1

我正在使用 Django REST API 和generic_relations模块来创建 Django Comments 的一种变体，它不是由模板驱动，而是通过 REST API 函数。

名为 Annotation 的 Model 类如下所示：

class Annotation(BaseCommentAbstractModel):

    paragraph_id = models.PositiveIntegerField(null=False)

    body = models.TextField()
    '''
    Annotations can be written only by logged in users. It is to prevent hit and run comments by people under anonymity.
    '''
    user = models.ForeignKey(DjangoUser, null=False, verbose_name=_('user'), related_name = "annotations")

现在，还有另一种模型，用于内容，几乎可以是任何东西，所以可以说，它是一个简单的发布应用程序：

class BlogContent(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    title = models.CharField(max_length=100, blank=True, default='')
    body = models.TextField()
    ...
    annotation = GenericRelation(Annotation, content_type_field='content_type', object_id_field='object_pk')

相同的序列化程序如下所示：

from generic_relations.relations import GenericRelatedField 

class BlogContentSerializer(serializers.ModelSerializer):
    author_id = serializers.Field(source='author_id.username')
    annotation = serializers.RelatedField(many=True)

    class Meta:
        model = BlogContent
        fields = ('title','created','author_id',
              'data','published_flag', 'url_path','slug','annotation')

class AnnotationSerializer(serializers.ModelSerializer):
    user = serializers.Field(source='user.username')
    content_object = GenericRelatedField({
        BlogContent: serializers.HyperlinkedRelatedField(view_name='annotation:blogcontent-detail'),
        }, read_only=False)

    class Meta:
        model = Annotation
        fields = ('paragraph_id', 'body', 'user', 'content_object')


class UserSerializer(serializers.ModelSerializer):
    blogcontent= serializers.PrimaryKeyRelatedField(many=True) 
    annotations = serializers.PrimaryKeyRelatedField(many=True)

    class Meta:
        model = User
        fields = ('username', 'id', 'blogcontent', 'annotations')

现在，问题出在这一行： content_object = GenericRelatedField({ BlogContent: serializers.HyperlinkedRelatedField(view_name='annotation:blogcontent-detail'), }, read_only=False)

如果泛型关系被用作只读，通过设置read_only=True，那么 REST API 可浏览性很好，但是当我将它切换到False时，服务器会返回一个 ValidationError

ValidationError at /en/annotation/
[u'Invalid model - model not available.']

仔细阅读日志和代码，似乎在rest_framework.renderers.pyatget_raw_data_form(self, view, method, request)调用中找不到对象obj = getattr(view, 'object', None)。

这反过来，在评估field_to_native函数 as serializer = self.determine_deserializer_for_data(value)in 时generic_relations，会导致 as 不传递任何内容，value因此代码中断。

有没有其他人也遇到过这样的错误和/或可以帮助我修复它？请帮忙！

回溯如下：

/home/craft/pirateenv/lib/python2.7/site-packages/django/core/handlers/base.py in get_response
            response = response.render() ...
▶ Local vars
/home/craft/pirateenv/lib/python2.7/site-packages/django/template/response.py in render
        self.content = self.rendered_content ...
▶ Local vars
/home/craft/pirateenv/lib/python2.7/site-packages/rest_framework/response.py in rendered_content
    ret = renderer.render(self.data, media_type, context) ...
▶ Local vars
/home/craft/pirateenv/lib/python2.7/site-packages/rest_framework/renderers.py in render
    context = self.get_context(data, accepted_media_type, renderer_context) ...
▶ Local vars
/home/craft/pirateenv/lib/python2.7/site-packages/rest_framework/renderers.py in get_context
    raw_data_post_form = self.get_raw_data_form(view, 'POST', request) ...
▶ Local vars
/home/craft/pirateenv/lib/python2.7/site-packages/rest_framework/renderers.py in get_raw_data_form
            content = renderer.render(serializer.data, accepted, context) ...
▶ Local vars
/home/craft/pirateenv/lib/python2.7/site-packages/rest_framework/serializers.py in data
            self._data = self.to_native(obj) ...
▶ Local vars
/home/craft/pirateenv/lib/python2.7/site-packages/rest_framework/serializers.py in to_native
        value = field.field_to_native(obj, field_name) ...
▶ Local vars
/home/craft/pirateenv/lib/python2.7/site-packages/generic_relations/relations.py in field_to_native
    serializer = self.determine_deserializer_for_data(value) ...
▶ Local vars
/home/craft/pirateenv/lib/python2.7/site-packages/generic_relations/relations.py in determine_deserializer_for_data
        raise ValidationError(self.error_messages['no_model_match']) ...
▶ Local vars
4

1 回答 1

0

存储库上的这个问题也提到了相同的错误，但在不同的上下文中，提供的解决方案仍然适用于我，直到作者发布修复程序。

if value:解决方法是在调用方法后添加一个 子句super。

于 2014-07-28T15:30:46.893 回答