org.itsnat.core.event

Interface ItsNatServletRequestListener

public interface ItsNatServletRequestListener

An object implementing this interface and registered is executed to receive and process ItsNat servlet requests usually when a new page is being loaded.

This interface is the ItsNat version of the Servlet.service(ServletRequest,ServletResponse) version. When a client request is received the ItsNat servlet converts and routes this request to the registered ItsNatServletRequestListener objects invoking processRequest(ItsNatServletRequest,ItsNatServletResponse), usually this request is a page load request. This method is not called for events.

A request listener is registered usually calling ItsNatDocumentTemplate.addItsNatServletRequestListener(ItsNatServletRequestListener) and optionally calling ItsNatServlet.addItsNatServletRequestListener(ItsNatServletRequestListener) (for uses like filtering etc).

Another different use is as ItsNat referrer request listener if registered with ItsNatDocument.addReferrerItsNatServletRequestListener(ItsNatServletRequestListener). In this case the listener is called when the framework loads a new target document and the referrer document (the document where the listener was registered) is being unloaded and before the target request listeners are executed (referrer push). Request and response objects are the same objects being sent to the normal target request listeners, target document may be modified, new request attributes may be added etc before ItsNat delegates to the normal target loading process.

Author:

Jose Maria Arranz Santamaria

Method Summary

Methods

Modifier and Type	Method and Description
void	processRequest(ItsNatServletRequest request, ItsNatServletResponse response) If this listener is registered this method is invoked when a client request is received usually for loading a new page.

Method Detail

processRequest

void processRequest(ItsNatServletRequest request,
                  ItsNatServletResponse response)

If this listener is registered this method is invoked when a client request is received usually for loading a new page.

If a new document was requested the ItsNatDocument object is already created using the required template, this document may be obtained calling ItsNatServletRequest.getItsNatDocument() or ItsNatServletResponse.getItsNatDocument(). In this scenario there is no need to use the standard output stream ( ServletResponse.getWriter() or ServletResponse.getOutputStream() ) because ItsNat already uses it behind the scenes. Usual page load request processing involves DOM tree manipulation or custom JavaScript is sent calling ItsNatDocument.addCodeToSend(Object) or ClientDocument.addCodeToSend(Object).

If no new or existing document is requested the request processing is mostly the same as the typical Servlet.service(ServletRequest,ServletResponse) processing including output to standard output stream. This scenario is an opportunity to change the normal ItsNat document request for instance to implement pretty URLs, because the request may be forwarded again to ItsNat calling ItsNatServlet.processRequest(ServletRequest,ServletResponse).

Parameters:

request - the ItsNat request object.

response - the ItsNat response object.