staging-url-rewrite.php

<?php

if (WP_STAGE == 'production') {
  return;
}

if(!class_exists('WP_Stack_Plugin')){class WP_Stack_Plugin{function hook($h){$p=10;$m=$this->sanitize_method($h);$b=func_get_args();unset($b[0]);foreach((array)$b as $a){if(is_int($a))$p=$a;else $m=$a;}return add_action($h,array($this,$m),$p,999);}private function sanitize_method($m){return str_replace(array('.','-'),array('_DOT_','_DASH_'),$m);}}}

class AVM_Staging_Url_Rewrite extends WP_Stack_Plugin {

	public static $instance;
	public $from = array();
	public $to;

	public function __construct() {
		self::$instance = $this;
		if (!is_admin()) {
			$this->hook('init');
		}
	}

	public function init() {
		$this->hook('template_redirect');
		$this->hook('avm_staging_rewrite', 'rewrite');
		$this->from[]	 = WP_PRODUCTION_HOST;
		$this->to	 = WP_STAGING_HOST;
	}

	public function rewrite($content) {
		$toReplace = (array)$this->from;
		$from	 = $to		 = array();
		foreach ($toReplace as $url) {
			$from[]	 = "='$url";
			$to[]	 = "='$this->to";
			$from[]	 = "=\"$url";
			$to[]	 = "=\"$this->to";
			if (strpos($url, '://www.')) {
				$url	 = str_replace('://www.', '://', $url);
				$from[]	 = "='$url";
				$to[]	 = "='$this->to";
				$from[]	 = "=\"$url";
				$to[]	 = "=\"$this->to";
			}
		}
		return str_replace($from, $to, $content);
	}

	public function template_redirect() {
		ob_start(array($this, 'ob'));
	}

	public function ob($contents) {
		return apply_filters('avm_staging_rewrite', $contents, $this);
	}

}

new AVM_Staging_Url_Rewrite;