标签：多个 closed patch header prope elf cti 而且 rtu
在学习django restful framework之前我们要先回顾一下：
1. 开发模式
- 普通开发方式（之前我们在开发的时候前后端放在一起写，也就是说一个人会负责前端和后端的代码，这样就会导致开发的效率较低，而且如果后端开发人员的前端基础较差的话，就会导致产品的质量不是很好）
- 前后端分离(前端人员做前端，VUE，后端的人员写后端的代码，因为很多的时候通过vue都是通过json数据进行传输的，因此作为后端的人员只需要将自己的数据通过json序列化之后就可以了)
2. 后端开发
为前端提供URL（API/接口的开发）
注：永远返回HttpResponse(通过json的形式)
3. Django FBV、CBV FBV,function base view def users(request): user_list = [‘alex‘,‘oldboy‘] return HttpResponse(json.dumps((user_list))) CBV,class base view 路由： url(r‘^students/‘, views.StudentsView.as_view()), 视图： from django.views import View class StudentsView(View): def get(self,request,*args,**kwargs): return HttpResponse(‘GET‘) def post(self, request, *args, **kwargs): return HttpResponse(‘POST‘) def put(self, request, *args, **kwargs): return HttpResponse(‘PUT‘) def delete(self, request, *args, **kwargs): return HttpResponse(‘DELETE‘)
ps：学会使用postman来模拟post请求
4. 列表生成式
class Foo:
pass
class Bar:
pass
v = []
for i in [Foo,Bar]:# 循环每个类
obj = i()# 类加括号实例化
v.append(obj)# 因此v里面就会有两个类的实例化对象
v = [item() for item in [Foo,Bar]] # 列表生成式
v其实就是一个对象列表
5. 面向对象基础知识
- 封装 - 对同一类方法封装到类中 class File: 文件增删改查方法 Class DB: 数据库的方法 - 将数据封装到对象中 class File: def __init__(self,a1,a2): self.a1 = a1 self.xxx = a2 def get:... def delete:... def update:... def add:... obj1 = File(123,666) obj2 = File(456,999) PS: 扩展 class Request(object): def __init__(self,obj): self.obj = obj @property def user(self): return self.obj.authticate() class Auth(object): def __init__(self,name,age): self.name = name self.age = age def authticate(self): return self.name class APIView(object): def dispatch(self): self.f2() def f2(self): a = Auth(‘alex‘,18) b = Auth(‘oldboy‘,18) req = Request(b) print(req.user) obj = APIView() obj.dispatch()
6.CVB形式的源码分析
1.因为每个url对应的都是一个函数，也就是一个视图当代码运行到url(r‘^students/‘, views.StudentsView.as_view())这里的时候其实就是返回一个视图，通过as_view->view返回一个视图函数 2.def as_view(cls, **initkwargs)-->def view(request, *args, **kwargs);当执行self = cls(**initkwargs)这句话的时候，cls加括号也就是实例化这个类，等价于：self = StudentsView() 3.下面就会执行return self.dispatch(request, *args, **kwargs)中的dispatch方法；换个方式：ret = self.dispatch(request, *args, **kwargs)，return ret 也就是执行StudentsView里面的dispatch方法；执行dispatch是有返回值的，返回的值就是Httpresponse以及render，redreit等等；换句话说也就是请求进来之后直接执行dispatch，无论是什么请求进来都会执行dispatch def dispatch(self, request, *args, **kwargs): func = getattr(self, request.method.lower()) #通过反射拿到请求方式然后转成小写 ret = func(request, *args, **kwargs)# 执行函数 return ret 4.在源码中如何实现的呢？ def dispatch(self, request, *args, **kwargs): 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)
FBV、CBV笔记说明：
CBV，基于反射实现根据请求方式不同，执行不同的方法。
原理：
url -> view方法 -> dispatch方法（反射执行其他：GET/POST/DELETE/PUT）
如果这样写呢？执行父类的方法
流程： class StudentsView(View): def dispatch(self, request, *args, **kwargs): print(‘before‘) ret = super(StudentsView,self).dispatch(request, *args, **kwargs) print(‘after‘) return ret def get(self,request,*args,**kwargs): return HttpResponse(‘GET‘) def post(self, request, *args, **kwargs): return HttpResponse(‘POST‘) def put(self, request, *args, **kwargs): return HttpResponse(‘PUT‘) def delete(self, request, *args, **kwargs): return HttpResponse(‘DELETE‘)
流程：
1.请求一进来先执行dispatch方法，然后执行父类的dispatch方法
2.里面的self指的是StudentsView，然后父类里面的handler = getattr(self, request.method.lower(), self.http_method_not_allowed)的self也是StudentsView，最后返回Httpresponse对象，然后将ret返回
继承：
1 继承（多个类共用的功能，为了避免重复编写）： 2 from django.views import View 3 4 5 class MyBaseView(object): 6 def dispatch(self, request, *args, **kwargs): 7 print(‘before‘) 8 ret = super(MyBaseView,self).dispatch(request, *args, **kwargs) 9 print(‘after‘) 10 return ret 11 12 class StudentsView(MyBaseView,View): 13 14 def get(self,request,*args,**kwargs): 15 print(‘get方法‘) 16 return HttpResponse(‘GET‘) 17 18 def post(self, request, *args, **kwargs): 19 return HttpResponse(‘POST‘) 20 21 def put(self, request, *args, **kwargs): 22 return HttpResponse(‘PUT‘) 23 24 def delete(self, request, *args, **kwargs): 25 return HttpResponse(‘DELETE‘) 26 27 class TeachersView(MyBaseView,View): 28 29 def get(self,request,*args,**kwargs): 30 return HttpResponse(‘GET‘) 31 32 def post(self, request, *args, **kwargs): 33 return HttpResponse(‘POST‘) 34 35 def put(self, request, *args, **kwargs): 36 return HttpResponse(‘PUT‘) 37 38 def delete(self, request, *args, **kwargs): 39 return HttpResponse(‘DELETE‘)
7.csrf补充
7.1. django中间件
- process_request
- process_view
- process_response
- process_exception
- process_render_template
当请求到来的时候，先是执行process_request，然后再执行process_view，再进入视图函数
7.2. 使用中间件做过什么？
- 权限
- 用户登录验证
- django的csrf是如何实现？
是放在process_view方法里面的：
如果加上from django.views.decorators.csrf import csrf_exempt，csrf_exempt免除csrf验证
- 检查视图是否被 @csrf_exempt （免除csrf认证）
- 去请求体或cookie中获取token
7.3：FBV
情况一： MIDDLEWARE = [ ‘django.middleware.security.SecurityMiddleware‘, ‘django.contrib.sessions.middleware.SessionMiddleware‘, ‘django.middleware.common.CommonMiddleware‘, ‘django.middleware.csrf.CsrfViewMiddleware‘, # 全站使用csrf认证 ‘django.contrib.auth.middleware.AuthenticationMiddleware‘, ‘django.contrib.messages.middleware.MessageMiddleware‘, ‘django.middleware.clickjacking.XFrameOptionsMiddleware‘, ] from django.views.decorators.csrf import csrf_exempt @csrf_exempt # 该函数无需认证 def users(request): user_list = [‘alex‘,‘oldboy‘] return HttpResponse(json.dumps((user_list))) 情况二： MIDDLEWARE = [ ‘django.middleware.security.SecurityMiddleware‘, ‘django.contrib.sessions.middleware.SessionMiddleware‘, ‘django.middleware.common.CommonMiddleware‘, #‘django.middleware.csrf.CsrfViewMiddleware‘, # 全站不使用csrf认证 ‘django.contrib.auth.middleware.AuthenticationMiddleware‘, ‘django.contrib.messages.middleware.MessageMiddleware‘, ‘django.middleware.clickjacking.XFrameOptionsMiddleware‘, ] from django.views.decorators.csrf import csrf_exempt @csrf_protect # 该函数需认证 def users(request): user_list = [‘alex‘,‘oldboy‘] return HttpResponse(json.dumps((user_list)))
7.4：CBV
CBV小知识,csrf时需要使用
- @method_decorator(csrf_exempt)
- 在dispatch方法中（单独方法无效）
方式一： from django.views.decorators.csrf import csrf_exempt,csrf_protect from django.utils.decorators import method_decorator class StudentsView(View): @method_decorator(csrf_exempt) def dispatch(self, request, *args, **kwargs): return super(StudentsView,self).dispatch(request, *args, **kwargs) def get(self,request,*args,**kwargs): print(‘get方法‘) return HttpResponse(‘GET‘) def post(self, request, *args, **kwargs): return HttpResponse(‘POST‘) def put(self, request, *args, **kwargs): return HttpResponse(‘PUT‘) def delete(self, request, *args, **kwargs): return HttpResponse(‘DELETE‘) 方式二： from django.views.decorators.csrf import csrf_exempt,csrf_protect from django.utils.decorators import method_decorator @method_decorator(csrf_exempt,name=‘dispatch‘) class StudentsView(View): def get(self,request,*args,**kwargs): print(‘get方法‘) return HttpResponse(‘GET‘) def post(self, request, *args, **kwargs): return HttpResponse(‘POST‘) def put(self, request, *args, **kwargs): return HttpResponse(‘PUT‘) def delete(self, request, *args, **kwargs): return HttpResponse(‘DELETE‘)
8.restful 规范（建议）
a. 接口开发 urlpatterns = [ # url(r‘^admin/‘, admin.site.urls), url(r‘^get_order/‘, views.get_order), url(r‘^add_order/‘, views.add_order), url(r‘^del_order/‘, views.del_order), url(r‘^update_order/‘, views.update_order), ] def get_order(request): return HttpResponse(‘‘) def add_order(request): return HttpResponse(‘‘) def del_order(request): return HttpResponse(‘‘) def update_order(request): return HttpResponse(‘‘)
这样就会出现一个小问题，url会越来越多，不好维护
b. restful 规范（建议） 1. 根据method不同做不同的操作，示例： 基于FBV: urlpatterns = [ url(r‘^order/‘, views.order), ] def order(request): if request.method == ‘GET‘: return HttpResponse(‘获取订单‘) elif request.method == ‘POST‘: return HttpResponse(‘创建订单‘) elif request.method == ‘PUT‘: return HttpResponse(‘更新订单‘) elif request.method == ‘DELETE‘: return HttpResponse(‘删除订单‘) 基于CBV: urlpatterns = [ url(r‘^order/‘, views.OrderView.as_view()), ] class OrderView(View): def get(self,request,*args,**kwargs): return HttpResponse(‘获取订单‘) def post(self,request,*args,**kwargs): return HttpResponse(‘创建订单‘) def put(self,request,*args,**kwargs): return HttpResponse(‘更新订单‘) def delete(self,request,*args,**kwargs): return HttpResponse(‘删除订单‘)
get:获取；delete：删除；post：创建；put：更新
9.安装：django rest framework框架
源码分析：cbv
1.当请求进来的时候首先会通过url对应一个函数，对于cbv的方式先会调用按时as_view，再去调用view方法返回对应的视图函数，最重要的是里面的dispatch方法
2.
def dispatch(self, request, *args, **kwargs): """ `.dispatch()` is pretty much the same as Django‘s regular dispatch, but with extra hooks for startup, finalize, and exception handling. """ self.args = args self.kwargs = kwargs request = self.initialize_request(request, *args, **kwargs) self.request = request self.headers = self.default_response_headers # deprecate? try: self.initial(request, *args, **kwargs) # Get the appropriate handler method 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 response = handler(request, *args, **kwargs) except Exception as exc: response = self.handle_exception(exc) self.response = self.finalize_response(request, response, *args, **kwargs) return self.response
在这个方法中首先request = self.initialize_request(request, *args, **kwargs)，在initialize_request这个方法中封装了一个Request
return Request( request, parsers=self.get_parsers(), authenticators=self.get_authenticators(), negotiator=self.get_content_negotiator(), parser_context=parser_context )
这里面的request是原生的request，里面的authenticators返回的是一个对象列表：接下来我们进入get_authenticators()这个方法中去：return [auth() for auth in self.authentication_classes]，返回的是一个列表生成式，也就是认证类的对象
因此执行了request = self.initialize_request(request, *args, **kwargs)这句话之后，那么这个request是一个全新的request，丰富了原生的request的内容
接下来就会执行self.initial(request, *args, **kwargs)这个方法，再去执行self.perform_authentication(request)这个方法，将新的request放入这个方法去处理：返回的是request.user
我们再看user里面是做了些什么：
def _authenticate(self): """ Attempt to authenticate the request using each authentication instance in turn. """ for authenticator in self.authenticators: try: user_auth_tuple = authenticator.authenticate(self) except exceptions.APIException: self._not_authenticated() raise if user_auth_tuple is not None: self._authenticator = authenticator self.user, self.auth = user_auth_tuple return self._not_authenticated()
通过for authenticator in self.authenticators:这个循环取到认证类的对象，然后一个个的认证，最后返回一个request.user
代码示例：
1 - 仅使用： 2 from django.views import View 3 from rest_framework.views import APIView 4 from rest_framework.authentication import BasicAuthentication 5 from rest_framework import exceptions 6 from rest_framework.request import Request 7 8 class MyAuthentication(object): 9 def authenticate(self,request): 10 token = request._request.GET.get(‘token‘) 11 # 获取用户名和密码，去数据校验 12 if not token: 13 raise exceptions.AuthenticationFailed(‘用户认证失败‘) 14 return ("alex",None) 15 16 def authenticate_header(self,val): 17 pass 18 19 class DogView(APIView): 20 authentication_classes = [MyAuthentication,] 21 22 def get(self,request,*args,**kwargs): 23 print(request) 24 print(request.user) 25 ret = { 26 ‘code‘:1000, 27 ‘msg‘:‘xxx‘ 28 } 29 return HttpResponse(json.dumps(ret),status=201) 30 31 def post(self,request,*args,**kwargs): 32 return HttpResponse(‘创建Dog‘) 33 34 def put(self,request,*args,**kwargs): 35 return HttpResponse(‘更新Dog‘) 36 37 def delete(self,request,*args,**kwargs): 38 return HttpResponse(‘删除Dog‘)
django学习之django restful framework(一)
标签：多个 closed patch header prope elf cti 而且 rtu
原文地址：https://www.cnblogs.com/chenjunkan/p/10026212.html
