cdn-rewrite.php

<?php
/*
Plugin Name: CDN Rewrite
Plugin URI: http://voceconnect.com/
Description: Rewrites asset URLs to CDN
Version: 0.1
Author: Chris Scott, Michael Pretty
Author URI: http://voceconnect.com/
*/

require_once('voce-settings.php');

class CDN_Rewrite {

	const OPTION_GENERAL = 'cdn_general';

	private $submenu_general;

	private $cdn_root_url;
	private $file_extensions;

	private $css_file_extensions;
	private $css_cdn_root_url;

	private $js_file_extensions;
	private $js_cdn_root_url;

	private $blog_details;

	public function __construct() {
		$this->cdn_root_url = untrailingslashit($this->get_setting('root_url'));
		$this->file_extensions = $this->get_setting('file_extensions');

		$this->css_cdn_root_url = untrailingslashit($this->get_setting('css_root_url'));
		$this->css_file_extensions = $this->get_setting('css_file_extensions');

		$this->js_cdn_root_url = untrailingslashit($this->get_setting('js_root_url'));
		$this->js_file_extensions = $this->get_setting('js_file_extensions');
}

	public function initialize() {
		if (!class_exists('Voce_Settings')) {
			return;
		}

		add_action('admin_menu', array($this, 'add_options_page'));
		if ('' == $this->file_extensions || '' == $this->cdn_root_url) {
			add_action('admin_notices', array($this, 'settings_warning'));
			return;
		}

		if('/' != $this->cdn_root_url) {
			add_action('template_redirect', array($this, 'start_buffer'), 1);
		}
	}

	/**
	 * get general setting
	 *
	 * @param string $setting setting name
	 * @return mixed setting value or false if not set
	 */
	private function get_setting($setting) {
		$settings = get_option(self::OPTION_GENERAL);
		if(!$settings || !is_array($settings)) {
			$settings = array(
				'file_extensions' => 'bmp|bz2|gif|ico|gz|jpg|jpeg|mp3|pdf|png|rar|rtf|swf|tar|tgz|txt|wav|zip',
				'css_file_extensions' => 'css',
				'js_file_extensions' => 'js'
			);