Nested SPL objects with recursion.

Blocks.php

<?php

class Layout extends \ArrayIterator
{

}

class Block extends \ArrayIterator
{
    protected $_alias;
    
    public function __construct( $alias = null )
    {
        if( is_null( $alias ) )
        {
            $alias = uniqid( 'Block_' );
        }
    
        $this->_alias = $alias;
    }
    
    public function getAlias()
    {
        return $this->_alias;
    }
}

try
{
    $b1 = new Block( 'Base' );

    $b1_b1 = new Block( 'Base > 1st Child' );

    $b1_b2 = new Block( 'Base > 2nd Child' );

    $b1_b1_b1 = new Block( 'Base > 1st Child > 1st Child' );

    $b1_b1->append( $b1_b1_b1 );

    $b1->append( $b1_b1 );

    $b1->append( $b1_b2 );

    $layout = new Layout;

    $layout->append( $b1 );

    $storage = new \RecursiveIteratorIterator( new \RecursiveArrayIterator( $layout ), RecursiveIteratorIterator::SELF_FIRST );

    foreach( $storage as $key => $value )
    {
        print_r( $value->getAlias() . PHP_EOL );
    }
}
catch( \Exception $e )
{
    var_dump( $e->getMessage() );
}