From http://query7.com/php-twig-template-wrapper

php-twig-template-wrapper.php

<?php

class Template
{

	public $context = array();

	private $template;

	public function __construct($template)
	{		

		$loader = new Twig_Loader_Filesystem(Settings::get('template_directories'));

		$twig = new Twig_Environment($loader, array(

			'cache' => Settings::get('template_cache_directory'),
			'debug' => Settings::get('debug'),

				)

		);

		$this->template = $twig->loadTemplate($template);

	}

	public function setContext(array $context = array())
	{
		$this->context = array_merge($context, $this->context);

	}

	public function render()
	{
		return $this->template->render($this->context);
	}	

	public function __toString()
	{
		return $this->render();
	}

	public function __set($key, $val)
	{
		$this->context[$key] = $val;
	}

	public function __get($key)
	{
		return $this->context[$key];
	}

}