Django-rest-framework源码分析----权限

时间:2021-10-18 16:08:49

目录

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')
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()),
]

urls.py

# API/utils/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

auth.py

(4)测试

普通用户访问OrderView,提示没有权限

Django-rest-framework源码分析----权限

普通用户访问UserInfoView,可以返回信息

Django-rest-framework源码分析----权限

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

Django-rest-framework源码分析----权限

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'],
}