Zend Framework应用程序内容转换为xml的插件

在这一篇博文中Thijs Feryn通过实现Zend_Controller_Plugin_Abstract的hook方法，在原程序没有使用context switching控制器助手的情况下，将返回的内容响应转为为特定的XML格式

地址：http://blog.feryn.eu/2009/05/converting-your-zend-framework-mvc-application-into-an-xml-webservice-using-one-single-plugin/

代码： Copy to Clipboard引用的内容：[www.bkjia.com] /**
* My_Plugin_Xml component
* Turns an Zend Framework MVC website into an XML webservice
*  File From Liehuo.Net
*/
/**
* My_Plugin_Xml class
*
* @author Thijs Feryn
*/
class My_Plugin_Xml extends Zend_Controller_Plugin_Abstract
{
/**
* Stores the front controller
*
* @var Zend_Controller_Front
*/
private $_front;
/**
* Stores the XML output in DOMDocument format
*
* @var DOMDocument
*/
private $_xml;
/**
* Class constructor
*/
public function __construct()
{
$this->_front = Zend_Controller_Front::getInstance();
$layout = Zend_Layout::getMvcInstance();
$layout->disableLayout();
}
/**
* Build DOMDocument to convert output to XML
*
* @param mixed $return
* @param Exception $exception
* @return string
*/
private function _getXML($return = null,Exception $exception = null)
{
$this->_xml = new DOMDocument('1.0', 'UTF-8');
$this->_xml->formatOutput = true;

$responseNode = $this->_xml->createElement('response');

$exceptionNode = $this->_xml->createElement('exception');
if(null !== $exception && $exception instanceof Exception ){
$exceptionNode->appendChild(
$this->_xml->createElement('message',
$exception->getMessage()
)
);
$exceptionNode->appendChild(
$this->_xml->createElement('code',
$exception->getCode()
)
);
$exceptionNode->appendChild(
$this->_xml->createElement('type',
get_class($exception)
)
);
}

$responseNode->appendChild($exceptionNode);
if(null !== $return){
$responseNode->appendChild(
$this->_serialize('return',$return)
);
} else {
$responseNode->appendChild(
$this->_xml->createElement('return')
);
}

$this->_xml->appendChild($responseNode);
return $this->_xml->saveXML();
}
/**
* Modify the HTTP response object
* Remove the HTML body, replace with XML and change the content-type
*
* @param mixed $return
* @param Exception $exception
*/
private function _setResponse($return = false,Exception $exception = null)
{
$this->getResponse()->setHeader('Content-Type','text/xml; charset=UTF-8');
$this->getResponse()->clearBody();
$this->getResponse()->setBody(
$this->_getXML($return,$exception)
);
}
/**
* Serialize a mixed value to XML in DOMElement format
* This method can be used recursively in case of objects and arrays
*
* @param string $name
* @param mixed $value
* @return DOMElement
*/
private function _serialize($name,$value)
{
if(is_array($value)){
$element = $this->_xml->createElement($name);
foreach ($value as $k=>$v){
if(is_numeric($k)){
$k = 'item';
}
$element->appendChild($this->_serialize($k,$v));
}
} elseif(is_object($value)){
$element = $this->_xml->createElement($name);
$reflection = new ReflectionObject($value);
$properties = $reflection->getProperties();
foreach ($properties as $property){
if($property->isPublic()){
$element->appendChild(
$this->_serialize(
$property->getName(),
$property->getValue($value)
)
);
}
}
}else{
$element = $this->_xml->createElement(
$name,
(string)$value
);
}
return $element;
}
/**
* preDispatch hook that retrieves if an Exception was thrown in the application
* If an exception is thrown, the exception is passed to the exception part of the XML output and script execution is terminated
*
* @param Zend_Controller_Request_Abstract $request
*/
public function preDispatch(Zend_Controller_Request_Abstract $request)
{
if($this->getResponse()->isException()){
$exArray = $this->getResponse()->getException();
$this->_setResponse(null,$exArray[0]);
$this->getResponse()->sendResponse();
exit();
}
}
/**
* postDispatch hook that serializes the view object to XML by modifying the HTTP response
* If no exception was thrown script execution continues and the postDispatch method will be called
*
* @param Zend_Controller_Request_Abstract $request
*/
public function postDispatch(Zend_Controller_Request_Abstract $request)
{
$view = Zend_Controller_Action_HelperBroker::getExistingHelper('ViewRenderer')->view;
$this->_setResponse($view);
}
}
_getXML()产生特定的xml结构
_setResponse()设置响应的xml内容
_serialize()将返回的对象序列化为xml(使用递归)
preDispatch()判断是否有异常，如果有则只设置异常并终止脚本执行
postDispatch()返回响应

使用方法
$this->_front->registerPlugin(new My_Plugin_Xml());
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