如何从JavaScript中的php文件读取会话变量 [英] How to read a session variable from a php file in JavaScript

问题描述

关于这个主题的问题太多了，但我仍然听不懂.

There have been far too many questions on this subject but I still fail to understand.

案例:

1. 超链接图片
2. 点击图片:检查会话是否存在
3. 如果存在会话，请打开链接
4. 如果会话不存在，请显示登录表单

onclick正在调用JavaScript函数:

onclick is calling a JavaScript function:

var my_global_link = '';
var check = '<?php echo $_SESSION["logged_in"]; ?>';

function show_login( link ) {

     if(check == 1)
     {
         window.location = link;
     }
     else
     {
         my_global_link = link;  
            // .. then show login modal that uses 'js/whitepaper-login.js'
            document.getElementById('light').style.display='block';
            document.getElementById('fade').style.display='block';
            document.getElementById('fade').scrollIntoView(true); 
     }

}

全局变量被另存为另一个php文件:

Global variable is being saved in another php file as :

$_SESSION['logged_in'] = 1;

我无法捕获var check中的会话值.你能建议吗?

I am unable to capture the session value in the var check. Can you advise?

推荐答案

在这里使用jQuery是一个简单的示例，说明如何将PHP $_SESSION放入JavaScript:

Using jQuery here is a simple example of how to get a PHP $_SESSION into your JavaScript:

session.php

session.php

<?php
    session_start();
    $_SESSION['foo'] = 'foo';
    echo $_SESSION['foo']; // this will be echoed when the AJAX request comes in
?>

get_session.html(假定包含jQuery)

get_session.html (assumes jQuery has been included)

<script>
    $(function() {
        $('a').click(function(event){ // use instead of onclick()
            event.preventDefault(); // prevents the default click action

            // we don't need complex AJAX because we're just getting some data
            $.get('session.php', function(sessionData) {
                console.log( sessionData ); // session data will be 'foo'
            });
        });
    });
</script>

<a href="session.php">click</a>

如果成功，您将看到数据，并通过适当地传递数据将其用于其他JavaScript函数.我经常发现json_encode()会话数据很方便，它返回了供JavaScript使用的JSON，但是在这样的简单示例中就没有必要了.

If this is successful you'll see the data and can use it in other JavaScript functions by passing the data appropriately. I often find it handy to json_encode() session data, returning JSON to be used by JavaScript, but there is no need to in a simple example such as this one.

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