权限

-HyperlinkedIdentityField(用来生成url),传三个参数
		-实例化序列化类的时候,BookSerializer(ret, many=True, context={'request': request})
	-序列化组件的数据校验
		-类比forms组件
		-局部(value是该字段的值)
			-validate_字段名(self,value)
		-全局钩子函数(通过校验值的字典)
			-validate(self,value)
			
	-认证
		-写一个类:
			class LoginAuth():
				# 函数名一定要叫authenticate,接收必须两个参数,第二个参数是request对象
				def authenticate(self, request):
					# 从request对象中取出token(也可以从其它地方取)
					token = request.query_params.get('token')
					# 去数据库过滤,查询
					ret = models.UserToken.objects.filter(token=token)
					if ret:
						# 能查到,说明认证通过,返回空
						# ret.user就是当前登录用户对象,一旦retrun了,后面的认证类都不执行了
						return ret.user,ret
					# 如果查不到,抛异常
					raise exceptions.APIException('您认证失败')
		
		-局部使用:
			-在视图类中加一行:
			-authentication_classes = [LoginAuth, ]
		-全局使用
			-在setting中配置:
				REST_FRAMEWORK={
					'DEFAULT_AUTHENTICATION_CLASSES':['app01.MyAuth.LoginAuth',]
				}
			-局部禁用:				
				-在视图类中加一行:
					-authentication_classes = []
		
	-token表设置超时时间字段
	-token原理
		-'adfasdfasd'
		-'sdafasdfasf|{id:1,'name':}'
		-'asdfasdasd|2'
		
		
	-权限
		权限是什么?
		-写一个类
			class UserPermission():
				# message是出错显示的中文
				message='您没有权限查看'
				def has_permission(self, request, view):
					user_type = request.user.user_type
					# 取出用户类型对应的文字
					# 固定用法:get_字段名字_display()
					user_type_name = request.user.get_user_type_display()
					print(user_type_name)
					if user_type == 2:
						return True
					else:
						return False
		-使用
			-局部使用
				-在视图类中加一行:
				-permission_classes = [LoginAuth, ]
				
			-全局使用
				-在setting中配置
					REST_FRAMEWORK={
						'DEFAULT_PERMISSION_CLASSES':['app01.MyAuth.UserPermission',]
					}
				-局部禁用
					-在视图类中加一行:
					-permission_classes = [ ]


代码示范

from django.shortcuts import render
from rest_framework.views import APIView
from app01 import models
from django.core.exceptions import ObjectDoesNotExist
import hashlib
import time
from django.http import JsonResponse
from app01 import MySerializer


# Create your views here.

def get_token(name):
    # 生成一个md5对象
    md5 = hashlib.md5()
    # 往里添加值,必须是bytes格式
    # time.time()生成时间戳类型,转成字符串,再encode转成bytes格式
    md5.update(str(time.time()).encode('utf-8'))
    md5.update(name.encode('utf-8'))
    return md5.hexdigest()


# 登录
class Login(APIView):
    authentication_classes = []
    def post(self, request, *args, **kwargs):
        response = {'status': 100, 'msg': '登录成功'}
        name = request.data.get('name')
        pwd = request.data.get('pwd')
        try:
            user = models.UserInfo.objects.get(name=name, pwd=pwd)
            # 校验通过,登录成功,生成一个随机字符串(身份标识)token
            token = get_token(name)
            # 保存到数据库
            # update_or_create更新或者创建
            models.UserToken.objects.update_or_create(user=user, defaults={'token': token})
            response['token'] = token
        except ObjectDoesNotExist as e:
            response['status'] = 101
            response['msg'] = '用户名或密码错误'
        except Exception as e:
            response['status'] = 102
            # response['msg']='未知错误'
            response['msg'] = str(e)
        return JsonResponse(response, safe=False)


from rest_framework import exceptions





# class Books(APIView):
#     def get(self, request, *args, **kwargs):
#         response = {'status': 100, 'msg': '查询成功'}
#         # 必须登录以后,才能获取数据
#         # 取出token,取数据库验证,是否登录
#         token = request.query_params.get('token')
#         ret = models.UserToken.objects.filter(token=token)
#         if ret:
#             # 认证通过,是登录用户
#             ret = models.Book.objects.all()
#             book_ser = MySerializer.BookSerializer(ret, many=True)
#             response['data'] = book_ser.data
#         else:
#             response['status'] = 101
#             response['msg'] = '认证不通过'
#
#         return JsonResponse(response, safe=False)

from rest_framework.request import Request
from app01.MyAuth import LoginAuth
class Books(APIView):
    # 列表中,类名不能加括号
    # authentication_classes = [LoginAuth, ]

    def get(self, request, *args, **kwargs):
        # 只要通过认证,就能取到当前登录用户对象
        print(request.user)
        response = {'status': 100, 'msg': '查询成功'}
        ret = models.Book.objects.all()
        book_ser = MySerializer.BookSerializer(ret, many=True)
        response['data'] = book_ser.data
        return JsonResponse(response, safe=False)

# 需求,只能超级用户来查看作者详情,其他人不能看
from app01.MyAuth import UserPermission
class Authors(APIView):
    # permission_classes=[UserPermission,]
    # 局部禁用:
    permission_classes = []
    def get(self, request, *args, **kwargs):


        response = {'status': 100, 'msg': '查询成功'}
        ret = models.Author.objects.all()
        ser = MySerializer.AuthorSerializer(ret, many=True)
        response['data'] = ser.data
        return JsonResponse(response, safe=False)


class User(APIView):
    def get(self, request, *args, **kwargs):
        response = {'status': 100, 'msg': '查询成功'}
        ret = models.UserInfo.objects.all()
        ser = MySerializer.UserSer(ret, many=True)
        response['data'] = ser.data
        return JsonResponse(response, safe=False)

from app01 import models
from rest_framework import exceptions
from rest_framework.authentication import BaseAuthentication


# 用drf的认证,写一个类
class LoginAuth(BaseAuthentication):
    # 函数名一定要叫authenticate,接收必须两个参数,第二个参数是request对象
    def authenticate(self, request):
        # 从request对象中取出token(也可以从其它地方取)
        token = request.query_params.get('token')
        # 去数据库过滤,查询
        ret = models.UserToken.objects.filter(token=token).first()
        if ret:
            # 能查到,说明认证通过,返回空
            # ret.user就是当前登录用户对象
            return ret.user, ret
        # 如果查不到,抛异常
        raise exceptions.APIException('您认证失败')

from rest_framework.permissions import BasePermission
class UserPermission(BasePermission):
    # message是出错显示的中文
    message='您没有权限查看'
    def has_permission(self, request, view):
        user_type = request.user.user_type
        # 取出用户类型对应的文字
        # 固定用法:get_字段名字_display()
        user_type_name = request.user.get_user_type_display()
        print(user_type_name)
        if user_type == 2:
            return True
        else:
            return False