django rest framework 解析器组件 接口设计,视图组件 (1)

一.解析器组件

-解析器组件是用来解析用户请求数据的（application/json), content-type 将客户端发来的json数据进行解析

-必须适应APIView

-request.data触发

二.序列化组件

2.1.django 自带组件serializer

2.1.1 from django.serializers import serialize
2.1.2 origin_data = Book.objects.all()
2.1.3 serialized_data = serialize("json", origin_data)

2.2 DRF的序列化组件
-get接口设计 本质上是基于解释器进行json数据解析的组件 接口就是url 存储的唯一资源


使用:

2.2.1 from rest_framework import serializers
2.2.2 创建一个序列化类
     class BookSerializer(serializers.Serializer):

         publish_name = serializers.CharField(read_only=True, source="publish.name")
         authors_list = serializers.SerializerMethodField()
         
         def get_authors_list(self, book_obj):
            pass
2.2.3 开始序列化
      origin_data = Book.objects.all()
      serialized_data = BookSerializer(origin_data, many=True)

      return Response(serialized_data.data)

- post接口设计
   总结：
      1. serializers.Serializer无法插入数据，只能自己实现create
      2. 字段太多，不能自动序列化
- get单条数据接口设计
   1. 定义url
   2. 获取数据对象
   3. 开始序列化：serialized_data = BookSerializer(book_obj, many=False)
   4. 返回数据：serialized_data.data
- delete
- put
   1. 定义url
   2. 获取数据对象
      2.1 book_obj = Book.objects.get(pk=1)
   3. 开始序列化（验证数据，save()）
      2.2 verified_data = BookSerializer(instance=book_obj, many=False)
   4. 验证成功写入数据库，验证失败返回错误
      4.1 verified_data.is_valid()

    #re_path(r'books/$', views.BookView.as_view()),
    #re_path(r'books/(?P<pk>d+)/$', views.BookFilterView.as_view()),

'''
class BookSerializer(serializers.Serializer):
    # 这里字段一定要与models的一致
    title = serializers.CharField(max_length=32)
    price = serializers.DecimalField(max_digits=5, decimal_places=2)
    #  一对多 具体告诉返回什么而不是对象,这里返回的是一个出版社的城市
    publish = serializers.CharField(max_length=32, source='publish.city')
    # 多对多 需要手动查找
    authors_list = serializers.SerializerMethodField()
    # get_ +  authors_list
    def get_authors_list(self, book_obj):
        author_list = list()
        # book_obj 是每一个书籍对象,通过和关联字段找到所有名字

        for author in book_obj.authors.all():
            author_list.append(author.name)
        #    最后通过get_ 返回
        return author_list
    #     自定义post 
    def create(self, book_obj):
        book_obj["publish_id"] = book_obj.pop("publish")
        book = Book.objects.create(**book_obj)
        return book
# 这样发现这个在字段多的表是
'''

#
# class BookView(APIView):
#     def get(self,request):
#         course_data=Book.objects.all()
#         book_data =BookSerializer(course_data,many=True)
#
#         return Response(book_data.data)
#     # 笨方法
#     def post(self,request):
#         verified_data = BookSerializer(data=request.data)
#         print("verified_data",verified_data)
#         if verified_data.is_valid():
#             book =verified_data.save()
#             print("request.data",request.data)
#             authors = Author.objects.filter(nid__in=request.data['author_list'])
#             print("authors",authors)
#             book.authors.add(*authors)
#             return Response(verified_data.data)
# class BookFilterView(APIView):
#     def get(self,request,nid):
#         book_obj = Book.objects.get(pk=nid)
#         serialized_data=BookSerializer(book_obj,many=False)
#         return Response(serialized_data.data)
#
#     def put(self,request,nid):
#         book_obj = Book.objects.get(pk=nid)
#         verified_data = BookSerializer(data=request.data,instance=book_obj)
#         if verified_data.is_valid():
#             verified_data.save()
#             return Response(verified_data.data)
#         else:
#             return Response(verified_data.errors)
#
#     def delete(self,request,nid):
#         book_obj = Book.objects.get(pk=nid).delete()
#         return Response()

但是发现,使用这种会十分累,于是进行优化

视图组件进行接口优化