Json 如何在 django rest 框架中定义列表字段

发布于07月29日

Let's say I have a class

class Tags(object):

    tags = []

    def __init__(self, tags):
        self.tags = tags

和一个自定义列表字段

class TagsField(serializers.WritableField):
    """
    Returns a list of tags, or serializes a list of tags
    """

我不太确定接下来该怎么办.如何确保博客帖子序列化器定义为

class BlogPostSerializer(serializers.Serializer):
    post = CharField()
    tags = TagsField

会给我一个类似于

{
    "post": "Here is my blog post about python",
    "tags": ["python", "django", "rest"]
}

推荐答案

One way to deal with arrays for a non ORM-based object is to override the to_native and from_native methods. In your case:

class TagsField(serializers.WritableField):

    def from_native(self, data):
        if isinstance(data, list):
            return Tags(data)
        else:
            msg = self.error_messages['invalid']
            raise ValidationError(msg)

    def to_native(self, obj):
        return obj.tags

If you had an ORM-based object you would like to look at the SlugRelatedField with the many = True attribute.

From Django Rest Framework version 3.0 you can also use ListField http://www.django-rest-framework.org/api-guide/fields/#listfield