Stylesheet Switcher in jQuery.
In response to the 'newbie followup' comment, I will try to make it a little more instructional.
The page I was playing with to test on while writing can be found here.
Page Display
You're going to want to have your current stylesheet displayed in a <link> tag in the <head> of each of your pages. The <link> tag will need an id for reference later in JavaScript. Something like:
<?php
// Somewhere in the server side code, $current_stylesheet is read from the user's
// "preferences" - most likely from a database / session object
$current_stylesheet = $user->stylesheet;
?>
<link href='<?php echo $current_stylesheet ?>' rel='stylesheet' type='text/css' id='stylelink' />
Changing the preference
Once you are displaying the users stylesheet, you need a way to change it. Create a <form> that will send a request to the server when the user changes their stylesheet:
<form method="GET" id="style_form" >
<select name="stylesheet" id="styleswitch">
<option value="css1.css">Black & White</option>
<option value="css2.css" selected="selected">Shades of Grey</option>
</select>
<input value='save' type='submit' />
</form>
Server Side
Now, without jQuery, submitting this form should GET (you could change it to POST if you like) stylesheet={new stylesheet} on the current page. So somewhere in your bootstrap / sitewide include file, you do a check for it, a php sample:
$styles = array(
'css1.css' => 'Black & White',
'css2.css' => 'Shades of Grey',
);
if (!empty($_GET["sytlesheet"]) {
// VALIDATE IT IS A VALID STYLESHEET - VERY IMPORTANT
// $styles is the array of styles:
if (array_key_exists($_GET["stylesheet"], $styles)) {
$user->stylesheet = $_GET["stylesheet"];
$user->save();
}
}
Live Preview
At this point, you have a functioning styleswitcher for the lame people without javascript. Now you can add some jQuery to make this all happen a little more elegantly. You'll want to use the jQuery Form Plugin to make a nice ajaxForm() function, that will handle submitting the form. Add the jQuery and jQuery Form library to the page:
<script type='text/javascript' src='/js/jquery.js'></script>
<script type='text/javascript' src='/js/jquery.form.js'></script>
Now that we have the libraries included -
$(function() {
// When everything has loaded - this function will execute:
$("#style_form").ajaxForm(function() {
// the style form will be submitted using ajax, when it succeeds:
// this function is called:
$("#thediv").text('Now Using: '+$('#styleswitch').val());
});
$("#styleswitch").change(function() {
// When the styleswitch option changes, switch the style's href to preview
$("#stylelink").attr('href', $(this).val());
// We also want to submit the form to the server (will use our ajax)
$(this).closest('form').submit();
});
// now that you have made changing the select option submit the form,
// lets get rid of the submit button
$("#style_form input[type=submit]").remove();
});