How to display custom style based on theme option select box

Question

How can I display a different style snippet if a user selects and option from my theme options page select box.

For example. To show the sidebar on the right a user would select "Right" and the default stylesheet would be used. However, if they chose "Left" to display it on the left, a small style snippet would appear that overrides the default stylesheet.

This is how I do it for checkboxes if that helps.

<?php if ( of_get_option('show_post_sidebar', false ) ) { ?>
        <!-- default styles would be used -->
    <?php } else {?>
        <style type="text/css" media="screen">
            .post{width:720px}
        </style>
    <?php } ?>

Answer 1

Just put your dynamic CSS inside of a callback function, hooked into wp_print_script, e.g.

function mytheme_custom_css() {
    ?>
    <script type="text/css">
    <?php if ( of_get_option('show_post_sidebar', true ) ) { ?>
        .post{width:720px}
    <?php } ?>
    </script>
    <?php
}
add_action( 'wp_print_scripts', 'mytheme_custom_css' );

Add as few, or as many, conditional CSS rules as you need.

Answer 2

I myself have been researching this for my personal blog. There seem to be a few plugins if you're not opposed to using one.

Edit: WordPress appears to have a built-in function for this.

Edit again: I'm sorry but I think I mis-read your question. I assumed that you were looking for a way to change themes based on user preference. I guess I should have read more carefully rather than skimming quickly.