PHP-成功登录后，执行javascript并重定向到新页面

Question

I have this login.php and a javascript to sync the date and time from the client browser to the server of my openwrt router. What I want is, every time a user successfully logs in, it'll execute that javascript and then redirect to status.php which is the home page. Here's what I've tried so far

if ($_POST['username'] == $user[0] && $_POST['password'] == $pass[0]) {
        $_SESSION['loggedin'] = 1;
        echo '<script src="date.js"></script>';
        header("Location: status.php");
        exit;
    }

But it gives me this error:

Warning: Cannot modify header information - headers already sent by (output started at /www/login.php:10) in /www/login.php on line 11

How do I fix it ?

Some of you may think my question is a duplicate but please understand that I need to execute that javascript after successful login.

Answer 1

The problem is that you cannot send the header after echoing. To solve this, ob_start is used to turn output buffering on which means when using echo , no output is sent but instead it is stored in an internal buffer and when we call ob_end_flush after we have called header() , the internal buffer contents will be flushed and output buffering will stop.

Try:

ob_start();
echo '<script src="date.js"></script>';
header("Refresh: 5; url=status.php");
ob_end_flush();

Hope this helps.

Answer 2

you can't put header.. after "echo .." or other html element ..

why you need to put your date.js ?

if ($_POST['username'] == $user[0] && $_POST['password'] == $pass[0]) {
    $_SESSION['loggedin'] = 1;
 //   echo '<script src="date.js"></script>';
    header("Location: status.php");
    exit;
}

Answer 3

将您的JavaScript代码放在您的php代码之外，打开您的php代码，然后在您的JavaScript代码关闭该php之前，将您的JavaScript代码正常放置而不会产生回声，然后再将php的begin和end标记放入