如果 JS 会话变量为 null，如何避免 500 Internal Server Error

Question

我创建这个脚本是为了从各种网络资源中读取内容。此脚本更新所有通知（邮件、post、朋友）和他们自己的下拉列表 window 的详细信息以及两侧更新栏。我在我的顶部 manu.php 页面中使用了这个脚本。

此脚本适用于 login 用户。

现在我用 JavaScript var uid = '<? echo $session->id; ?>'; 传递一个会话 ID 变量所以当用户没有登录时，我的浏览器控制台显示 500 Internal Server Error 因为这里会话没有 ID 所以它通过 uid=''

我该如何克服这个问题？

这是我的 JavaScript 脚本：

var uid = '<? echo $session->id; ?>';
    function addmailno(type, msg){
    //Do something for display mail/friend/post notification
    }

    function addmailup(type, msg){
    //Do something for display mail/post/friend drop-down.
    }

    function addside(type, msg){
    //Do something for display all friend/new post in side bar.
    }

    function waitFormailno(){
        $.ajax({
            type: "GET",
            url: "serverforupandside.php",
            cache: false,
            async : false,
            dataType : 'json',
            data: "uid="+ uid,
            timeout:15000, 
            success: function(data){ 
                addmailno("MyDivClass", data);
                addmailup("MyDivClass", data);
                addside("MyDivId", data);
                setTimeout(waitFormailno, 15000);
            },
            error: function(){
                setTimeout(waitFormailno, 15000); 
            }
        });
    }

$(document).ready(function(){
    waitFormailno();
});

serverforupandside.php

<?php
include("db.php");
include_once("mysession.php");

while (true) {
if($_GET['uid']){
global $dbh;

//All php query is here one after one

//Output is here by data
$data = array();

$data['upmail'] = $upmail;
$data['upfollow'] = $upfollow;
$data['uppost'] = $uppost;
// etc all

    if (!empty($data)) {
        echo json_encode($data);
        flush();
        mysqli_close($dbh);
    }
    }
    mysqli_close($dbh);
}
?>

Answer 1

您的Javascript代码应修改为：

function waitFormailno(){
        $.ajax({
            type: "GET",
            url: "serverforupandside.php",
            cache: false,
            async : false,
            dataType : 'json',
            data: "uid="+ uid,
            timeout:15000, 
            success: function(data){ 
                addmailno("MyDivClass", data);
                addmailup("MyDivClass", data);
                addside("MyDivId", data);
            }
        });
    }

$(document).ready(function(){
    setInterval(waitFormailno, 15000); // calls a function or evaluates an expression at specified intervals (in milliseconds)
});

PHP代码：

<?php
include("db.php");
include_once("mysession.php");

if (!empty($_GET['uid'])) {
    global $dbh;

    //All php query is here one after one

    //Output is here by data
    $data = array();

    $data['upmail']   = $upmail;
    $data['upfollow'] = $upfollow;
    $data['uppost']   = $uppost;
    // etc all

    if (!empty($data)) {
        echo json_encode($data);
    }


}

此外，您应该在填充 $data 数组之前添加验证。

如果 JS 会话变量为 null，如何避免 500 Internal Server Error

How to avoid 500 Internal Server Error if a JS session variable null

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