47°

11.DRF-权限

Django rest framework源码分析(2)----权限

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
# utils/permission.py

class SVIPPremission(object): 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(object): 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

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

(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
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 BaseAuthentication
from API.utils.permission import SVIPPremission,MyPremission

ORDER_DICT = { 1:{ 'name':'apple', 'price':15 }, 2:{ 'name':'dog', 'price':100 } }

def md5(user): import hashlib import time #当前时间,相当于生成一个随机的字符串 ctime = str(time.time()) m = hashlib.md5(bytes(user,encoding='utf-8')) m.update(bytes(ctime,encoding='utf-8')) return m.hexdigest()

class AuthView(APIView): '''用于用户登录验证'''

authentication_classes = []      #里面为空,代表不需要认证
permission_classes = []          #不里面为空,代表不需要权限
def post(self,request,*args,**kwargs):
    ret = {'code':1000,'msg':None}
    try:
        user = request._request.POST.get('username')
        pwd = request._request.POST.get('password')
        obj = models.UserInfo.objects.filter(username=user,password=pwd).first()
        if not obj:
            ret['code'] = 1001
            ret['msg'] = '用户名或密码错误'
        #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'
    return JsonResponse(ret)

class OrderView(APIView): ''' 订单相关业务(只有SVIP用户才能看) '''

def get(self,request,*args,**kwargs):
    self.dispatch
    #request.user
    #request.auth
    ret = {'code':1000,'msg':None,'data':None}
    try:
        ret['data'] = ORDER_DICT
    except Exception as e:
        pass
    return JsonResponse(ret)

class UserInfoView(APIView): ''' 订单相关业务(普通用户和VIP用户可以看) ''' permission_classes = [MyPremission,] #不用全局的权限配置的话,这里就要写自己的局部权限 def get(self,request,*args,**kwargs):

    print(request.user)
    return HttpResponse('用户信息')

# urls.py
from django.contrib import admin
from django.urls import path
from API.views import AuthView,OrderView,UserInfoView

urlpatterns = [
    path('admin/', admin.site.urls),
    path('api/v1/auth/',AuthView.as_view()),
    path('api/v1/order/',OrderView.as_view()),
    path('api/v1/info/',UserInfoView.as_view()),
]
# API/utils/auth/py
# auth.py

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


class Authentication(BaseAuthentication):
    '''用于用户登录验证'''
    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内部会将这两个字段赋值给request,以供后续操作使用
        return (token_obj.user,token_obj)

    def authenticate_header(self, request):
        pass

(4)测试

普通用户访问OrderView,提示没有权限

普通用户访问UserInfoView,可以返回信息

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]

(5)permission_classes

所以settings全局配置就如下

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

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'],
}

本文转载自博客园,原文链接:https://www.cnblogs.com/yanadoude/p/13171901.html

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