restframework详细

1.写视图的方法

1.1第一种：原始APIView

url(r'^login/$',account.LoginView.as_view()),

from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework_jwt.settings import api_settings
from rest_framework.throttling import AnonRateThrottle
from api import models

class LoginView(APIView):
    authentication_classes = []
    def post(self,request,*args,**kwargs):
        # 1.根据用户名和密码检测用户是否可以登录
        user = models.UserInfo.objects.filter(username=request.data.get('username'),password=request.data.get('password')).first()
        if not user:
            return Response({'code':10001,'error':'用户名或密码错误'})

        # 2. 根据user对象生成payload（中间值的数据）
        jwt_payload_handler = api_settings.JWT_PAYLOAD_HANDLER
        payload = jwt_payload_handler(user)

        # 3. 构造前面数据，base64加密；中间数据base64加密；前两段拼接然后做hs256加密（加盐），再做base64加密。生成token
        jwt_encode_handler = api_settings.JWT_ENCODE_HANDLER
        token = jwt_encode_handler(payload)
        return Response({'code': 10000, 'data': token})

1.2第二种：ListApiView等

url(r'^article/$',article.ArticleView.as_view()),
url(r'^article/(?P<pk>\d+)/$',article.ArticleDetailView.as_view()),

from rest_framework.throttling import AnonRateThrottle
from rest_framework.response import Response
from rest_framework.generics import ListAPIView,RetrieveAPIView
from api import models
from api.serializer.article import ArticleSerializer,ArticleDetailSerializer

class ArticleView(ListAPIView):
    authentication_classes = []
    # throttle_classes = [AnonRateThrottle,]

    queryset = models.Article.objects.all()
    serializer_class = ArticleSerializer

class ArticleDetailView(RetrieveAPIView):
    authentication_classes = []
    queryset = models.Article.objects.all()
    serializer_class = ArticleDetailSerializer

1.3第三种：

url(r'^article/$',article.ArticleView.as_view({"get":'list','post':'create'})),
    url(r'^article/(?P<pk>\d+)/$',article.ArticleView.as_view({'get':'retrieve','put':'update','patch':'partial_update','delete':'destroy'}))

from rest_framework.viewsets import GenericViewSet
from rest_framework.mixins import ListModelMixin,RetrieveModelMixin,CreateModelMixin,UpdateModelMixin,DestroyModelMixin
from api.serializer.article import ArticleSerializer,ArticleDetailSerializer

class ArticleView(GenericViewSet,ListModelMixin,RetrieveModelMixin,CreateModelMixin,UpdateModelMixin,DestroyModelMixin):
    authentication_classes = []
    throttle_classes = [AnonRateThrottle,]

    queryset = models.Article.objects.all()
    serializer_class = None

    def get_serializer_class(self):
        pk = self.kwargs.get('pk')
        if pk:
            return ArticleDetailSerializer
        return ArticleSerializer

2.drf 相关知识点梳理

2.1装饰器

def outer(func):
    def inner(*args,**kwargs):
        return func(*args,**kwargs)
    return inner

@outer
def index(a1):
    pass

index()

def outer(func):
    def inner(*args,**kwargs):
        return func(*args,**kwargs)
    return inner

def index(a1):
    pass

index = outer(index)

index()

2.2django中可以免除csrftoken认证

from django.views.decorators.csrf import csrf_exempt
from django.shortcuts import HttpResponse

@csrf_exempt
def index(request):
    return HttpResponse('...')

# index = csrf_exempt(index)

urlpatterns = [
    url(r'^index/$',index),
]

urlpatterns = [
    url(r'^login/$',account.LoginView.as_view()),
]

class APIView(View):
    @classmethod
    def as_view(cls, **initkwargs):
        view = super().as_view(**initkwargs)
        view.cls = cls
        view.initkwargs = initkwargs

        # Note: session based authentication is explicitly CSRF validated,
        # all other authentication is CSRF exempt.
        return csrf_exempt(view)

2.3面向对象中基于继承+异常处理来做的约束

class BaseVersioning:
    def determine_version(self, request, *args, **kwargs):
        raise NotImplementedError("must be implemented")

class URLPathVersioning(BaseVersioning):
	def determine_version(self, request, *args, **kwargs):
        version = kwargs.get(self.version_param, self.default_version)
        if version is None:
            version = self.default_version

        if not self.is_allowed_version(version):
            raise exceptions.NotFound(self.invalid_version_message)
        return version

2.4面向对象封装

class Foo(object):
	def __init__(self,name,age):
		self.name = name
		self.age = age 

obj = Foo('汪洋',18)

class APIView(View):
    def dispatch(self, request, *args, **kwargs):

        self.args = args
        self.kwargs = kwargs
        request = self.initialize_request(request, *args, **kwargs)
        self.request = request
		...

	def initialize_request(self, request, *args, **kwargs):
        """
        Returns the initial request object.
        """
        parser_context = self.get_parser_context(request)

        return Request( # 给request再封装一层
            request,
            parsers=self.get_parsers(),
            authenticators=self.get_authenticators(), # [MyAuthentication(),]
            negotiator=self.get_content_negotiator(),
            parser_context=parser_context
        )

2.5面向对象继承

class View(object):
   	pass

class APIView(View):
    def dispatch(self):
        method = getattr(self,'get')
        method()

class GenericAPIView(APIView):
    serilizer_class = None

    def get_seriliser_class(self):
        return self.serilizer_class

class ListModelMixin(object):
    def get(self):
        ser_class = self.get_seriliser_class()
        print(ser_class)

class ListAPIView(ListModelMixin,GenericAPIView):
    pass

class UserInfoView(ListAPIView):
    pass

view = UserInfoView()
view.dispatch()

class View(object):
   	pass

class APIView(View):
    def dispatch(self):
        method = getattr(self,'get')
        method()

class GenericAPIView(APIView):
    serilizer_class = None

    def get_seriliser_class(self):
        return self.serilizer_class

class ListModelMixin(object):
    def get(self):
        ser_class = self.get_seriliser_class()
        print(ser_class)

class ListAPIView(ListModelMixin,GenericAPIView):
    pass

class UserInfoView(ListAPIView):
    serilizer_class = "汪洋"

view = UserInfoView()
view.dispatch()

class View(object):
   	pass

class APIView(View):
    def dispatch(self):
        method = getattr(self,'get')
        method()

class GenericAPIView(APIView):
    serilizer_class = None

    def get_seriliser_class(self):
        return self.serilizer_class

class ListModelMixin(object):
    def get(self):
        ser_class = self.get_seriliser_class()
        print(ser_class)

class ListAPIView(ListModelMixin,GenericAPIView):
    pass

class UserInfoView(ListAPIView):

    def get_seriliser_class(self):
        return "咩咩"

view = UserInfoView()
view.dispatch()

2.6反射

class View(object):
	def dispatch(self, request, *args, **kwargs):
        # Try to dispatch to the right method; if a method doesn't exist,
        # defer to the error handler. Also defer to the error handler if the
        # request method isn't on the approved list.
        if request.method.lower() in self.http_method_names:
            handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
        else:
            handler = self.http_method_not_allowed
        return handler(request, *args, **kwargs)

2.7发送ajax请求

$.ajax({
	url:'地址',
	type:'GET',
	data:{...},
	success:function(arg){
		console.log(arg);
	}
})

• 简单请求，发送一次请求。
• 复杂请求，先options请求做预检，然后再发送真正请求

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>常鑫的网站</h1>
    <p>
        <input type="button" value="点我" onclick="sendMsg()">
    </p>
    <p>
        <input type="button" value="点他" onclick="sendRemoteMsg()">
    </p>

    <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
    <script>
        function sendMsg() {
            $.ajax({
                url:'/msg/',
                type:'GET',
                success:function (arg) {
                    console.log(arg);
                }
            })
        }
        function sendRemoteMsg() {
            $.ajax({
                url:'http://127.0.0.1:8002/json/',
                type:'GET',
                success:function (arg) {
                    console.log(arg);
                }
            })

        }
    </script>
</body>
</html>

2.8如何解决ajax+跨域？

CORS，跨站资源共享，本质：设置响应头。

2.9常见的Http请求方法

get
post
put
patch
delete
options

2.10http请求中Content-type请起头

情况一：
    content-type:x-www-form-urlencode
    name=alex&age=19&xx=10

	request.POST和request.body中均有值。

情况二：
	content-type:application/json
    {"name":"ALex","Age":19}

    request.POST没值
    request.body有值。

2.11django中F查询

2.12django中获取空Queryset

models.User.object.all().none()

2.13基于django的fbv和cbv都能实现遵循restful规范的接口

def user(request):
    if request.metho == 'GET':
        pass

class UserView(View):
    def get()...

    def post...

2.14基于django rest framework框架实现restful api的开发。

- 免除csrf认证
- 视图（APIView、ListAPIView、ListModelMinx）
- 版本
- 认证
- 权限
- 节流
- 解析器
- 筛选器
- 分页
- 序列化
- 渲染器

2.15简述drf中认证流程？

2.16简述drf中节流的实现原理以及过程？匿名用户/非匿名用户 如何实现频率限制？

2.17GenericAPIView视图类的作用？

他提供了一些规则，例如：

class GenericAPIView(APIView):
    serializer_class = None
    queryset = None
    lookup_field = 'pk'

    filter_backends = api_settings.DEFAULT_FILTER_BACKENDS
    pagination_class = api_settings.DEFAULT_PAGINATION_CLASS

    def get_queryset(self):
        return self.queryset

    def get_serializer_class(self):
        return self.serializer_class

	def filter_queryset(self, queryset):
        for backend in list(self.filter_backends):
            queryset = backend().filter_queryset(self.request, queryset, self)
        return queryset

    @property
    def paginator(self):
        if not hasattr(self, '_paginator'):
            if self.pagination_class is None:
                self._paginator = None
            else:
                self._paginator = self.pagination_class()
        return self._paginator

他相当于提供了一些规则，建议子类中使用固定的方式获取数据，例如：
class ArticleView(GenericAPIView):
    queryset = models.User.objects.all()

    def get(self,request,*args,**kwargs):
        query = self.get_queryset()

我们可以自己继承GenericAPIView来实现具体操作，但是一般不会，因为更加麻烦。
而GenericAPIView主要是提供给drf内部的 ListAPIView、Create....
class ListModelMixin:
    def list(self, request, *args, **kwargs):
        queryset = self.filter_queryset(self.get_queryset())

        page = self.paginate_queryset(queryset)
        if page is not None:
            serializer = self.get_serializer(page, many=True)
            return self.get_paginated_response(serializer.data)

        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)

class ListAPIView(mixins.ListModelMixin,GenericAPIView):
    def get(self, request, *args, **kwargs):
        return self.list(request, *args, **kwargs)

class MyView(ListAPIView):
    queryset = xxxx
    ser...

总结：GenericAPIView主要为drf内部帮助我们提供增删改查的类LIstAPIView、CreateAPIView、UpdateAPIView、提供了执行流程和功能，我们在使用drf内置类做CURD时，就可以通过自定义 静态字段（类变量）或重写方法（get_queryset、get_serializer_class）来进行更高级的定制。

2.18jwt以及其优势。

2.19序列化时many=True和many=False的区别？

2.20应用DRF中的功能进行项目开发

*****
	解析器:request.query_parmas/request.data
	视图
	序列化
	渲染器：Response

****
	request对象封装
	版本处理
	分页处理
***
	认证
	权限
	节流

• 基于APIView实现呼啦圈
• 继承ListAPIView+ GenericViewSet,ListModelMixin实现呼啦圈