The best approach is to think Javascript as PHP code.

The basic steps are:

1. Create a .htaccess file that redirects all JS files (.js) to a index file.


2. In this index file load JS file as a PHP module (require script/$file)


3. Modify all JS files as you need. Now you can embed PHP code.

For instance, add to your .htaccess this line:

RewriteRule .js$ index.php

In your index.php file put something like this:

// Process special JS files

$requested = empty($_SERVER['REQUEST_URI']) ?  : $_SERVER['REQUEST_URI'];

$filename = get_filename($requested);

if (file_ends_with($requested, '.js')) {

     require(www/script/$filename.php);

     exit;

}

And finally in your file.js.php you can embed PHP, use GET and POST params, etc:

<?php header(Content-type: application/x-javascript); ?>

var url = <?php echo $url ?>;

var params = <?php echo $params ?>;



function xxxx().... 

....

In addition, a trick to skip file cache is to add a random number as javascript parameter:

<script type=text/javascript src=scripts/file.js?a=<?php echo rand() ?>></script>

Also, as said in a comment, if your webserver don't allow to modify the .htaccess, you can just ask for the PHP file directly:

<script type=text/javascript src=file.php></script>