http://stackoverflow.com/questions/8029197/

example.php

<?php

$response = <<<RESP
<Groups>
 <Group>
   <Item>
     <Description>One Item - Color: Black, Size: 9</Description>
   </Item>
  </Group>
  <Group>
    <Item>
      <Description>Two Item - Color: White, Size: 11</Description>
    </Item>
  </Group>
</Groups>
RESP;

$xml = simplexml_load_string($response);
foreach($xml->xpath('Group/Item') as $i => $item)
{
	$description = (string) $item->Description;
	printf("%d: %s\n", $i, $description);
	$item = new Item($description);
	var_dump($item->getName(), $item->getProps());
}

class Item
{
	private $name;
	public function getName()
	{
		return $this->name;
	}
	private $props = array();
	public function getProps()
	{
		return $this->props;
	}
	public function __construct($description)
	{
		$this->initFromText($description);
	}
	private function initFromText($description)
	{
		list($this->name, $propText) = explode(' - ', $description, 2) + array('','');
		
		$propToken = '([a-z]+): (.*?)(, |$)';
		$offset = 0;

		while($r = preg_match("~$propToken~i", $propText, $matches, PREG_OFFSET_CAPTURE, $offset))
		{
			list($full, $name, $value) = $matches;
			if ($full[1] !== $offset || isset($this->props[$name[0]]))
				throw new InvalidArgumentException(sprintf('Invalid Description given ("%s").', $description));
			$this->props[$name[0]] = $value[0];
			$offset += strlen($full[0]);
		}
		// all consumed?
		if (strlen($propText) !== $offset)
			throw new InvalidArgumentException(sprintf('Invalid Description given ("%s").', $description));
	}
}