<?php
/**
* Zend Framework
*
* LICENSE
*
* This source file is subject to the new BSD license that is bundled
* with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://framework.zend.com/license/new-bsd
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@zend.com so we can send you a copy immediately.
*
* @category Zend
* @package Zend
* @copyright Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
* @version $Id$
*/

/**
* @category Zend
* @package Zend
* @copyright Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
class Zend_Exception extends Exception
{
/**
* @var null|Exception
*/
private $_previous = null;

/**
* Construct the exception
*
* @param string $msg
* @param int $code
* @param Exception $previous
* @return void
*/
public function __construct($msg = '', $code = 0, Exception $previous = null)
{
if (version_compare(PHP_VERSION, '5.3.0', '<')) {
parent::__construct($msg, (int) $code);
$this->_previous = $previous;
} else {
parent::__construct($msg, (int) $code, $previous);
}
}

/**
* Overloading
*
* For PHP < 5.3.0, provides access to the getPrevious() method.
*
* @param string $method
* @param array $args
* @return mixed
*/
public function __call($method, array $args)
{
if ('getprevious' == strtolower($method)) {
return $this->_getPrevious();
}
return null;
}

/**
* String representation of the exception
*
* @return string
*/
public function __toString()
{
if (version_compare(PHP_VERSION, '5.3.0', '<')) {
if (null !== ($e = $this->getPrevious())) {
return $e->__toString()
. "\n\nNext "
. parent::__toString();
}
}
return parent::__toString();
}

/**
* Returns previous Exception
*
* @return Exception|null
*/
protected function _getPrevious()
{
return $this->_previous;
}
}