org.apache.wicket.request
Interface IRequestCycleProcessor

All Known Implementing Classes:

AbstractRequestCycleProcessor, UrlCompressingWebRequestProcessor, WebRequestCycleProcessor

public interface IRequestCycleProcessor

The request cycle processor is responsible for handling the steps of a request cycle. It's methods are called in a pre-defined order:

• resolve(RequestCycle, RequestParameters) is called to get the request target. A request might refer to e.g. a bookmarkable page, a listener interface call on a component on a previously rendered page, a shared resource or e.g. a non-wicket resource that resides in the web application folder.
• processEvents(RequestCycle) is called after the target is resolved. It is meant to handle/ distribute events like e.g. listener interface calls on components. During this processing, the request target may be changed (e.g. by calling setResponsePage). What actually happens is that RequestCycle holds a stack of targets, of which it will take to last addition as the recent one, but walks the whole stack in order to do cleaning up after the request is handled.
• respond(RequestCycle) is called to create a response to the requesting client. Typically, the actual response handling is to be (or delegated) by the request target implementation, but different strategies might do as they seem fit.
• respond(RuntimeException, RequestCycle) is called whenever an uncaught exception occurs during the event handling or response phase so that an appropriate exception response can be generated. This method is guaranteed to be called whenever such an exception happens, but will never be called otherwise.

Author:

hillenius

See Also:

AbstractRequestCycleProcessor, WebRequestCycleProcessor

Method Summary

IRequestCodingStrategy	getRequestCodingStrategy() Gets the object that is responsible for encoding request targets (like url's in links etc) and decoding urls and request parameters etc into RequestParameters objects.
void	processEvents(RequestCycle requestCycle) After a page is restored, this method is responsible for calling any event handling code based on the request.
IRequestTarget	resolve(RequestCycle requestCycle, RequestParameters requestParameters) Resolves the request and returns the request target.
void	respond(RequestCycle requestCycle) After the target is resolved and the request events are handled, it is time to respond to the request.
void	respond(java.lang.RuntimeException e, RequestCycle requestCycle) Whenever a unhandled exception is encountered during the processing of a request cycle, this method is called to respond to the request in a proper way.

Method Detail

getRequestCodingStrategy

IRequestCodingStrategy getRequestCodingStrategy()

Gets the object that is responsible for encoding request targets (like url's in links etc) and decoding urls and request parameters etc into RequestParameters objects.

Returns:

the request encoder

resolve

IRequestTarget resolve(RequestCycle requestCycle,
                       RequestParameters requestParameters)

Resolves the request and returns the request target. Typically, the resolver uses the RequestParameters object that is passed in.

Implementors of this method should be careful not to mix this code with event handling code; method processEvents(RequestCycle) is meant for that purpose.

Parameters:

requestCycle - the current request cycle

requestParameters - The request parameters object as decoded by this processor's IRequestCodingStrategy.

Returns:

the request target; has to be non-null!

processEvents

void processEvents(RequestCycle requestCycle)

After a page is restored, this method is responsible for calling any event handling code based on the request. For example, when a link is clicked, resolve(RequestCycle, RequestParameters) should return the page that that link resides on, and this method should call the ILinkListener interface on that component.

Parameters:

requestCycle - the current request cycle

respond

void respond(RequestCycle requestCycle)

After the target is resolved and the request events are handled, it is time to respond to the request. This method is responsible for executing the proper response sequence given the current request target and response.

Parameters:

requestCycle - the current request cycle

respond

void respond(java.lang.RuntimeException e,
             RequestCycle requestCycle)

Whenever a unhandled exception is encountered during the processing of a request cycle, this method is called to respond to the request in a proper way.

Parameters:

e - any unhandled exception

requestCycle - the current request cycle