# 請求對象
# from rest_framework.request import Request
    def __init__(self, request, parsers=None, authenticators=None,
                 negotiator=None, parser_context=None):
        # 二次封裝request，將原生request作為drf request對象的 _request 屬性
        self._request = request
    def __getattr__（self，item）：
     return getattr(self._request,item)
# 請求對象.data:前端以三種編碼方式傳入的數(shù)據(jù)，都可以取出來
# 請求對象..query_params 與Django標準的request.GET相同，只是更換了更正確的名稱而已。

#from rest_framework.response import Response
 def __init__(self, data=None, status=None,
                 template_name=None, headers=None,
                 exception=False, content_type=None):
        
#data：你要返回的數(shù)據(jù)，字典
#status：返回的狀態(tài)碼，默認是200，
 -from rest_framework import status在這個路徑下，它把所有使用到的狀態(tài)碼都定義成了常量
#template_name 渲染的模板名字（自定制模板），不需要了解
#headers:響應頭，可以往響應頭放東西，就是一個字典
#content_type：響應的編碼格式，application/json和text/html;

# 瀏覽器響應成瀏覽器的格式，postman響應成json格式，通過配置實現(xiàn)的（默認配置）
#不管是postman還是瀏覽器，都返回json格式數(shù)據(jù)
# drf有默認的配置文件---》先從項目的setting中找，找不到，采用默認的
# drf的配置信息，先從自己類中找--》項目的setting中找---》默認的找
 -局部使用:對某個視圖類有效
        -在視圖類中寫如下
        from rest_framework.renderers import JSONRenderer
        renderer_classes=[JSONRenderer,]
    -全局使用：全局的視圖類，所有請求，都有效
     -在setting.py中加入如下
        REST_FRAMEWORK = {
            'DEFAULT_RENDERER_CLASSES': (  # 默認響應渲染類
                'rest_framework.renderers.JSONRenderer',  # json渲染器
                'rest_framework.renderers.BrowsableAPIRenderer',  # 瀏覽API渲染器
            )
        }

# 兩個視圖基類
APIView
GenericAPIView

#### views.py
from rest_framework.generics import GenericAPIView
from app01.models import Book
from app01.ser import BookSerializer
# 基于APIView寫的
class BookView(APIView):
    def get(self,request):
        book_list=Book.objects.all()
        book_ser=BookSerializer(book_list,many=True)

        return Response(book_ser.data)
    def post(self,request):
        book_ser = BookSerializer(data=request.data)
        if book_ser.is_valid():
            book_ser.save()
            return Response(book_ser.data)
        else:
            return Response({'status':101,'msg':'校驗失敗'})


class BookDetailView(APIView):
    def get(self, request,pk):
        book = Book.objects.all().filter(pk=pk).first()
        book_ser = BookSerializer(book)
        return Response(book_ser.data)

    def put(self, request,pk):
        book = Book.objects.all().filter(pk=pk).first()
        book_ser = BookSerializer(instance=book,data=request.data)
        if book_ser.is_valid():
            book_ser.save()
            return Response(book_ser.data)
        else:
            return Response({'status': 101, 'msg': '校驗失敗'})

    def delete(self,request,pk):
        ret=Book.objects.filter(pk=pk).delete()
        return Response({'status': 100, 'msg': '刪除成功'})
    
#models.py
class Book(models.Model):
    name=models.CharField(max_length=32)
    price=models.DecimalField(max_digits=5,decimal_places=2)
    publish=models.CharField(max_length=32)
#ser.py
class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model=Book
        fields='__all__'
# urls.py
path('books/', views.BookView.as_view()),
re_path('books/(?P<pk>\d+)', views.BookDetailView.as_view()),

# views.py
class Book2View(GenericAPIView):
    #queryset要傳queryset對象，查詢了所有的圖書
    # serializer_class使用哪個序列化類來序列化這堆數(shù)據(jù)
    queryset=Book.objects
    # queryset=Book.objects.all()
    serializer_class = BookSerializer
    def get(self,request):
        book_list=self.get_queryset()
        book_ser=self.get_serializer(book_list,many=True)

        return Response(book_ser.data)
    def post(self,request):
        book_ser = self.get_serializer(data=request.data)
        if book_ser.is_valid():
            book_ser.save()
            return Response(book_ser.data)
        else:
            return Response({'status':101,'msg':'校驗失敗'})


class Book2DetailView(GenericAPIView):
    queryset = Book.objects
    serializer_class = BookSerializer
    def get(self, request,pk):
        book = self.get_object()
        book_ser = self.get_serializer(book)
        return Response(book_ser.data)

    def put(self, request,pk):
        book = self.get_object()
        book_ser = self.get_serializer(instance=book,data=request.data)
        if book_ser.is_valid():
            book_ser.save()
            return Response(book_ser.data)
        else:
            return Response({'status': 101, 'msg': '校驗失敗'})

    def delete(self,request,pk):
        ret=self.get_object().delete()
        return Response({'status': 100, 'msg': '刪除成功'})
    
 #url.py
    # 使用GenericAPIView重寫的
    path('books2/', views.Book2View.as_view()),
    re_path('books2/(?P<pk>\d+)', views.Book2DetailView.as_view()),

from rest_framework.mixins import  ListModelMixin,CreateModelMixin,UpdateModelMixin,DestroyModelMixin,RetrieveModelMixin
# views.py
class Book3View(GenericAPIView,ListModelMixin,CreateModelMixin):

    queryset=Book.objects
    serializer_class = BookSerializer
    def get(self,request):
        return self.list(request)

    def post(self,request):
        return self.create(request)

class Book3DetailView(GenericAPIView,RetrieveModelMixin,DestroyModelMixin,UpdateModelMixin):
    queryset = Book.objects
    serializer_class = BookSerializer
    def get(self, request,pk):
        return self.retrieve(request,pk)

    def put(self, request,pk):
        return self.update(request,pk)

    def delete(self,request,pk):
        return self.destroy(request,pk)
# urls.py
    # 使用GenericAPIView+5 個視圖擴展類  重寫的
    path('books3/', views.Book3View.as_view()),
    re_path('books3/(?P<pk>\d+)', views.Book3DetailView.as_view()),

# views.py
from rest_framework.viewsets import ModelViewSet
class Book5View(ModelViewSet):  #5個接口都有，但是路由有點問題
    queryset = Book.objects
    serializer_class = BookSerializer
    
# urls.py
# 使用ModelViewSet編寫5個接口
    path('books5/', views.Book5View.as_view(actions={'get':'list','post':'create'})), #當路徑匹配，又是get請求，會執(zhí)行Book5View的list方法
    re_path('books5/(?P<pk>\d+)', views.Book5View.as_view(actions={'get':'retrieve','put':'update','delete':'destroy'})),

# 重寫了as_view
# 核心代碼（所以路由中只要配置了對應關(guān)系，比如{'get':'list'}）,當get請求來，就會執(zhí)行l(wèi)ist方法
for method, action in actions.items():
    #method：get
    # action：list
    handler = getattr(self, action)
    #執(zhí)行完上一句，handler就變成了list的內(nèi)存地址
    setattr(self, method, handler)
    #執(zhí)行完上一句  對象.get=list
    #for循環(huán)執(zhí)行完畢 對象.get:對著list   對象.post：對著create

# views.py
from rest_framework.viewsets import ViewSetMixin
class Book6View(ViewSetMixin,APIView): #一定要放在APIVIew前
    def get_all_book(self,request):
        print("xxxx")
        book_list = Book.objects.all()
        book_ser = BookSerializer(book_list, many=True)
        return Response(book_ser.data)
    
# urls.py
    #繼承ViewSetMixin的視圖類，路由可以改寫成這樣
    path('books6/', views.Book6View.as_view(actions={'get': 'get_all_book'})),