Django rest framework（2）----权限

一 添加权限

（1）API/utils文件夹下新建premission.py文件，代码如下：

• message是当没有权限时，提示的信息

#!/usr/bin/env python
# coding:utf-8

from rest_framework.permissions import BasePermission

class SVIPPermission(BasePermission):
    message = "必须是SVIP才能访问，你权限太低，滚"
    def has_permission(self,request,view):
        # request.user 表示获取到 UserInfo 这个类的对象
        if request.user.user_type != 3:
            return False
        return True

class MyPermission(BasePermission):
    message = "没有权限查看我，滚"
    def has_permission(self,request,view):
        if request.user.user_type == 3:
            return False
        return True

　　

（2）settings.py全局配置权限

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': ['API.utils.auth.Authentication',],
    'DEFAULT_PERMISSION_CLASSES': ['API.utils.permission.SVIPPermission'],
}

　　

（3）views.py添加权限

• 默认所有的业务都需要SVIP权限才能访问
• OrderView类里面没写表示使用全局配置的SVIPPremission
• UserInfoView类，因为是普通用户和VIP用户可以访问，不使用全局的，要想局部使用的话，里面就写上自己的权限类
• permission_classes = [MyPremission,]   #局部使用权限方法

#!/usr/bin/env python
# coding:utf-8
from django.shortcuts import render,HttpResponse

from django.http import JsonResponse
from rest_framework.views import APIView
from API import models
from rest_framework.request import Request
from rest_framework import exceptions
from rest_framework.authentication import BasicAuthentication
from API.utils.permission import SVIPPermission,MyPermission


import hashlib
import time
def md5(user):
    ctime = str(time.time())
    m = hashlib.md5(user)
    m.update(ctime)
    return m.hexdigest()


class AuthView(APIView):
    authentication_classes = []
    permission_classes = []
    def post(self,request,*args,**kwargs):
        ret = {'code': 1000,'msg':None}
        try:
            user = request.POST.get('username')
            pwd = request.POST.get('password')
            print(user,pwd)
            obj = models.UserInfo.objects.filter(username=user,password=pwd).first()
            print('=============%s' %(obj))
            if not obj:
                ret['code'] = 1001
                ret['msg'] = '用户名或者密码错误'
            # 为用户创建token
            token = md5(user)
            # 存在就更新，不存在就创建
            models.UserToken.objects.update_or_create(user=obj,defaults={'token':token})
            ret['token'] = token
        except Exception as e:
            ret['code'] = 1002
            ret['msg'] = '请求异常'

        # user = request._request.POST.get('username')
        # pwd = request._request.POST.get('password')
        # print(user,pwd)
        # obj = models.UserInfo.objects.filter(username=user,password=pwd).first()
        # print('=============%s' %(obj))
        # if not obj:
        #     ret['code'] = 1001
        #     ret['msg'] = '用户名或者密码错误'
        # # 为用户创建token
        # token = md5(user)
        # # 存在就更新，不存在就创建
        # models.UserToken.objects.update_or_create(user=obj,defaults={'token':token})
        # ret['token'] = token
        return JsonResponse(ret)

ORDER_DICT = {
    1: {
        'name': 'apple',
        'price': 15,
    },
    2: {
        'name': 'dog',
        'price': 100
    }
}
# class Authentication(APIView):
#     """
#     认证类
#     """
#     def authenticate(self,request):
#         token = request._request.GET.get('token')
#         token_obj = models.UserToken.objects.filter(token=token).first()
#         if not token_obj:
#             raise exceptions.AuthenticationFailed('用户认证失败')
#         # 在rest framework内部会将这2个字段赋值给request，以供后续使用
#         return (token_obj.user,token_obj)
#
#     def authenticate_header(self,reqeust):
#         pass

class OrderView(APIView):
    """订单相关业务"""
    # authentication_classes = [] # 添加认证
    def get(self,request,*args,**kwargs):
        print(request.user)
        print(request.auth)
        # print(request.__dict__)
        ret = {'code':1000,'msg':None, 'data': None}
        try:
            ret['data'] = ORDER_DICT
        except Exception as e:
            pass
        return JsonResponse(ret)

class UserInfoView(APIView):
    permission_classes = [MyPermission]
    def get(self,request,*args,**kwargs):
        print(request.user)
        return HttpResponse('用户信息')

　　

urls.py

from django.conf.urls import url
from django.contrib import admin
from API import views
urlpatterns = [
    # url(r'^admin/', admin.site.urls),
    url(r'api/v1/auth', views.AuthView.as_view()),
    url(r'api/v1/order', views.OrderView.as_view()),
    url(r'api/v1/info', views.UserInfoView.as_view()),
]

　　

API/utils/auth.py

#!/usr/bin/env python
# coding:utf-8

from rest_framework import exceptions
from API import models
from rest_framework.authentication import BasicAuthentication

class Authentication(BasicAuthentication):
    def authenticate(self,request):
        token = request._request.GET.get('token')
        token_obj = models.UserToken.objects.filter(token=token).first()
        if not token_obj:
            raise exceptions.AuthenticationFailed('认证失败')
        return (token_obj.user, token_obj)

    def authenticate_header(self, request):
        pass

　　

（4）测试

先get我的token

 先来看看有哪些人

 看一下权限逻辑，确实如果user_type == 3的话，就是没权限，并且message 中定义了，让我滚了。

#!/usr/bin/env python
# coding:utf-8

from rest_framework.permissions import BasePermission

class SVIPPermission(BasePermission):
    message = "必须是SVIP才能访问，你权限太低，滚"
    def has_permission(self,request,view):
        # request.user 表示获取到 UserInfo 这个类的对象
        if request.user.user_type != 3:
            return False
        return True

class MyPermission(BasePermission):
    message = "没有权限查看我，滚"
    def has_permission(self,request,view):
        if request.user.user_type == 3:
            return False
        return True

　　

 再看看order信息吧

 二 权限源码流程

（1）dispatch

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
        #对原始request进行加工，丰富了一些功能
        #Request(
        #     request,
        #     parsers=self.get_parsers(),
        #     authenticators=self.get_authenticators(),
        #     negotiator=self.get_content_negotiator(),
        #     parser_context=parser_context
        # )
        #request(原始request,[BasicAuthentications对象，])
        #获取原生request,request._request
        #获取认证类的对象，request.authticators
        #1.封装request
        request = self.initialize_request(request, *args, **kwargs)
        self.request = request
        self.headers = self.default_response_headers  # deprecate?

        try:
            #2.认证
            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

　　

（2）initial

def initial(self, request, *args, **kwargs):
        """
        Runs anything that needs to occur prior to calling the method handler.
        """
        self.format_kwarg = self.get_format_suffix(**kwargs)

        # Perform content negotiation and store the accepted info on the request
        neg = self.perform_content_negotiation(request)
        request.accepted_renderer, request.accepted_media_type = neg

        # Determine the API version, if versioning is in use.
        version, scheme = self.determine_version(request, *args, **kwargs)
        request.version, request.versioning_scheme = version, scheme

        # Ensure that the incoming request is permitted
        #4.实现认证
        self.perform_authentication(request)
        #5.权限判断
        self.check_permissions(request)
        self.check_throttles(request)

　　

（3）check_permissions

里面有个has_permission这个就是我们自己写的权限判断

def check_permissions(self, request):
        """
        Check if the request should be permitted.
        Raises an appropriate exception if the request is not permitted.
        """
        #[权限类的对象列表]
        for permission in self.get_permissions():
            if not permission.has_permission(request, self):
                self.permission_denied(
                    request, message=getattr(permission, 'message', None)
                )

　　

（4）get_permissions

 def get_permissions(self):
        """
        Instantiates and returns the list of permissions that this view requires.
        """
        return [permission() for permission in self.permission_classes]

　

　

 所以settings全局配置就如下

#全局
REST_FRAMEWORK = {
   "DEFAULT_PERMISSION_CLASSES":['API.utils.permission.SVIPPremission'],
}

　　

三 内置权限

django-rest-framework内置权限BasePermission

默认是没有限制权限

class BasePermission(object):
    """
    A base class from which all permission classes should inherit.
    """

    def has_permission(self, request, view):
        """
        Return `True` if permission is granted, `False` otherwise.
        """
        return True

    def has_object_permission(self, request, view, obj):
        """
        Return `True` if permission is granted, `False` otherwise.
        """
        return True

　　

我们自己写的权限类，应该去继承BasePermission,修改之前写的permission.py文件

# utils/permission.py

from rest_framework.permissions import BasePermission

class SVIPPremission(BasePermission):
    message = "必须是SVIP才能访问"
    def has_permission(self,request,view):
        if request.user.user_type != 3:
            return False
        return True


class MyPremission(BasePermission):
    def has_permission(self,request,view):
        if request.user.user_type == 3:
            return False
        return True

　　

总结：

（1）使用

• 自己写的权限类：1.必须继承BasePermission类；  2.必须实现：has_permission方法

（2）返回值

• True   有权访问
• False  无权访问

（3）局部

• permission_classes = [MyPremission,] 

 （4）全局

REST_FRAMEWORK = {
   #权限
    "DEFAULT_PERMISSION_CLASSES":['API.utils.permission.SVIPPremission'],
}

　　

好了，权限这边还是so easy 的。