foo.php

<?php

public static function ShortCodeItemBlocks($arguments, $content = null, $parser = null, $tagname) {
	$page = Controller::curr()->data();
	$itemBlocks = $page->ItemBlocks();
  
	if (isset($arguments['classgroup'])) {
		$itemBlocks = $itemBlocks->filter('ClassGroup', $arguments['classgroup']); 
	}

	$data = ArrayData::create(array(
		'ItemBlocks' => $itemBlocks,
		'Size' => (isset($arguments['size']) ? $arguments['size'] : null,
		'CC' => (isset($arguments['customclass']) ? $arguments['customclass'] : null
	));

	return $data->renderWith(array('ItemBlocks'));
});