I render a page using YUI. and depending on the user I need to change how it is rendered. This change is not something that can be parametrized, it is drastic and different for each user.
Please tell me how can I generate Javascript dynamically?
I personally use a PHP file to pass a JavaScript object made up of some basic session and internal settings, nothing mission-critical as passing information to the client isn't overly secure, but I believe it might follow the same principles as what you are looking for.
Similarly, I use this to display certain elements once the client is logged in, although all the authorization is still done on the server-side. If my session handler gives the PHP file the ok, it outputs a JavaScript object using a PHP heredoc string, otherwise, it doesn't output anything. You can use attributes of this object to compare against, or you could output only the JavaScript for how a certain page should be rendered, based on settings in your PHP file.
HTML:
<script src="common/javascript/php_feeder.php" type="text/javascript"></script>
PHP:
//my session handler authorisation check has been removed
//although you could place your own up here.
//assuming session was authorised
//set content type header
header("content-type: application/x-javascript");
$js_object = <<<EOT
var my_object = {
my_attr: '{$my_attr}',
my_attr2: '{$my_arrt2}',
etc: '{$etc}'
}
EOT;
print($js_object);