在django rest框架中按通用关系按名称设置内容类型

时间:2014-07-26 11:36:00

标签: python django django-rest-framework generic-relationship

class Foo(models.Model):
    bar = models.CharField(max_length=300)
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey('content_type', 'object_id')


class FooSerializer(serializers.ModelSerializer):
    class Meta:
       model = Foo

class FooViewSet(viewsets.ModelViewSet):
    model = Foo
    serializer_class = FooSerializer

我现在可以将数据发布到如下所示的视图集:

{
    bar: 'content',
    content_type: 1
    object_id: 5
}

唯一让我烦恼的是,前端必须知道内容类型ID

相反,我希望能够发布content_types名称,例如' User' as content_type并让后端确定id。

3 个答案:

答案 0 :(得分:8)

您可以自定义WritableField以将contenttype id映射到'app_label.model'字符串:

class ContentTypeField(serializers.WritableField):
    def field_from_native(self, data, files, field_name, into):
        into[field_name] = self.from_native(data[field_name])

    def from_native(self, data):
        app_label, model = data.split('.')
        return ContentType.objects.get(app_label=app_label, model=model)

    # If content_type is write_only, there is no need to have field_to_native here.
    def field_to_native(self, obj, field_name):
        if self.write_only:
            return None
        if obj is None:
            return self.empty
        ct = getattr(obj, field_name)
        return '.'.join(ct.natural_key())


class FooSerializer(serializers.ModelSerializer):
    content_type = ContentTypeField()
    # ...

您可能需要执行第二次映射以限制contenttype的选择并避免推出应用/型号名称:

CONTENT_TYPES = {
  'exposed-contenttype': 'app_label.model'
}

class ContentTypeField(...):
    def from_native(self, data):
        if data not in CONTENT_TYPES:
            raise serializers.ValidationError(...)
        app_label, model = CONTENT_TYPES[data].split('.')
        # ...

答案 1 :(得分:3)

DRF 3.x中用于读/写操作的最简单,最干净的方法:

from django.contrib.contenttypes.models import ContentType
from rest_framework import serializers
from .models import Foo

class FooSerializer(serializers.ModelSerializer):
    class Meta:
       model = Foo

    content_type = serializers.SlugRelatedField(
        queryset=ContentType.objects.all(),
        slug_field='model',
    )

然后,您可以使用型号名称执行CRUD操作:

data = {
    'bar': "content",
    'content_type': "model_name",
    'object_id': 1,
}

答案 2 :(得分:1)

DRF已经改变,现在有了新的方法 - to_internal_value和to_representation,而不是from_native和field_to_native。

现在更简单了:

class ContentTypeField(serializers.Field):

    def to_representation(self, obj):
        return obj.model

    def to_internal_value(self, data):
        return ContentType.objects.get(model=data)