org.apache.wicket.request
Interface IRequestMapper

All Known Subinterfaces:

ICompoundRequestMapper

All Known Implementing Classes:

AbstractBookmarkableMapper, AbstractComponentMapper, AbstractMapper, AbstractResourceReferenceMapper, BookmarkableMapper, BufferedResponseMapper, CompoundRequestMapper, CryptoMapper, CustomHomeMapper, HomePageMapper, HttpsMapper, LocaleFirstMapper, MountedMapper, MountMapper, PackageMapper, PageInstanceMapper, ParentPathReferenceRewriter, ResourceMapper, ResourceReferenceMapper, SystemMapper

public interface IRequestMapper

Maps IRequestHandler(s) into Url(s) and Request(s) to IRequestHandler(s). For IRequestHandlers and Requests the implementation doesn't recognize, the mapHandler(IRequestHandler) and mapRequest(Request) methods must return null. The workflow is: the Application class collects a set of IRequestMappers and for each request the request cycle asks these mappers whether any of them knows how to handle the current Request’s url. Wicket pre-configures several mappers which are used for the basic application functionality like a mapper for the home page, a mapper for Wicket resources, for bookmarkable pages, etc. The user application can add additional mappers with the various WebApplication#mountXYZ() methods. The mapper has two main tasks:

1. To create IRequestHandler that will produce the response. When a request comes Wicket uses getCompatibilityScore(Request) to decide which mapper should be asked first to process the request. If two mappers have the same score then the one added later is asked first. This way user’s mappers have precedence than the system ones. If a mapper knows how to handle the request’s url then it should return non-null IRequestHandler.
2. The second task is to produce Url for an IRequestHandler. This is needed at markup rendering time to create the urls for links, forms' action attribute, etc.

Author:

Matej Knopp

Method Summary

int	getCompatibilityScore(Request request) Returns the score representing how compatible this request mapper is to processing the given request.
Url	mapHandler(IRequestHandler requestHandler) Returns the Url for given IRequestHandler or null if the request handler is not recognized.
IRequestHandler	mapRequest(Request request) Returns IRequestHandler for the request or null if the Url is not recognized.

Method Detail

mapRequest

IRequestHandler mapRequest(Request request)

Returns IRequestHandler for the request or null if the Url is not recognized.

Parameters:

request - provides access to request data (i.e. Url and Parameters)

Returns:

RequestHandler instance or null

getCompatibilityScore

int getCompatibilityScore(Request request)

Returns the score representing how compatible this request mapper is to processing the given request. When a request comes in all mappers are scored and are tried in order from highest score to lowest.

A good criteria for calculating the score is the number of matched url segments. For example when there are two mappers for a mounted page, one mapped to /foo another to /foo/bar and the incoming request URL is /foo/bar/baz, the mapping to /foo/bar should probably handle the request first as it has matching segments count of 2 while the first one has only matching segments count of 1.

Note that the method can return value greater then zero even if the mapper does not recognize the request.

Parameters:

request -

Returns:

the compatibility score, e.g. count of matching segments

mapHandler

Url mapHandler(IRequestHandler requestHandler)

Returns the Url for given IRequestHandler or null if the request handler is not recognized.

Parameters:

requestHandler -

Returns:

Url instance or null.