Day21-Cookie

1. Cookie，有时也用其复数形式 Cookies，指某些网站为了辨别用户身份、进行 session 跟踪而储存在用户本地终端上的数据（通常经过加密）。例如在某个网站上保存了用户名和密码，3个月内免登陆。如果你换台电脑或者浏览器的话，则需要重新登录。就此说明cookie是保存在客户端浏览器上的一个文件。

2.实例---基于cookie实现用户信息验证

当用户名和密码都正确的时候，才跳转到index页面。否则就停留在login.html页面。

2.1 在setting中注释掉下面一句，防止报错

2.2 在urls.py中写路由对应关系

2.3 views.py写后端

dic=user_info.get(u) #如果获取到了，表明用户是存在的。

from django.shortcuts import render,HttpResponse,redirect
from django.urls import reverse
# Create your views here.

user_info={
    'dachengzi':{'pwd':"123123"},
    'kanbazi':{'pwd':"kkkkkkk"},
}
def login(request):
    if request.method=='GET':
        return render(request,'login.html')
    if request.method == 'POST':
        u=request.POST.get('username')
        p=request.POST.get('pwd')
        dic=user_info.get(u)
        if not dic:
            return render(request,'login.html')
        if dic['pwd']==p:
            res=redirect('/index/')
            res.set_cookie('username111',u)
            return res
        else:
            return render(request,'login.html')

def index(request):
    #获取当前已经登录的用户名字
    v=request.COOKIES.get('username111')
    if not v:
        return redirect(request,'/login/')
    return render(request,'index.html',{'current_user':v})

2.4 写前端 index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>欢迎登录：{{current_user}}</h1>
</body>
</html>

2.4 写前端 login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/login/" method="POST">
        <input type="text" name="username" placeholder="用户名"/>
        <input type="password" name="pwd" placeholder="密码"/>
        <input type="submit"/>

    </form>
</body>
</html>

2.5 效果

没有登录之前，是无法访问index页面的。

只有先从login页面登录了以后，才能跳转到index页面。

3. 在Django里面给cookie提供了一些额外的功能。

request.COOKIES-------表示用户发来数据的时候，它里面带的所携带的所有cookie信息。。。从请求中获取cookie
def cookie(request):
    #用户发来请求时，它里面所携带的所有的cookie信息
    request.COOKIES
    request.COOKIES['username111']
    request.COOKIES.get('username111')

设置cookie 键-值对

response.set_cookie('key','value')
def cookie(request):
    #用户发来请求时，它里面所携带的所有的cookie信息
    request.COOKIES
    request.COOKIES['username111']
    request.COOKIES.get('username111')

    response=render(request,'index.html') #通过render，redirect把内容返回给浏览器
    response=redirect('/index/')
    #设置cookie,关闭浏览器后就失效

    response.set_cookie('key','value')  #还可以设置新的cookie 键-值对，也一并返回给浏览器

    return response #里面不仅包含了内容，还包含了cookie的键-值对。

 

4. 默认情况下，关闭浏览器后，cookie就失效了，需要重新登录了。通过下面几种方法可以设置失效时间。

    设置用户名和密码的失效时间-方法1，max_age=None



--------res.set_cookie('username111',u,max_age=10)  设置失效时间为10秒




效果：10秒之后，用户名和密码就失效了，从index自动倒退回到login界面，需要重新登录了。




5. 设置用户名和密码的失效时间-方法2,expires=None


import datetime 
current_date=datetime.datetime.utcnow() 
current_daate=current_date+datetime.timedelta(seconds=5) 
response.set_cookie('username111', "value", expires=current_date)







6. 其它属性
   设置cookie的生效路: ---path='/',意思是在所有的url中都生效。path='/index' 指只在index页面有效。
   生效的域名: domain=None
   https传输: secure=False
　　httponly:  只支持http传输，在JS前端是无法获取的，没有安全不安全一说。示例如下：

设置2个cookie，其中1个有httponly=True属性，对比看效果



在页面上访问的时候，看到了2个cookie




但是在前端却获取不到





7. 增加2个月内免登陆的功能，自己完成。把2个月换算成秒，添加到max_age=XXX里面就可以了。


    注销的本质就是把cookie清除掉。



8. 完善实例，基于cookie实现定制显示数据条数



8.1----cookie在服务器端能读能写，在客户端也是能读能写的。




8.2----------jQuery有个插件叫jQuery-cookie，通过这个插件可以直接去浏览器上去操作cookie了。


从官网下载插件http://plugins.jquery.com/cookie/







 



8.3 用实例来验证，浏览器端确实可以获取到per_page_count这个值。







user_list.html




<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .pagination .page{
            display:inline-block;
            padding:5px;
            background-color:cyan;
            margin:5px;
        }
        .pagination .page.active{
            background-color:brown;
            color:white;
        }
    </style>
</head>
<body>
    <ul>
        {% for item in li %}
            {% include 'li.html' %}
        {%endfor%}
    </ul>
    <div>
        请选择每页显示条数
        <select id="ps" onchange="changePageSize(this)">
            <option value="10">10</option>
            <option value="30">30</option>
            <option value="50">50</option>
            <option value="100">100</option>
        </select>
    </div>
    <div class="pagination">
        {{page_str}}
    </div>
    <script src="/static/jquery-1.12.4.js"></script>
    <script src="/static/jquery.cookie.js"></script>
    <script>
        function changePageSize(ths){
            var v=$(ths).val();
            console.log(v);
            $.cookie('per_page_count',v);
        }
    </script>
</body>
</html>






在Console中也可以看到这个效果。




8.4 服务器端从客户端传过来的cookie中获取到这个值。并且在实例化的时候，把它传递给类。





views.py




from django.shortcuts import render,HttpResponse,redirect
from utils import pagination
from django.urls import reverse
# Create your views here.

LIST=[]
for i in range(1000):
    LIST.append(i)

def user_list(request):
    current_page=request.GET.get('p')
    current_page = int(current_page)

    val=request.COOKIES.get('per_page_count')
    print(val)
    val=int(val)

    page_obj=pagination.Page(current_page,len(LIST),val)
    data=LIST[page_obj.start:page_obj.end]
    page_str=page_obj.page_str("/user_list/")
    return render(request,'user_list.html',{'data':data,'page_str':page_str})

user_info = {
    'dachengzi': {'pwd': "123123"},
    'kanbazi': {'pwd': "kkkkkkk"},
}

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

    if request.method == 'POST':
        u = request.POST.get('username')
        p = request.POST.get('pwd')
        dic = user_info.get(u)

        if not dic:
            return render(request, 'login.html')

        if dic['pwd'] == p:
            res = redirect('/index/')
            res.set_cookie('username111', u)
            return res
        else:
            return render(request, 'login.html')

def index(request):
    # 获取当前已经登录的用户名字
    v = request.COOKIES.get('username111')
    if not v:
        return redirect(request, '/login/')
    return render(request, 'index.html', {'current_user': v})






8.5 完善功能。用户选中每页显示多少条，浏览器上就显示多少条。





代码修改如下：







8.6 完善功能，指定生效的url路径


var v=$.cookie('per_page_count',{'path':"/user_list/"}); 指定路径




9. 至此，程序粘贴如下：


urls.py





from django.conf.urls import url
from django.contrib import admin
from app_ch import views

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^user_list/$', views.user_list),
    url(r'^login', views.login),
    url(r'^index', views.index),
]






 views.py




from django.shortcuts import render,HttpResponse,redirect
from utils import pagination
from django.urls import reverse
# Create your views here.

LIST=[]
for i in range(1000):
    LIST.append(i)

def user_list(request):
    current_page=request.GET.get('p')
    current_page = int(current_page)

    val=request.COOKIES.get('per_page_count')
    print(val)
    val=int(val)

    page_obj=pagination.Page(current_page,len(LIST),val)
    data=LIST[page_obj.start:page_obj.end]
    page_str=page_obj.page_str("/user_list/")
    return render(request,'user_list.html',{'data':data,'page_str':page_str})

user_info = {
    'dachengzi': {'pwd': "123123"},
    'kanbazi': {'pwd': "kkkkkkk"},
}

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

    if request.method == 'POST':
        u = request.POST.get('username')
        p = request.POST.get('pwd')
        dic = user_info.get(u)

        if not dic:
            return render(request, 'login.html')

        if dic['pwd'] == p:
            res = redirect('/index/')
            res.set_cookie('username111', u)
            return res
        else:
            return render(request, 'login.html')

def index(request):
    # 获取当前已经登录的用户名字
    v = request.COOKIES.get('username111')
    if not v:
        return redirect(request, '/login/')
    return render(request, 'index.html', {'current_user': v})





 pagination.py




from django.utils.safestring import mark_safe
class Page:
    def __init__(self,current_page,data_count,per_page_count=10,pager_num=7):
        self.current_page=current_page
        self.data_count=data_count
        self.per_page_count=per_page_count
        self.pager_num=pager_num
    @property
    def start(self):
        return (self.current_page - 1) * self.per_page_count

    @property
    def end(self):
        return self.current_page*self.per_page_count

    @property
    def total_count(self):
        v, y = divmod(self.data_count,self.per_page_count)
        if y:
            v = v+ 1
        return v

    def page_str(self,base_url):
        page_list = []
        if self.total_count < self.pager_num:
            start_index = 1
            end_index = self.total_count + 1
        else:
            if self.current_page <= (self.pager_num + 1) / 2:
                start_index = 1
                end_index = self.pager_num + 1
            else:
                start_index = self.current_page - (self.pager_num - 1) / 2
                end_index = self.current_page + (self.pager_num + 1) / 2
                if (self.current_page + (self.pager_num - 1) / 2) > self.total_count:
                    end_index = self.total_count + 1
                    start_index = self.total_count - self.pager_num + 1

        if self.current_page == 1:
            prev = '<a class="page" href="javascript:void(0)">上一页</a>'
        else:
            prev = '<a class="page" href="%s?p=%s">上一页</a>' % (base_url,self.current_page - 1)
        page_list.append(prev)

        for i in range(int(start_index), int(end_index)):
            if i == self.current_page:
                temp = '<a class="page active" href="%s?p=%s">%s</a>' % (base_url,i, i)
            else:
                temp = '<a class="page" href="%s?p=%s">%s</a>' % (base_url,i, i)
            page_list.append(temp)

        if self.current_page == self.total_count:
            nex = '<a class="page" href="javascript:void(0);">下一页</a>'
        else:
            nex = '<a class="page" href=%s?p=%s>下一页</a>' % (base_url,self.current_page + 1)
        page_list.append(nex)

        jump = '''
            <input type='text'/><a onclick='jumpTo(this,"%s?p=");'>Go</a>
            <script>
                function jumpTo(ths,base){
                    var val=ths.previousSibling.value;
                    location.href=base+val;
                }
            </script>
        '''%(base_url)

        page_list.append(jump)
        page_str = mark_safe("".join(page_list))
        return page_str





 user_list.html




<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .pagination .page{
            display:inline-block;
            padding:5px;
            background-color:cyan;
            margin:5px;
        }
        .pagination .page.active{
            background-color:brown;
            color:white;
        }
    </style>
</head>
<body>
    <ul>
        {% for i in data%}
            <li>{{i}}</li>
        {% endfor %}
    </ul>
    <div>
        选择每页显示的条数：
        <select id="ps" onchange="changePageSize(this)">
            <option value="10">10</option>
            <option value="30">30</option>
            <option value="50">50</option>
        </select>
    </div>
    <div class="pagination">
        {{page_str}}
    </div>
    <script src="/static/jquery-1.12.4.js"></script>
    <script src="/static/jquery.cookie.js"></script>
    <script>
        $(function(){
            var v=$.cookie('per_page_count',{'path':"/user_list/"});
            $('#ps').val(v);
        });
        function changePageSize(ths){
            var v=$(ths).val();
            $.cookie('per_page_count',v,{'path':"/user_list/"});
            location.reload();
        }
    </script>
</body>
</html>






login.html




<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/login/" method="POST">
        <input type="text" name="username" placeholder="用户名"/>
        <input type="password" name="pwd" placeholder="密码"/>
        <input type="submit"/>
    </form>
</body>
</html>






index.html




<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>欢迎登录：{{current_user}}</h1>
</body>
</html>






 


 10. 带签名的cookie


-------明文：


获取cookie： request.COOKIES.get('......')


设置cookie： response.set_cookie(.....)


--------密文：


加密解密如下，注意盐要对应，否则解密会不成功。


obj=HttpResponse('s')  #返回给客户端的数据
obj.set_signed_cookie('username',"kangbazi",salt='XXX') 通过XXX这个字符串，对cookie的内容进行加密。
request.get_signed_cookie('username',salt="XXX") 服务器端获取得时候，需要解密。






11. 用装饰器实现用户验证
假设这里不仅有index页面需要验证，然后还有一个order页面也需要验证。我们尝试用装饰器来实现。


新建1个order页面，用FBV装饰器来实现。




用另外一种方法CBV实现



现在还没有登录，尝试用get访问的时候，效果如下：




在dispatch方法执行完了以后，才执行下面的方法。





from django.shortcuts import render,HttpResponse,redirect
from utils import pagination
from django.urls import reverse
# Create your views here.

LIST=[]
for i in range(1000):
    LIST.append(i)

def user_list(request):
    current_page=request.GET.get('p')
    current_page = int(current_page)

    val=request.COOKIES.get('per_page_count')
    print(val)
    val=int(val)

    page_obj=pagination.Page(current_page,len(LIST),val)
    data=LIST[page_obj.start:page_obj.end]
    page_str=page_obj.page_str("/user_list/")
    return render(request,'user_list.html',{'data':data,'page_str':page_str})

user_info = {
    'dachengzi': {'pwd': "123123"},
    'kanbazi': {'pwd': "kkkkkkk"},
}

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

    if request.method == 'POST':
        u = request.POST.get('username')
        p = request.POST.get('pwd')
        dic = user_info.get(u)

        if not dic:
            return render(request, 'login.html')

        if dic['pwd'] == p:
            res = redirect('/index/')
            res.set_cookie('username111', u)
            return res
        else:
            return render(request, 'login.html')

def auth(func):
    def inner(request,*args,**kwargs):
        v = request.COOKIES.get('username111')
        if not v:
            return redirect(request, '/login/')
        return func(request,*args,**kwargs)
    return inner

@auth
def index(request):
    # 获取当前已经登录的用户名字
    v = request.COOKIES.get('username111')
    return render(request, 'index.html', {'current_user': v})

from django import views
from django.utils.decorators import method_decorator
class Order(views.View):
    @method_decorator(auth)
    def dispatch(self,request,*args,**kwargs):
        return super(Order,self).dispatch(request,*args,**kwargs)

    def get(self,request):
        v = request.COOKIES.get('username111')
        return render(request, 'index.html', {'current_user': v})
    
    def post(self,request):
        v = request.COOKIES.get('username111')
        return render(request, 'index.html', {'current_user': v})

def order(request):
    # 获取当前已经登录的用户名字
    v = request.COOKIES.get('username111')
    return render(request, 'index.html', {'current_user': v})








可以更优化，把装饰器写到类的上面。



FBV和CBV两种方法实现装饰器的比较




至此程序如下：

urls.py




from django.conf.urls import url
from django.contrib import admin
from app_ch import views

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^user_list/$', views.user_list),
    url(r'^login', views.login),
    url(r'^index', views.index),
    url(r'^order', views.Order.as_view()),
]






views.py




from django.shortcuts import render,HttpResponse,redirect
from utils import pagination
from django.urls import reverse
# Create your views here.

LIST=[]
for i in range(1000):
    LIST.append(i)

def user_list(request):
    current_page=request.GET.get('p')
    current_page = int(current_page)

    val=request.COOKIES.get('per_page_count')
    print(val)
    val=int(val)

    page_obj=pagination.Page(current_page,len(LIST),val)
    data=LIST[page_obj.start:page_obj.end]
    page_str=page_obj.page_str("/user_list/")
    return render(request,'user_list.html',{'data':data,'page_str':page_str})

user_info = {
    'dachengzi': {'pwd': "123123"},
    'kanbazi': {'pwd': "kkkkkkk"},
}

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

    if request.method == 'POST':
        u = request.POST.get('username')
        p = request.POST.get('pwd')
        dic = user_info.get(u)

        if not dic:
            return render(request, 'login.html')

        if dic['pwd'] == p:
            res = redirect('/index/')
            res.set_cookie('username111', u)
            return res
        else:
            return render(request, 'login.html')

def auth(func):
    def inner(request,*args,**kwargs):
        v = request.COOKIES.get('username111')
        if not v:
            return redirect(request, '/login/')
        return func(request,*args,**kwargs)
    return inner

@auth
def index(request):
    # 获取当前已经登录的用户名字
    v = request.COOKIES.get('username111')
    return render(request, 'index.html', {'current_user': v})

from django import views
from django.utils.decorators import method_decorator

@method_decorator(auth,name='dispatch')
class Order(views.View):
    def get(self,request):
        v = request.COOKIES.get('username111')
        return render(request, 'index.html', {'current_user': v})

    def post(self,request):
        v = request.COOKIES.get('username111')
        return render(request, 'index.html', {'current_user': v})

def order(request):
    # 获取当前已经登录的用户名字
    v = request.COOKIES.get('username111')
    return render(request, 'index.html', {'current_user': v})







 utils-->pagination.py




from django.utils.safestring import mark_safe
class Page:
    def __init__(self,current_page,data_count,per_page_count=10,pager_num=7):
        self.current_page=current_page
        self.data_count=data_count
        self.per_page_count=per_page_count
        self.pager_num=pager_num
    @property
    def start(self):
        return (self.current_page - 1) * self.per_page_count

    @property
    def end(self):
        return self.current_page*self.per_page_count

    @property
    def total_count(self):
        v, y = divmod(self.data_count,self.per_page_count)
        if y:
            v = v+ 1
        return v

    def page_str(self,base_url):
        page_list = []
        if self.total_count < self.pager_num:
            start_index = 1
            end_index = self.total_count + 1
        else:
            if self.current_page <= (self.pager_num + 1) / 2:
                start_index = 1
                end_index = self.pager_num + 1
            else:
                start_index = self.current_page - (self.pager_num - 1) / 2
                end_index = self.current_page + (self.pager_num + 1) / 2
                if (self.current_page + (self.pager_num - 1) / 2) > self.total_count:
                    end_index = self.total_count + 1
                    start_index = self.total_count - self.pager_num + 1

        if self.current_page == 1:
            prev = '<a class="page" href="javascript:void(0)">上一页</a>'
        else:
            prev = '<a class="page" href="%s?p=%s">上一页</a>' % (base_url,self.current_page - 1)
        page_list.append(prev)

        for i in range(int(start_index), int(end_index)):
            if i == self.current_page:
                temp = '<a class="page active" href="%s?p=%s">%s</a>' % (base_url,i, i)
            else:
                temp = '<a class="page" href="%s?p=%s">%s</a>' % (base_url,i, i)
            page_list.append(temp)

        if self.current_page == self.total_count:
            nex = '<a class="page" href="javascript:void(0);">下一页</a>'
        else:
            nex = '<a class="page" href=%s?p=%s>下一页</a>' % (base_url,self.current_page + 1)
        page_list.append(nex)

        jump = '''
            <input type='text'/><a onclick='jumpTo(this,"%s?p=");'>Go</a>
            <script>
                function jumpTo(ths,base){
                    var val=ths.previousSibling.value;
                    location.href=base+val;
                }
            </script>
        '''%(base_url)

        page_list.append(jump)
        page_str = mark_safe("".join(page_list))
        return page_str






login.html




<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/login/" method="POST">
        <input type="text" name="username" placeholder="用户名"/>
        <input type="password" name="pwd" placeholder="密码"/>
        <input type="submit"/>
    </form>
</body>
</html>






index.html




<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>欢迎登录：{{current_user}}</h1>
</body>
</html>
















        

	      

	    

	  

	  

	    
      
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          原文地址：https://www.cnblogs.com/momo8238/p/7680917.html