Django 外键 rest 框架

Question

有没有办法在视图的“likedBy”部分显示用户名，而不是用户名？ 使用 django rest 框架从我得到的观点来看，忽略评论：

[
    {
        "id": 3,
        "title": "ddsa",
        "content": "dsadsa",
        "created": "2021-02-10T08:07:42.758400Z",
        "updated": "2021-02-10T08:07:42.758400Z",
        "author": 1,
        "category": [
            {
                "pk": 1,
                "name": "Life"
            }
        ],
        "likedBy": [
            1
        ],
        "comments": [
            {
                "id": 2,
                "content": "ghfa",
                "created": "2021-02-10T08:08:02.407950Z",
                "post": 3,
                "author": 1,
                "likedBy": [
                    1
                ]
            }
        ]
    }
]

视图.py：

class PostViewSet(FlexFieldsMixin, generics.ListAPIView):
    queryset = Post.objects.all()
    serializer_class = PostSerializer
    permit_list_expands = ['category', 'comments']

模型.py

class Post(models.Model):
    title = models.CharField(max_length=255)
    content = models.TextField()
    category = models.ManyToManyField(Category, related_name='posts')
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    created = models.DateTimeField(auto_now_add=True)
    updated = models.DateTimeField(auto_now=True)
    likedBy = models.ManyToManyField(User, related_name='posts', blank=True)

    class Meta:
        ordering = ['-created']

序列化器.py：

class PostSerializer(FlexFieldsModelSerializer):
    class Meta:
        model = Post
        fields = '__all__'
        expandable_fields = {
            'category': ('blogApi.CategorySerializer', {'many': True}),
            'comments': ('blogApi.CommentSerializer', {'many': True}),
        }

如何序列化 ManyToMany 字段以显示文本值

Answer 1

鉴于您没有序列化关系，而是与您的用户相关的 model 的属性，我相信您必须使用serializer.SerializerMethodField() 。 这允许您执行以下操作：

class PostSerializer(FlexFieldsModelSerializer):
    liked_by = serializers.SerializerMethodField(method_name="get_user_likes")

    class Meta:
        model = Post
        fields = (
            "title",
            "content",
            "category",
            "author",
            "created",
            "update",
            "liked_by"
        )
        expandable_fields = {
            'category': ('blogApi.CategorySerializer', {'many': True}),
            'comments': ('blogApi.CommentSerializer', {'many': True}),
        }

    @classmethod
    def get_user_likes(obj):
       # do whatever you like here, but I tend to call a 
       # method on my model to keep my serializer file
       # nice and tidy
       # you'll need to define a UserSerializer
       return UserSerializer(obj.get_user_likes(), many=True, read_only=True)

在您的帖子 model 中：

class Post(models.Model):
    title = models.CharField(max_length=255)
    content = models.TextField()
    category = models.ManyToManyField(Category, related_name='posts')
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    created = models.DateTimeField(auto_now_add=True)
    updated = models.DateTimeField(auto_now=True)
    likedBy = models.ManyToManyField(User, related_name='posts', blank=True)

    class Meta:
        ordering = ['-created']

    def get_user_likes(self):
        return self.likedBy.all()

您当然可以在序列化程序中定义完整的方法，但正如我所说，我希望序列化程序尽可能干净，并将与模型关联的所有方法放在我的 models.py 中。

    @classmethod
    def get_user_likes(obj):
       # you'll need to define a UserSerializer
       return UserSerializer(obj.likedBy.all(), many=True, read_only=True)

Answer 2

所以你可以设置

likedBy = serializers.ReadOnlyField(source='get_likedBy')

在您的 PostSerializer class 并在您的帖子 model ZA2F2ED4F8EBC04614C21A29D 中定义 function

@property
def get_likedBy(self):
   liked_by = []
   for user in self.users_liked_post.all():
       liked_by.append(user.name)
   return liked_by

只需使用正确的 related_name 而不是 users_liked_post

Answer 3

如果将 likedBy 添加到可扩展字段，然后将?expand=likedBy添加到 url，它应该会为您提供您在UserSerializer中概述的所有信息，或者编写一个名为LikedBySerializer的新序列化程序。 同样作为一般规则，尽量不要使用'__all__'这是泄漏数据的好方法。 快乐编码！

class LikedBySerializer(FlexFieldsModelSerializer):
    class Meta:
        model = User
        fields = '__all__'


class PostSerializer(FlexFieldsModelSerializer):
    class Meta:
        model = Post
        fields = '__all__'
        expandable_fields = {
            'category': ('blogApi.CategorySerializer', {'many': True}),
            'comments': ('blogApi.CommentSerializer', {'many': True}),
            'likedBy': ('blogApi.LikedBySerializer', {'many': True}),
        }