一 添加權限

（1）API/utils文件夾下新建premission.py文件，代碼如下：

• message是當沒有權限時，提示的信息

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

from rest_framework.permissions import BasePermission

class SVIPPermission(BasePermission):
    message = "必須是SVIP才能訪問，你權限太低，滾"
    def has_permission(self,request,view):
        # request.user 表示獲取到 UserInfo 這個類的對象
        if request.user.user_type != 3:
            return False
        return True

class MyPermission(BasePermission):
    message = "沒有權限查看我，滾"
    def has_permission(self,request,view):
        if request.user.user_type == 3:
            return False
        return True

（2）settings.py全局配置權限

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

（3）views.py添加權限

• 默認所有的業務都需要SVIP權限才能訪問
• OrderView類裏面沒寫表示使用全局配置的SVIPPremission
• UserInfoView類，因為是普通用戶和VIP用戶可以訪問，不使用全局的，要想局部使用的話，裏面就寫上自己的權限類
• permission_classes = [MyPremission,] #局部使用權限方法

#!/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‘] = ‘用戶名或者密碼錯誤‘
            # 為用戶創建token
            token = md5(user)
            # 存在就更新，不存在就創建
            models.UserToken.objects.update_or_create(user=obj,defaults={‘token‘:token})
            ret[‘token‘] = token
        except Exception as e:
            ret[‘code‘] = 1002
            ret[‘msg‘] = ‘請求異常‘

        # 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‘] = ‘用戶名或者密碼錯誤‘
        # # 為用戶創建token
        # token = md5(user)
        # # 存在就更新，不存在就創建
        # 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):
#     """
#     認證類
#     """
#     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(‘用戶認證失敗‘)
#         # 在rest framework內部會將這2個字段賦值給request，以供後續使用
#         return (token_obj.user,token_obj)
#
#     def authenticate_header(self,reqeust):
#         pass

class OrderView(APIView):
    """訂單相關業務"""
    # authentication_classes = [] # 添加認證
    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(‘用戶信息‘)

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(‘認證失敗‘)
        return (token_obj.user, token_obj)

    def authenticate_header(self, request):
        pass

（4）測試

先get我的token

先來看看有哪些人

看一下權限邏輯，確實如果user_type == 3的話，就是沒權限，並且message 中定義了，讓我滾了。

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

from rest_framework.permissions import BasePermission

class SVIPPermission(BasePermission):
    message = "必須是SVIP才能訪問，你權限太低，滾"
    def has_permission(self,request,view):
        # request.user 表示獲取到 UserInfo 這個類的對象
        if request.user.user_type != 3:
            return False
        return True

class MyPermission(BasePermission):
    message = "沒有權限查看我，滾"
    def has_permission(self,request,view):
        if request.user.user_type == 3:
            return False
        return True

再看看order信息吧

二 權限源碼流程

（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
        #對原始request進行加工，豐富了一些功能
        #Request(
        #     request,
        #     parsers=self.get_parsers(),
        #     authenticators=self.get_authenticators(),
        #     negotiator=self.get_content_negotiator(),
        #     parser_context=parser_context
        # )
        #request(原始request,[BasicAuthentications對象，])
        #獲取原生request,request._request
        #獲取認證類的對象，request.authticators
        #1.封裝request
        request = self.initialize_request(request, *args, **kwargs)
        self.request = request
        self.headers = self.default_response_headers  # deprecate?

        try:
            #2.認證
            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.實現認證
        self.perform_authentication(request)
        #5.權限判斷
        self.check_permissions(request)
        self.check_throttles(request)

（3）check_permissions

裏面有個has_permission這個就是我們自己寫的權限判斷

def check_permissions(self, request):
        """
        Check if the request should be permitted.
        Raises an appropriate exception if the request is not permitted.
        """
        #[權限類的對象列表]
        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 內置權限

django-rest-framework內置權限BasePermission

默認是沒有限制權限

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

我們自己寫的權限類，應該去繼承BasePermission,修改之前寫的permission.py文件

# utils/permission.py

from rest_framework.permissions import BasePermission

class SVIPPremission(BasePermission):
    message = "必須是SVIP才能訪問"
    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

總結：

（1）使用

• 自己寫的權限類：1.必須繼承BasePermission類； 2.必須實現：has_permission方法

（2）返回值

• True 有權訪問
• False 無權訪問

（3）局部

• permission_classes = [MyPremission,]

（4）全局

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

好了，權限這邊還是so easy 的。

Django rest framework（2）----權限