How to create a twig custom tag that executes a callback?

Question

I\'m trying to create a custom Twig tag such as this:

{% mytag \'foo\',\'bar\' %}
   Hello world!!
{% endmytag %}

This tag should print the

Answer 1

After looking at documentation.. Not sure that it follows all the standards, but it works..

require 'Twig/Autoloader.php';
Twig_AutoLoader::register();

class MyTag_TokenParser extends Twig_TokenParser
{
    public function parse(Twig_Token $token)
    {
        $parser = $this->parser;
        $stream = $parser->getStream();

        if (!$stream->test(Twig_Token::BLOCK_END_TYPE))   
           $values = $this->parser->getExpressionParser()
                          ->parseMultitargetExpression();

        $stream->expect(Twig_Token::BLOCK_END_TYPE);

        $body = $this->parser->subparse(array($this, 'decideMyTagEnd'), true);

        $stream->expect(Twig_Token::BLOCK_END_TYPE);

        return new MyTag_Node($body, $values, $token->getLine(), $this->getTag());
    }

    public function decideMyTagEnd(Twig_Token $token)
    {
        return $token->test('endmytag');
    }

    public function getTag()
    {
        return 'mytag';
    }
}

class MyTag_Node extends Twig_Node
{
    public function __construct(Twig_NodeInterface $body, $values,
                                $line, $tag = null)
    {
        if ($values)
           parent::__construct(array('body' => $body, 'values' => $values),
                               array(), $line, $tag);
        else
           parent::__construct(array('body' => $body), array(), $line, $tag);        
    }

    public function compile(Twig_Compiler $compiler)
    {
        $compiler
            ->addDebugInfo($this)
            ->write("ob_start();\n")
            ->subcompile($this->getNode('body'))            
            ->write("my_func(ob_get_clean()");

        if ($this->hasNode('values'))
        foreach ($this->getNode('values') as $node) {
            $compiler->raw(", ")
                     ->subcompile($node);
        };

        $compiler->raw(");\n"); 
    }
}

function my_func()
{
    $args = func_get_args();
    print_r($args);
}

$loader = new Twig_Loader_String();
$twig = new Twig_Environment($loader);
$twig->addTokenParser(new MyTag_TokenParser()); 

$template =<<