一.解析器元件

-解析器元件是用來解析使用者請求資料的（application/json), content-type 將客戶端發來的json資料進行解析

-必須適應APIView

-request.data觸發

二.序列化元件

2.1.django 自帶元件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的序列化元件
-get介面設計 本質上是基於直譯器進行json資料解析的元件 介面就是url 儲存的唯一資源


使用:

2.2.1 from rest_framework import serializers
2.2.2 建立一個序列化類
     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 開始序列化
      origin_data = Book.objects.all()
      serialized_data = BookSerializer(origin_data, many=True)

      return Response(serialized_data.data)

- post介面設計
   總結：
      1. serializers.Serializer無法插入資料，只能自己實現create
      2. 欄位太多，不能自動序列化
- get單條資料介面設計
   1. 定義url
   2. 獲取資料物件
   3. 開始序列化：serialized_data = BookSerializer(book_obj, many=False)
   4. 返回資料：serialized_data.data
- delete
- put
   1. 定義url
   2. 獲取資料物件
      2.1 book_obj = Book.objects.get(pk=1)
   3. 開始序列化（驗證資料，save()）
      2.2 verified_data = BookSerializer(instance=book_obj, many=False)
   4. 驗證成功寫入資料庫，驗證失敗返回錯誤
      4.1 verified_data.is_valid()

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

 1 '''
 2 class BookSerializer(serializers.Serializer):
 3     # 這裡欄位一定要與models的一致
 4     title = serializers.CharField(max_length=32)
 
 5     price = serializers.DecimalField(max_digits=5, decimal_places=2)
 6     #  一對多 具體告訴返回什麼而不是物件,這裡返回的是一個出版社的城市
 7     publish = serializers.CharField(max_length=32, source='publish.city')
 8     # 多對多 需要手動查詢
 9     authors_list = serializers.SerializerMethodField()
10     # get_ +  authors_list
11     def get_authors_list(self, book_obj):
12         author_list = list()
13         # book_obj 是每一個書籍物件,通過和關聯欄位找到所有名字
14 
15         for author in book_obj.authors.all():
16             author_list.append(author.name)
17         #    最後通過get_ 返回
18         return author_list
19     #     自定義post 
20     def create(self, book_obj):
21         book_obj["publish_id"] = book_obj.pop("publish")
22         book = Book.objects.create(**book_obj)
23         return book
24 # 這樣發現這個在欄位多的表是
25 '''

 1 #
 2 # class BookView(APIView):
 3 #     def get(self,request):
 4 #         course_data=Book.objects.all()
 5 #         book_data =BookSerializer(course_data,many=True)
 6 #
 7 #         return Response(book_data.data)
 8 #     # 笨方法
 9 #     def post(self,request):
10 #         verified_data = BookSerializer(data=request.data)
11 #         print("verified_data",verified_data)
12 #         if verified_data.is_valid():
13 #             book =verified_data.save()
14 #             print("request.data",request.data)
15 #             authors = Author.objects.filter(nid__in=request.data['author_list'])
16 #             print("authors",authors)
17 #             book.authors.add(*authors)
18 #             return Response(verified_data.data)
19 # class BookFilterView(APIView):
20 #     def get(self,request,nid):
21 #         book_obj = Book.objects.get(pk=nid)
22 #         serialized_data=BookSerializer(book_obj,many=False)
23 #         return Response(serialized_data.data)
24 #
25 #     def put(self,request,nid):
26 #         book_obj = Book.objects.get(pk=nid)
27 #         verified_data = BookSerializer(data=request.data,instance=book_obj)
28 #         if verified_data.is_valid():
29 #             verified_data.save()
30 #             return Response(verified_data.data)
31 #         else:
32 #             return Response(verified_data.errors)
33 #
34 #     def delete(self,request,nid):
35 #         book_obj = Book.objects.get(pk=nid).delete()
36 #         return Response()

但是發現,使用這種會十分累,於是進行優化

檢視元件進行介面優化