struts-sandbox/tiles-documentation/src/java/org/apache/struts/webapp/tiles/portal/UserMenuSettingsAction.java

/*
 * $Id$ 
 *
 * Copyright 1999-2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.struts.webapp.tiles.portal;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.tiles.ComponentContext;
import org.apache.struts.tiles.actions.TilesAction;
import org.apache.struts.tiles.beans.MenuItem;

/**
 * Tiles controller as Struts Action.
 * This controller take a list of lists of MenuItems, and arrange them
 * to be shown by appropriate jsp view.
 * Create and set following attribute in Tile context :
 * <ul>
 *   <li>names : list of names to display</li>
 *   <li>returnedValues : list of corresponding key, or values to return</li>
 *   <li>selecteds : list of boolean indicating whether or not a name is selected</li>
 * </ul>
 * Tiles input attributes :
 * <ul>
 *   <li>title : menu title</li>
 *   <li>items : Menu entries used as default when user settings is created</li>
 *   <li>defaultChoice : Menus or menu entries porposed as choice to user</li>
 *   <li>storeUnderName : Store user settings under provided name in session context [optional]</li>
 *  <li></li>
 * </ul>
 * Tiles output attributes :
 * <ul>
 *   <li>choiceItems : List of menu items proposed as a choice</li>
 *   <li>userItems : List of user actual menu items</li>
 * </ul>
 *
 */
public class UserMenuSettingsAction extends TilesAction {

    /** 
     * Commons Logging instance.
     */
    private static Log log = LogFactory.getLog(UserMenuSettingsAction.class);

    /**
    * Process the specified HTTP request, and create the corresponding HTTP
    * response (or forward to another web component that will create it).
    * Return an <code>ActionForward</code> instance describing where and how
    * control should be forwarded, or <code>null</code> if the response has
    * already been completed.
    *
    * @param context The current Tile context, containing Tile attributes.
    * @param mapping The ActionMapping used to select this instance.
    * @param form The optional ActionForm bean for this request (if any).
    * @param request The HTTP request we are processing.
    * @param response The HTTP response we are creating.
    *
    * @exception Exception if the application business logic throws
    *  an exception
    * @since Struts 1.1
    */
    public ActionForward execute(
        ComponentContext context,
        ActionMapping mapping,
        ActionForm form,
        HttpServletRequest request,
        HttpServletResponse response)
        throws Exception {

        log.debug("Enter action UserMenuSettingsAction");

        MenuSettingsForm actionForm = (MenuSettingsForm) form;

        // Load user menu settings and available list of choices
        MenuSettings settings = UserMenuAction.getUserSettings(request, context);
        List catalog =
            UserMenuAction.getCatalog(
                context,
                request,
                getServlet().getServletContext());

        // Check if form is submitted
        // If true, read, check and store new values submitted by user.
        if (actionForm.isSubmitted()) { // read arrays

            log.debug("form submitted");

            settings.reset();
            settings.addItems(getItems(actionForm.getSelected(), catalog));

            log.debug("settings : " + settings.toString());
            actionForm.reset();

        }

        // Prepare data for view tile
        context.putAttribute("userItems", settings.getItems());
        context.putAttribute("catalog", catalog);

        log.debug("Exit action UserMenuSettingsAction");
        return null;
    }

    /**
     * Check selected items, and return apppropriate list of items.
     * For each item in selected list, check if it exist in catalog.
     * Also check for double.
     * @param selectedKey Key of selected items (generally, link url)
     * @param catalog List of avalaible items to compare against.
     */
    protected static List getItems(String[] selectedKey, List catalog) {
        List selectedList = java.util.Arrays.asList(selectedKey);
        List result = new ArrayList(selectedList.size());

        Iterator iter = selectedList.iterator();
        while (iter.hasNext()) {
            MenuItem item = getItem(iter.next(), catalog);
            if (item != null) {
                result.add(item);
            }
        }
        return result;
    }

    /**
     * Get item by its key in list of choices
     * @param key Key of selected items (generally, link url)
     * @param catalog List of avalaible items to compare against.
     * @return corresponding item or null if not found.
     */
    protected static MenuItem getItem(Object key, List catalog) {
        Iterator iter = catalog.iterator();
        while (iter.hasNext()) {
            MenuItem item = (MenuItem) iter.next();
            if (item.getLink().equals(key)) {
                return item;
            }
        }

        return null;
    }
}