如何知道是否有人通过 javascript 登录？
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how to know if someone is logged via javascript?
提问by karim79
in php i would do
在 php 我会做
if (isset($_COOKIE['user']) && $_COOKIE['user'] == $valueFromDb)
echo 'logged';
But in javascript how can I check it?
但是在 javascript 中我如何检查它？
Thanks
谢谢
回答by karim79
There is no reliable way to do this without making a request to the server, since the session might have expired on the server side. In one project, I do it the following, imperfect way:
如果不向服务器发出请求，就没有可靠的方法来执行此操作，因为会话可能已在服务器端过期。在一个项目中，我采用以下不完美的方式：
checkAuth() {
var logged = (function() {
var isLogged = null;
$.ajax({
'async': false,
'global': false,
'url': '/user/isLogged/',
'success': function(resp) {
isLogged = (resp === "1");
}
});
return isLogged;
})();
return logged;
}
I say imperfect because it makes a synchronous request which temporarily locks up the browser. It does have an advantage in that checkAuth()can be reliably called from any part of the client-side application since it forces the browser to wait for the result before continuing execution of the JS code, but that's about it.
我说不完美是因为它发出了一个同步请求，暂时锁定了浏览器。它确实有一个优点，checkAuth()可以从客户端应用程序的任何部分可靠地调用，因为它强制浏览器在继续执行 JS 代码之前等待结果，但仅此而已。
The alternative, asynchronous (non-locking) approach would be to do something like this:
另一种异步（非锁定）方法是执行以下操作：
$.ajax({
'url': '/user/isLogged/',
'success': function(resp) {
if(resp === "1") {
// do your thing here, no need
// for async: false
}
}
});
回答by Arturo Igualada
When you want to know if user is logged on a page to do some type of special action, I usually use a hidden input with a special name that is checked on js. If the user is logged you put that on a master page or something like that and then in js check if it exist to know if the user is logged.
当您想知道用户是否登录页面执行某种类型的特殊操作时，我通常使用在 js 上检查的具有特殊名称的隐藏输入。如果用户已登录，则将其放在母版页或类似内容上，然后在 js 中检查它是否存在以了解用户是否已登录。
Something like:
就像是：
<input type="hidden" class="UserIsLogged" />
<script type="text/javascript">
if ($(".UserIsLogged").length > 0) {
//User is logged
}
</script>
回答by bmargulies
You are mixing up server-side processing (php) with client side processing (javascript). On the client side this information does not exist unless the server has provided it in some framework-specific way.
您将服务器端处理 (php) 与客户端处理 (javascript) 混为一谈。在客户端，除非服务器以某种特定于框架的方式提供此信息，否则此信息不存在。
回答by Mohammed Swillam
Yes. check out this question: Create, read, and erase cookies with jQuery
是的。查看这个问题：使用 jQuery 创建、读取和删除 cookie
a plugin to make it even easier for you: http://plugins.jquery.com/project/cookie
一个让你更轻松的插件：http: //plugins.jquery.com/project/cookie
