/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Blacksmith, Inc.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.web;


/**
* An implementation of WORequestHandler that dispatches Component actions.
*
* @author michael@mpowers.net
* @author $Author: cgruber $
* @version $Revision: 905 $
*/
public class WOComponentRequestHandler
	extends WORequestHandler
{
    public WOResponse handleRequest( WORequest aRequest )
    {
        WOApplication application = aRequest.application();
        WOContext context = WOContext.contextWithRequest( aRequest );
        WOResponse response = null;
            
        // no concurrent access is allowed to a user's session:
        // a user/browser/machine with multiple requests will have to wait
        synchronized ( aRequest.request.getSession() )
        {
            try
            {
                application.awake();
                
                WOSession session = null;
    /*            
                // the NeXT way
                String sessionID = aRequest.sessionID();
                if ( sessionID != null )
                {
                    session = application.restoreSessionWithID( sessionID, context );
                    if ( session == null )
                    {
                        response = application.handleSessionRestorationErrorInContext( context );
                    }
                }
                else
                {
                    session = application.createSessionForRequest( aRequest );
                    if ( session == null )
                    {
                        response = application.handleSessionCreationErrorInContext( context );
                    }
                    else
                    {
                        session.setContext( context );
                    }
                }
    */
                // the servlet way
                String sessionID = aRequest.sessionID();
                if ( sessionID != null )
                {
                    session = application.restoreSessionWithID( sessionID, context );
                }
    
                if ( session == null )
                {
                    session = application.createSessionForRequest( aRequest );
                    if ( session == null )
                    {
                        response = application.handleSessionCreationErrorInContext( context );
                    }
                    else
                    {
                        session.setContext( context );
                    }
                }
                
                context.setSession( session );
                
                session.awake();
                
                if ( response == null )
                {
                    
                    WOComponent page;
                    String contextID = aRequest.contextID(); 
                    
                    if ( contextID != null )
                    {
                        page = session.restorePageForContextID( contextID );
                    }
                    else
                    {
                        page = application.pageWithName( aRequest.pageName(), context ); 
                    }
                    
                    if ( page == null )
                    {
                        //FIXME: should we call this a restoration error, or do we
                        // allow a bookmark with an expired context id to resume gracefully?
                        page = application.pageWithName( aRequest.pageName(), context ); 
                        //!response = application.handlePageRestorationErrorInContext( context );
                    }
                    //!else
                    {
                        context.pushElement( page ); //? needed?
                        page.ensureAwakeInContext( context ); //? shouldn't this be in WOApplication?
    
                        // only take values from request if there are values in the request
                        System.out.println("should I takeValuesFromRequest ? " + ( aRequest.formValueKeys().count() > 0 ));
                        if ( aRequest.formValueKeys().count() > 0 )
                        {
                            application.takeValuesFromRequest( aRequest, context );
                        }
                        
                        // only invoke action if there is a sender id to invoke
                        WOActionResults result;
                        System.out.println("senderID: " + aRequest.senderID());
                        if ( aRequest.senderID() != null )
                        {
                            result = application.invokeAction( aRequest, context );
                        }
                        else
                        {
                            result = null;
                        }
                        
                        if ( result == null || result == page ) // same page is returned
                        {
                            result = page;
                            
                            // generate response
                            response = new WOResponse();
                            application.appendToResponse( response, context );
                            page.sleep();
                        }
                        else // different page is returned
                        if ( result instanceof WOComponent )
                        {
                            page.sleep();
                            page = (WOComponent) result;
                            page.ensureAwakeInContext( context );
                            context.popElement(); // removes page
                            context.pushElement( page );
                            
                            // generate response
                            response = new WOResponse();
                            application.appendToResponse( response, context );
                            page.sleep();
                        }
                        else // WOResponse was returnd
                        {
                            response = (WOResponse) result;
                        }
                        
                        context.popElement();
                        session.sleep();
                        session.savePage( page );
                        session.setContext( null );
                        application.saveSessionForContext( context );
                    }
                }
            }
            catch ( Throwable t )
            {
                response = application.handleException( t, context );
            }
    
            application.sleep();
        }
        return response;
    }
}

/*
 * $Log$
 * Revision 1.2  2006/02/19 01:44:02  cgruber
 * Add xmlrpc files
 * Remove jclark and replace with dom4j and javax.xml.sax stuff
 * Re-work dependencies and imports so it all compiles.
 *
 * Revision 1.1  2006/02/16 13:22:22  cgruber
 * Check in all sources in eclipse-friendly maven-enabled packages.
 *
 * Revision 1.8  2003/08/07 00:15:15  chochos
 * general cleanup (mostly removing unused imports)
 *
 * Revision 1.7  2003/01/17 20:34:57  mpowers
 * Better handling for components and parents in the context's element stack.
 *
 * Revision 1.6  2003/01/15 19:50:49  mpowers
 * Fixed issues with WOSession and Serializable.
 * Can now persist sessions between classloaders (hot swap of class impls).
 *
 * Revision 1.4  2003/01/14 15:51:09  mpowers
 * No longer calling takeValues or invokeAction if there are no request params
 *
 * Revision 1.3  2003/01/13 22:24:34  mpowers
 * Request-response cycle is working with session and page persistence.
 *
 * Revision 1.1  2003/01/09 16:13:59  mpowers
 * Implemented WOComponentRequestHandler:
 * Bringing the request-response cycle more into conformance.
 *
 * Revision 1.2  2002/12/17 14:57:44  mpowers
 * Minor corrections to WORequests's parsing, and updated javadocs.
 *
 * Revision 1.1.1.1  2000/12/21 15:53:19  mpowers
 * Contributing wotonomy.
 *
 * Revision 1.2  2000/12/20 16:25:50  michael
 * Added log to all files.
 *
 *
 */