I know how to redirect a page using:

header("location:my_page.php");

However, I want to redirect a user back to where they came from. Basically, I have a login form on each page of my site. Once they click submit (no matter what area they are in,) they will be logged in. Instead of redirecting a page that I have set (ie. members_only.php), I want to send them back to where they came from. I know this can be done in javascript, but I don't want javascipt. Any ideas for PHP?

You could pass session variables from each page and use it in the header()

$_SERVER["HTTP_REFERER"] will work, but can be spoofed. The session idea mentioned would be best, but if you don't already have one open, I'd just use a form variable/CGI parameter (again, can be spoofed).

Originally Posted by choskins102

I know how to redirect a page using:

header("location:my_page.php");

However, I want to redirect a user back to where they came from. Basically, I have a login form on each page of my site. Once they click submit (no matter what area they are in,) they will be logged in. Instead of redirecting a page that I have set (ie. members_only.php), I want to send them back to where they came from. I know this can be done in javascript, but I don't want javascipt. Any ideas for PHP?

1. Maybe you should get the page they are every time they are on your website. Maybe store them in a session or something. and whenever you want to redirect them, you can just refer to that.

2. HTTP_REFERER can also be used which is the thing that first came to mind.

I would use both features. On the page they are viewing, you can make it so it sets the page they are viewing in a session and then on that redirect, you can make it redirect with the header.

I provided some simple examples. There is a huge downside to the first two of them, though. If you need to collect the URL every time they view a page, you will be paying the price by slowing down your server (server request can slow down the page). If the page only needs to be collected once and stored in a session, then it's different. You can block the server request from loading by seeing if the session exist or not. Here's some examples:

PHP Code:

<?php
/** Collect the server request, store it in a session, and do the redirect, and if they are viewing random pages before hand, you can always unset the old session and re-collect the new one **/

//simple server request and redirect
$_SESSION['page'] = $_SERVER['HTTP_REFERER'];

header("location:" .$_SESSION['page']. "");

//are they always on a random page on your site? if the session exist, unset the old one and make a new one
if((isset($_SESSION['page'])) || (session_is_registered($_SESSION['page']))) {
unset($_SESSION['page']);
//make the new session for the new page
 $_SESSION['page'] = $_SERVER['HTTP_REFERER'];
} else {
//just collect it, don't unset it if it doesn't exist
 $_SESSION['page'] = $_SERVER['HTTP_REFERER'];
}

//heres the third way, if they are not viewing a random URL on your site, this is good to use, but probably not :(
if((isset($_SESSION['page'])) || (session_is_register($_SESSION['page']))) {
//do nothing, we don't have to make the server request
} else {
//the session doesn't exist, so get it
 $_SESSION['page'] = $_SERVER['HTTP_REFERER']; 
}

//and then of course, do the re-direct whenever you want like I did in the example I provided up top using the header function
 header("location:" .$_SESSION['page']. "");
 ?>