django之cookie与session

-cookie
            -是什么?存储在客户端浏览器上的键值对
        -原理
            是服务器产生,发给客户端浏览器,浏览器保存起来,下次发请求,会携带这个键值对到服务器
        -Cookie的覆盖 
            先写了一个键值对,后来再写,会把原来的值覆盖掉
        -cookie使用(**********************)
            -写cookie:在Httpresponse这个对象上写
                -obj.set_cookie(key,value)
            -取cookie:从request对象中取,取出来是个字典request.COOKIES
            -删除cookie:
                obj.delete_cookie('name')
                
            -登录认证装饰器,登录之后才能访问固定的页面
                def login_auth(func):
                    def inner(request, *args, **kwargs):
                        # 拿到之前访问的路径
                        # 这个不行,因为取不到数据部分
                        # url=request.path
                        url = request.get_full_path()

                        is_login = request.COOKIES.get('is_login')
                        if is_login:
                            res = func(request, *args, **kwargs)
                            return res
                        else:
                            return redirect('/login/?next=%s' % url)

                    return inner
        -cookie的其他属性
            -加盐cooke
            -超时时间max_age,传一个秒的时间
            -超时时间expires,传一个datatime对象
            -path='/',可以设置路径,设置路径之后,path='/index/',只有访问index的时候,才会携带cookie过来
            -domain 设置域名下有效domain='map.baidu.com'
            -secure=False, (默认是false,设置成True浏览器将通过HTTPS来回传cookie)
            -httponly=True 只能https协议传输，无法被JavaScript获取（不是绝对，底层抓包可以获取到也可以被覆盖)
        -session
            -解决cookie不安全的问题,
            -存在服务器上的键值对{'sdaf随机字符串':{name:lqz,pwd:123}}
            -用session必须跟cookie连用
        -session使用(****************)
            -设置值
                -request.session['name']='lqz'
                -如果设置多个,它会以字典的形式存储到session表中的session_data中
            -生成session时:
                1 生成随机字符串:dfasfasdfa
                2 取数据库存储
                3 写入cookie(set_cookie('sessionid','dfasfasdfa'))
            -取值
                name=request.session['name']
            -执行流程:
                -取到cookie的随机字符串
                -取session表中根据随机字符串查询,查询出session_data这个字典,然后把字典中name返回
                
            -删除值
                -# 取出cookie,随机字符串,去数据库删除随机字符串是当前值的记录
                    request.session.delete()
                -#既删除cookie,又删除数据库
                    request.session.flush()
        -session其他属性
            -request.session.setdefault('k1',123) # 存在则不设置
            -取到随机字符串,浏览器带过来的cookie的值
                print(request.session.session_key)
                内部
                request.COOKIES.get('sessionid')
            -清空失效的session
                request.session.clear_expired()
            -校验sessionid是否存在
                request.session.exists("session_key")
            -
        


        session的配置
            -不但能放到数据库,还能放到文件中,redis(内存数据库)

-----------------------------基于cookie的登录装饰器--------------------------------------------
def login_auth(func):
    def inner(request, *args, **kwargs):
        url = request.get_full_path()
        is_login = request.COOKIES.get('is_login')
        if is_login:
            res = func(request, *args, **kwargs)
            return res
        return redirect('/login/?next=%s'%url)

    return inner

def login(request):
    if request.method == "GET":
        return render(request, 'login.html')
    else:
        next = request.GET.get('next')
        name = request.POST.get('name')
        pwd = request.POST.get('pwd')
        if name == 'zjh' and pwd == '123':
            if next:
                obj = redirect(next)
            else:
                obj = redirect('/shopping/')
            obj.set_cookie('is_login', True)
            return obj
        else:
            return HttpResponse('用户名或密码错误')


@login_auth
def order(request):
    return HttpResponse('我是看登录页面的,登录才能看')



def shopping(request):
    return HttpResponse('我是看购物页面的,登录才能看')

def set_cookie(request):
    obj = HttpResponse('我是set_cookie')
    # obj.set_signed_cookie('name','zjh',salt='123')
    obj.set_cookie('name','zjh',max_age=20)
    return obj

def get_set_cookie(request):

    name = request.COOKIES.get('name')
    print(name)
    return HttpResponse('获取加盐的cookie')
# -------------------------session--------------------------------------

def delete_session(request):

    # request.session.flush()

    request.session['name']='zjh'
    request.session['pwd']='123'

    return HttpResponse('set_session')


def get_session(request):
    name=request.session['name']
    print(name)
    return HttpResponse('get_session')
# --------------------------------------session登录装饰器--------------------------------------






def session_auth(func):
    def inner(request,*args,**kwargs):
        url = request.get_full_path()
        # is_session = request.session.get('is_session')
        is_session = request.COOKIES.get('sessionid')
        print(is_session)
        if is_session:
            res = func(request,*args,**kwargs)
            # request.session.flush()
            return res
        else:
            return redirect('/session_login/?next=%s'%url)
    return inner

def session_login(request):
    if request.method == 'GET':
        return render(request,'login.html')
    else:

        request.session['name'] = 'zjh'
        request.session['pwd'] = '123'

        next = request.GET.get('next')
        name = request.POST.get('name')
        pwd = request.POST.get('pwd')

        # user_name = request.session['name']
        # user_pwd = request.session['pwd']
        # 
        # user_name = request.session.get('name')
        # user_pwd = request.session.get('pwd')
        print(user_name,user_pwd)
        if name==user_name and pwd==user_pwd:
            # request.session['is_session'] = True
            if next:
                print(next)
                return redirect(next)

            else:
                obj = redirect('/shopping/')
            return obj

        return HttpResponse('用户名或密码错误')

@session_auth
def session_order(request):
    return HttpResponse('我是order')