如何在PHP变量中存储当前URL并中断对$ _SERVER ['REQUEST_URI']的引用？

Question

Say I'm on /page_1.php . I run the following code under a certain condition:

global $URL_BEFORE_PAGE2;
$URL_BEFORE_PAGE2 = $_SERVER['REQUEST_URI'];
header('location: /page_2.php');

I am now on /page_2.php . This page contains the following link:

<a href="<?=$URL_BEFORE_PAGE2?>">Return to Previous Page</a>

PROBLEM: The link using $URL_BEFORE_PAGE2 points to /page_2.php instead of the expected /page_1.php .

I assume the problem is that $URL_BEFORE_PAGE2 is storing a reference to $_SERVER['REQUEST_URI'] instead of just storing the value. How can I keep the original value of $URL_BEFORE_PAGE2 without it updating every time $_SERVER['REQUEST_URI'] changes?

Answer 1

On page_1.php, use the following code to create a session that will store the uri

session_start();

$_SESSION['URL_BEFORE_PAGE2'] = $_SERVER['REQUEST_URI'];
header('location: /index2.php');

On page_2.php, simply use the session to get the uri again

<?php
    session_start();
?>
<a href="<?=$_SESSION['URL_BEFORE_PAGE2']?>">Return to Previous Page</a>

More info on sessions

session_start()

Answer 2

You could do that with javascript:

 function goBack() { window.history.back(); } 

 <button onclick="goBack()">Go Back</button> 

You could do that with PHP like this:

 <?php header('Location: ' . $_SERVER['HTTP_REFERER']); ?>