DjangoRESTFrameWork中的视图

DRF中的request

在Django REST Framework中内置的Request类扩展了Django中的Request类，实现了很多方便的功能--如请求数据解析和认证等。

比如，区别于Django中的request从request.GET中获取URL参数，从request.POST中取某些情况下的POST数据。

在APIView中封装的request，就实现了请求数据的解析：

对于GET请求的参数我们通过request.query_params来获取。

对于POST请求、PUT请求的数据我们通过request.data来获取。

视图的使用:

1 前提之序列化

# 首先需要在setting中注册rest_framework的中间件

from rest_framework import serializers
from crm import models


class PublisherModel(serializers.ModelSerializer):
    class Meta:
        model =models.Publisher
        fields = '__all__'


class AuthorModel(serializers.ModelSerializer):
    class Meta:
        model = models.Author
        fields = '__all__'


class BookSerializers(serializers.Serializer):
    id = serializers.IntegerField(required=False)
    name = serializers.CharField(max_length=32)
    pub_date = serializers.DateField()

    CHOICES = ((1, 'python'), (2, 'go语言'), (3, 'linux'))
    # source设置数据读取时候读取到 CHOICES里面的内容,read_only设置只在读取时有效
    category = serializers.CharField(source='get_category_display',read_only=True)
    post_category = serializers.IntegerField(write_only=True)

    # 对出版社字段进行校验 读取时,和设置是显示的格式不同
    publisher = PublisherSerializers(read_only=True)
    post_publisher = serializers.IntegerField(write_only=True)

    # 对作者字段进行校验
    author = AuthorSerializers(many=True, read_only=True)
    post_author = serializers.ListField(write_only=True)

# create方法相当于对每个通过校验的字段进行获取在数据库中新建保存
    def create(self, validated_data):  # validated_data里面保存的是校验通过后的数据
        book_obj = models.Book.objects.create(
            name=validated_data["name"],
            pub_date=validated_data["pub_date"],
            category=validated_data["post_category"],
            publisher_id=validated_data["post_publisher"]
        )
        book_obj.author.set(validated_data["post_author"])  # 多对多字段需要重新设置关系
        return book_obj

    def update(self, instance, validated_data):
        # 从validated_data中取出数据挨个字段更新
        instance.name = validated_data.get('name', instance.name)
        instance.pub_date = validated_data.get('pub_date', instance.pub_date)
        instance.category = validated_data.get('post_category', instance.category)
        instance.publisher_id = validated_data.get('post_publisher', instance.publisher_id)
        instance.save()
        # 更新多对多字段的 authors
        # 先取出当前书籍的所有作者id
        author_list = instance.author.all().values_list('id')  # [(1,),(2,)] ==> [1, 2]

        instance.author.set(validated_data.get('post_authors', [i[0] for i in author_list]))
        return instance

serializers

2 初级阶段

from rest_framework.response import Response
from rest_framework.views import APIView

# 图书的展示以及添加
class Book(APIView):  # 继承改为restframework的封装的APIView
    def get(self, request):
        # 1,在后端获取数据
        book_obj = models.Book.objects.all()
        # 2,使用seriallizers进行数据格式化
        ser_obj = BookSerializers(book_obj, many=True)
        # 返回给前端  Response方法是serializers封装的方法
        return Response(ser_obj.data)

    def post(self, request):
        # 1, 在前端获取提交的数据
        # 此时的request已经是被serializers封装过的request,不是简单的页面提交的那个request
        # 前端提交的数据存在request.data里面 print(request.data)
        # 2, 进行serializers校验
        ser_obj = BookSerializers(data=request.data)
        if ser_obj.is_valid():  # 如果通过了校验
            print("oye")
            # 数据校验通过以后,想要使用save方法保存的话,需要调用BookSerializers里面的create方法
            ser_obj.save()
            return Response('数据添加成功!')
        else:  # 没通过校验的数据,返回错误信息
            print('ono')
            return Response(ser_obj.errors)

# 具体图书信息的展示以及修改和删除
class BookDetail(APIView):  

    def get(self, request, pk):
        book_obj = models.Book.objects.filter(pk=pk).first()
       
        if book_obj:
            ser_obj = BookModel(book_obj)  # 对数据进行有效性校验
            return Response(ser_obj.data)  
        else:
            return Response('无效的id')

    def put(self, request, pk):
        book_obj = models.Book.objects.filter(pk=pk).first()
        if book_obj:
            ser_obj = BookSerializers(instance=book_obj, data=request.data, partial=True)  # 此处得到request已经是封装过的,partial表示局部更新
            if ser_obj.is_valid():
                ser_obj.save()
                return Response(ser_obj.data)
            else:
                return Response(ser_obj.errors)
        else:
            return Response('无效的id')
    
    def delete(self,request,pk):
        book_obj = models.Book.objects.filter(pk=pk).first()
        if book_obj:
            book_obj.delete()
            return Response("删除成功")
        else:
            return Response("无效的id")

3 强化版

from django.contrib import admin
from django.urls import path,re_path
from crm import views
urlpatterns = [
    path('admin/', admin.site.urls),
    path('book/', views.Book.as_view()),
    re_path('book/(?P<pk>\d+)/$', views.BookDetail.as_view()),

    path('author/', views.Authorshow.as_view()),
    re_path('author/(?P<pk>\d+)/$', views.AuthorDetail.as_view()),


    path('publisher/', views.Publishershow.as_view()),
    re_path('publisher/(?P<pk>\d+)', views.PublisherDetail.as_view()),


]

路由

# 公共类,获取数据使用
class GerneridView(APIView):
    queryset = None
    serializer_class = None

    def get_queryset(self):
        queryset = self.queryset.all()  # 刷新数据
        return queryset

    def get_object(self, request, pk, *args, **kwargs):
        queryset = self.queryset.filter(pk=pk).first()
        return queryset


class ListMixin(object):
    def get(self, request):
        queryset = self.get_queryset()
        ser_obj = self.serializer_class(queryset, many=True)
        return Response(ser_obj.data)


class CreateMixin(object):
    def post(self, request):
        ser_obj = self.serializer_class(data=request.data)
        if ser_obj.is_valid():
            ser_obj.save()
            return Response('OK')
        else:
            return Response(ser_obj.errors)


class ActreveMixin(object):
    def get(self, request, pk, *args, **kwargs):
        obj = self.get_object(request, pk, *args, **kwargs)
        if obj:
            ser_obj = self.serializer_class(obj)
            return Response(ser_obj.data)
        else:
            return Response("无效的id")


class UpdateMixin(object):
    def put(self, request, pk, *args, **kwargs):
        book_obj = self.get_object(request, pk, *args, **kwargs)
        if book_obj:
            ser_obj = AuthorModel(instance=book_obj, data=request.data, partial=True)
            if ser_obj.is_valid():
                ser_obj.save()
                return Response("数据更新成功")
            else:
                return Response(ser_obj.errors)
        else:
            return Response("无效的id")


class DelMixin(object):
    def delete(self,request, pk, *args, **kwargs):
        obj = self.get_object(request, pk, *args, **kwargs)
        if obj:
            obj.delete()
            return Response('删除成功')
        else:
            return Response("无效的id")


class Authorshow(GerneridView, ListMixin, CreateMixin):
    queryset = models.Author.objects.all()
    serializer_class = AuthorModel


class AuthorDetail(GerneridView, ActreveMixin, UpdateMixin, DelMixin):
    queryset =models.Author.objects.all()
    serializer_class = AuthorModel

面向对象封装版

4 究极进化版

from django.urls import path,re_path
from bms import views
urlpatterns = [
    path('admin/', admin.site.urls),

    # 作者相关操作
    path('author/', views.AuthorShow.as_view(actions={'get': 'list', 'post': 'create'})),
    re_path('author/(?P<pk>\d+)/$', views.AuthorShow.as_view(actions={'get': 'retrieve', 'put': 'update', 'delete': 'destroy'})),

    # 出版社相关操作
    path('publisher/', views.PublisherShow.as_view(actions={'get': 'list', 'post': 'create'})),
    re_path('publisher/(?P<pk>\d+)/$', views.PublisherShow.as_view(actions={'get': 'retrieve', 'put': 'update', 'delete': 'destroy'})),

    # 图书相关增删改查操作
    path('books/', views.BooksShow.as_view(actions={'get': 'list', 'post': 'create'})),
    re_path('books/(?P<pk>\d+)/$', views.BooksShow.as_view(actions={'get': 'retrieve', 'put': 'update', 'delete': 'destroy'})),

]

路由

from bms import models
# Create your views here.
from rest_framework.viewsets import ModelViewSet
from bms.serializer import AuthorModel, PublisherModel, BookModel


class AuthorShow(ModelViewSet):
    queryset = models.Author.objects.all()
    serializer_class = AuthorModel


class PublisherShow(ModelViewSet):
    queryset = models.Publisher.objects.all()
    serializer_class = PublisherModel


class BooksShow(ModelViewSet):
    queryset = models.Book.objects.all()
    serializers = BookModel

究极进化版

5 无比强大的路由

from rest_framework.routers import DefaultRouter

router = DefaultRouter()
router.register(r'school', views.SchoolView)
urlpatterns += router.urls

6 一张不明觉厉的图