Django rest framework（2）----權限

目錄

• Django組件庫之(一) APIView源碼

• Django restframework (1) ----認證

• Django rest framework（2）----權限

• Django rest framework（3）----節流

• Django rest framework（4）----版本

• Django rest framework（5）----解析器

• Django rest framework（6）----序列化

• Django rest framework（7）----分頁

添加權限

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

• message是當沒有權限時，提示的信息

# utils/permission.py


class SVIPPremission(object):
    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(object):
    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

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

（3）views.py添加權限

• 默認全部的業務都須要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，由於是普通用戶和VIP用戶能夠訪問，不使用全局的，要想局部使用的話，裏面就寫上本身的權限類
• permission_classes = [MyPremission,]   #局部使用權限方法

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
    #當前時間，至關於生成一個隨機的字符串
    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):
    '''用於用戶登陸驗證'''

    authentication_classes = []      #裏面爲空，表明不須要認證
    permission_classes = []          #不裏面爲空，表明不須要權限
    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'] = '用戶名或密碼錯誤'
            #爲用戶建立token
            token = md5(user)
            #存在就更新，不存在就建立
            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'
        return JsonResponse(ret)


class OrderView(APIView):
    '''
    訂單相關業務(只有SVIP用戶才能看)
    '''

    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):
    '''
       訂單相關業務(普通用戶和VIP用戶能夠看)
       '''
    permission_classes = [MyPremission,]    #不用全局的權限配置的話，這裏就要寫本身的局部權限
    def get(self,request,*args,**kwargs):

        print(request.user)
        return HttpResponse('用戶信息')

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):
    '''用於用戶登陸驗證'''
    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內部會將這兩個字段賦值給request，以供後續操做使用
        return (token_obj.user,token_obj)

    def authenticate_header(self, request):
        pass

auth.py

（4）測試

普通用戶訪問OrderView,提示沒有權限

 

 普通用戶訪問UserInfoView，能夠返回信息

 

 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這個就是咱們本身寫的權限判斷

    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]

（5）permission_classes

 

 因此settings全局配置就以下

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

 

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

 

咱們本身寫的權限類，應該去繼承BasePermission,修改以前寫的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

• 本身寫的權限類：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'],
}