'
. . .


class FooSerializer(ModelSerializer):
foo = serializers.ReadOnlyField()


class Meta:
model = Foo
fields = ('foo',)

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为了显示 self.author.full_name，我在使用 Field时遇到了一个错误:

class CommentSerializer(serializers.HyperlinkedModelSerializer):
author_name = ReadOnlyField(source="author.full_name")
class Meta:
model = Comment
fields = ('url', 'content', 'author_name', 'author')

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In fact there a solution without touching at all the model. You can use SerializerMethodField which allow you to plug any method to your serializer.

class FooSerializer(ModelSerializer):
foo = serializers.SerializerMethodField()


def get_foo(self, obj):
return "Foo id: %i" % obj.pk

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I was looking for a solution for adding a writable custom field to a model serializer. I found this one, which has not been covered in the answers to this question.

看起来您确实需要编写自己的简单序列化程序。

class PassThroughSerializer(serializers.Field):
def to_representation(self, instance):
# This function is for the direction: Instance -> Dict
# If you only need this, use a ReadOnlyField, or SerializerField
return None


def to_internal_value(self, data):
# This function is for the direction: Dict -> Instance
# Here you can manipulate the data if you need to.
return data

现在可以使用此 Serializer 向 ModelSerializer 添加自定义字段

class MyModelSerializer(serializers.ModelSerializer)
my_custom_field = PassThroughSerializer()


def create(self, validated_data):
# now the key 'my_custom_field' is available in validated_data
...
return instance

如果 ModelMyModel实际上有一个名为 my_custom_field的属性，但是您想要忽略它的验证器，那么这也可以工作。

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在阅读了这里的所有答案之后，我的结论是不可能干净利落地做到这一点。您必须使用下流的方法，并执行一些新奇的操作，比如创建一个 write _ only 字段，然后覆盖 validate和 to_representation方法。这就是对我有效的方法:

class FooSerializer(ModelSerializer):


foo = CharField(write_only=True)


class Meta:
model = Foo
fields = ["foo", ...]


def validate(self, data):
foo = data.pop("foo", None)
# Do what you want with your value
return super().validate(data)


def to_representation(self, instance):
data = super().to_representation(instance)
data["foo"] = whatever_you_want
return data