org.apache.struts.tiles.commands
Class TilesPreProcessor

java.lang.Object
  org.apache.struts.tiles.commands.TilesPreProcessor

All Implemented Interfaces:

org.apache.commons.chain.Command

public class TilesPreProcessor
extends java.lang.Object
implements org.apache.commons.chain.Command

Command class intended to perform responsibilities of the TilesRequestProcessor in Struts 1.1. Does not actually dispatch requests, but simply prepares the chain context for a later forward as appropriate. Should be added to a chain before something which would handle a conventional ForwardConfig.

This class will never have any effect on the chain unless a TilesDefinitionFactory can be found; however it does not consider the absence of a definition factory to be a fatal error; the command simply returns false and lets the chain continue.

To initialize the TilesDefinitionFactory, use org.apache.struts.chain.commands.legacy.TilesPlugin. This class is a simple extension to org.apache.struts.tiles.TilesPlugin which simply does not interfere with your choice of RequestProcessor implementation.

Field Summary

Fields inherited from interface org.apache.commons.chain.Command

CONTINUE_PROCESSING, PROCESSING_COMPLETE

Constructor Summary

TilesPreProcessor()

Method Summary

protected void	doForward(org.apache.struts.chain.contexts.ServletActionContext context, java.lang.String uri) Do an include of specified URI using a RequestDispatcher.
protected void	doInclude(org.apache.struts.chain.contexts.ServletActionContext context, java.lang.String uri) Do an include of specified URI using a RequestDispatcher.
boolean	execute(org.apache.commons.chain.Context context) If the current ForwardConfig is using "tiles", perform necessary pre-processing to set up the TilesContext and substitute a new ForwardConfig which is understandable to a RequestDispatcher.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TilesPreProcessor

public TilesPreProcessor()

Method Detail

execute

public boolean execute(org.apache.commons.chain.Context context)
                throws java.lang.Exception

If the current ForwardConfig is using "tiles", perform necessary pre-processing to set up the TilesContext and substitute a new ForwardConfig which is understandable to a RequestDispatcher.

Note that if the command finds a previously existing ComponentContext in the request, then it infers that it has been called from within another tile, so instead of changing the ForwardConfig in the chain Context, the command uses RequestDispatcher to include the tile, and returns true, indicating that the processing chain is complete.

Specified by:

execute in interface org.apache.commons.chain.Command

Parameters:

context - The Context for the current request

Returns:

false in most cases, but true if we determine that we're processing in "include" mode.

Throws:

java.lang.Exception

doInclude

protected void doInclude(org.apache.struts.chain.contexts.ServletActionContext context,
                         java.lang.String uri)
                  throws java.io.IOException,
                         javax.servlet.ServletException

Do an include of specified URI using a RequestDispatcher.

Parameters:

context - a chain servlet/web context

uri - Context-relative URI to include

Throws:

java.io.IOException

javax.servlet.ServletException

doForward

protected void doForward(org.apache.struts.chain.contexts.ServletActionContext context,
                         java.lang.String uri)
                  throws java.io.IOException,
                         javax.servlet.ServletException

Do an include of specified URI using a RequestDispatcher.

Parameters:

context - a chain servlet/web context

uri - Context-relative URI to include

Throws:

java.io.IOException

javax.servlet.ServletException