core-bundle/src/Resources/contao/library/Contao/StringUtil.php
public static function splitCsv($strString, $strDelimiter=',')
	{
		$arrValues = preg_split('/'.$strDelimiter.'(?=(?:[^"]*"[^"]*")*(?![^"]*"))/', $strString);

		foreach ($arrValues as $k=>$v)
		{
			$arrValues[$k] = trim($v, ' "');
		}

		return $arrValues;
	}
public static function splitCsv($strString, $strDelimiter=',')
	{
		$arrValues = preg_split('/'.$strDelimiter.'(?=(?:[^"]*"[^"]*")*(?![^"]*"))/', $strString);

		foreach ($arrValues as $k=>$v)
		{
			$arrValues[$k] = trim($v, ' "');
		}

		return $arrValues;
	}
Split a string of comma separated values

@param string $strString    The string to split
@param string $strDelimiter An optional delimiter

@return array The string chunks