PHP最简单的模板引擎之一

<?php
define('APP_PATH', __DIR__);
class Template{
	private static $_vars;
	private static $_path;
	private static $_prefix;
	private function __construct() {}
	public static function init($path = null) {
		if(isset($path)&&($path!=''))	self::$_path=APP_PATH.'/templates/'.$path.'/';
		else	self::$_path = APP_PATH.'/templates/';
		self::$_vars = array();	
	}
	public static function set_path($path) {
		self::$_path = $path;
	}
	public static function set_prefix($prefix) {
		self::$_prefix = $prefix;
	}
	public static function assign($key, $value = null)
    {	if(!isset(self::$_vars))	self::init();
		if (is_array($key))		self::$_vars = array_merge(self::$_vars,$key);
        elseif (($key != '')&&(isset($value)))		
            self::$_vars[$key] = $value;
    }
	public static function fetch($file) {
		
		if(!isset(self::$_vars))	self::init();
		if(count(self::$_vars)>0)
		{	extract(self::$_vars,EXTR_PREFIX_ALL,self::$_prefix);
			self::$_vars = array();	
		}
		ob_start();
		include self::$_path . $file ;
		$contents = ob_get_contents();
		ob_end_clean();
		self::$_path = null;
		return preg_replace('!\s+!', ' ', $contents);
	}
}
?>