package org.appfuse.webapp.action;

import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.tiles.ComponentContext;
import org.apache.struts.tiles.ControllerSupport;
import org.appfuse.webapp.listener.UserCounterListener;


/**
 * UserCounterController class.  This class is used to display the
 * number of current users on a particular tile (JSP page).
 *
 * <p>
 * <a href="UserCounterController.java.html"><i>View Source</i></a>
 * </p>
 *
 * @author <a href="mailto:matt@raibledesigns.com">Matt Raible</a>
 * @version $Revision: 1.4 $ $Date: 2004/03/31 13:04:24 $
 */
public final class UserCounterController extends ControllerSupport {
    //~ Methods ================================================================

    /**
     * This method illustrates a simple example of using a Tiles Controller
     * to get a "current users" counter for this application.
     *
     * @param tilesContext Current tile context
     * @param request Current request
     * @param response Current response
     * @param servletContext Current Servlet Context
     *
     * @throws ServletException DOCUMENT ME!
     * @throws IOException DOCUMENT ME!
     */
    public void execute(ComponentContext tilesContext,
                        HttpServletRequest request,
                        HttpServletResponse response,
                        ServletContext servletContext)
    throws ServletException, IOException {
        // Get the number of current users from the application's context
        String userCounter =
            (String) servletContext.getAttribute(UserCounterListener.COUNT_KEY);

        // Add this number to the request for display
        request.setAttribute(UserCounterListener.COUNT_KEY, userCounter);
    }
}