/*
* $Header: /home/cvs/jakarta-struts/src/tiles-documentation/org/apache/struts/webapp/tiles/portal/UserMenuAction.java,v 1.9 2004/03/14 06:23:52 sraeburn Exp $
* $Revision: 1.9 $
* $Date: 2004/03/14 06:23:52 $
*
* 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.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
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.ComponentDefinition;
import org.apache.struts.tiles.Controller;
import org.apache.struts.tiles.DefinitionsUtil;
import org.apache.struts.tiles.actions.TilesAction;
import org.apache.struts.tiles.beans.MenuItem;
/**
* This controller load user menu settings and put them in tile context.
* If menu settings are not defined for user, defined them based on tiles
* attributes used as default.
*
* This implementation extends Struts Action, and also define Tiles Controller interface.
* This allows to use it as well as a controller type or a controller url. If used
* as controller type, Struts Action functionality are not availables.
*
* 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>title : menu title</li>
* <li>items : Menu items to display</li>
* <li></li>
* </ul>
*
* @version $Revision: 1.9 $ $Date: 2004/03/14 06:23:52 $
*/
public final class UserMenuAction extends TilesAction implements Controller {
/**
* Commons Logging instance.
*/
private static Log log = LogFactory.getLog(UserMenuAction.class);
/**
* Tile attribute containing name used to store user settings in session
* context.
*/
public static String USER_SETTINGS_NAME_ATTRIBUTE = "userSettingsName";
/**
* Default name used to store settings in session context.
*/
public static String DEFAULT_USER_SETTINGS_NAME =
"tiles.examples.portal.USER_MENU_SETTINGS";
/**
* Default name used to store menu catalog in application scope.
*/
public static String DEFAULT_MENU_CATALOG_NAME =
"tiles.examples.portal.MenuCatalog";
/**
* Tile attribute containing name used to store menu catalog in application
* scope.
*/
public static String MENU_CATALOG_NAME_ATTRIBUTE = "catalogName";
/**
* Tile attribute containing name of the settings definition used to
* initialize catalog.
*/
public static final String CATALOG_SETTING_ATTRIBUTE = "catalogSettings";
/**
* Tile attribute containing items to render.
*/
public static String USER_ITEMS_ATTRIBUTE = "items";
/**
* Struts' action perform().
* 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 {
this.execute(
context,
request,
response,
getServlet().getServletContext());
return null;
}
/**
* Method associated to a tile and called immediately before tile is included.
* @param tileContext Current tile context.
* @param request Current request
* @param response Current response
* @param servletContext Current servlet context
*/
public void perform(
ComponentContext context,
HttpServletRequest request,
HttpServletResponse response,
ServletContext servletContext)
throws ServletException, IOException {
log.debug("Enter action UserMenuAction");
// Load user settings from user context
MenuSettings settings = getUserSettings(request, context);
// Set parameters for rendering page
context.putAttribute(USER_ITEMS_ATTRIBUTE, settings.getItems());
log.debug("settings=" + settings);
log.debug("Exit action UserMenuAction");
}
/**
* Load user setting.
* This implementation load setting from user context.
* If settings are not found, initialized them from default items defined
* in Tile's context.
* If settings are not found, initialized them.
*/
public static MenuSettings getUserSettings(
HttpServletRequest request,
ComponentContext context)
throws ServletException {
// Get current session.
HttpSession session = request.getSession();
// Retrieve attribute name used to store settings.
String userSettingsName =
(String) context.getAttribute(USER_SETTINGS_NAME_ATTRIBUTE);
if (userSettingsName == null) {
userSettingsName = DEFAULT_USER_SETTINGS_NAME;
}
// Get user list from user context
MenuSettings settings =
(MenuSettings) session.getAttribute(userSettingsName);
// If settings don't exist, create and initialize them
// Initialization is done from context attribute denoted by ITEMS
if (settings == null) {
// List doesn't exist, create it and initialize it from Tiles parameters
settings = new MenuSettings();
try {
settings.addItems(
(List) context.getAttribute(USER_ITEMS_ATTRIBUTE));
} catch (ClassCastException ex) {
throw new ServletException("Can't initialize user menu : default items must be a list of items");
}
// Save user settings in session
session.setAttribute(userSettingsName, settings);
}
return settings;
}
/**
* Get catalog of available menu entries.
* This implementation creates catalog list from the provided menu bar
* entries.
*/
public static List getCatalog(
ComponentContext context,
HttpServletRequest request,
ServletContext servletContext)
throws ServletException {
// Retrieve name used to store catalog in application context.
// If not found, use default name
String catalogName =
(String) context.getAttribute(MENU_CATALOG_NAME_ATTRIBUTE);
if (catalogName == null) {
catalogName = DEFAULT_MENU_CATALOG_NAME;
}
// Get catalog from context
List catalog = (List) servletContext.getAttribute(catalogName);
// If not found, initialize it from provided default menu
if (catalog == null) {
Object menuBar = context.getAttribute(CATALOG_SETTING_ATTRIBUTE);
if (menuBar == null) {
throw new ServletException(
"Attribute '"
+ CATALOG_SETTING_ATTRIBUTE
+ "' must be set. It define entries used in catalog");
}
catalog = new ArrayList();
extractItems(catalog, menuBar, request, servletContext);
if (catalog.size() == 0) {
throw new ServletException("Can't initialize menu items catalog");
}
// save it for future use
servletContext.setAttribute(catalogName, catalog);
}
return catalog;
}
/**
* Extract menu items from passed object. Items are stored in
* <code>result</code> parameter.
* This method allows to create a list of menu entries from existing menus.
* Check object type class :
* <li>
* <ul>MenuItems : add it</ul>
* <ul>ComponentDefinition : get attribute items, or list if not found.
* Call ExtractItems with resulting attribute.
* </ul>
* <ul>List : iterate on list, and call ExtractItems for each element.
* </li>
* @param result result list (should be initialized)
* @param object object to add (MenuItems, Definition, ...)
* @param request current request
* @param servletContext current servlet context.
*/
private static void extractItems(
List result,
Object object,
HttpServletRequest request,
ServletContext servletContext) {
log.debug("Extract menu item from '" + object + "'");
if (object instanceof String) { // definition name
try {
ComponentDefinition def =
DefinitionsUtil.getDefinition(
(String) object,
request,
servletContext);
extractItems(result, def, request, servletContext);
} catch (Exception ex) { // silently fail
}
} else if (object instanceof List) {
List list = (List) object;
Iterator iter = list.iterator();
while (iter.hasNext()) {
extractItems(result, iter.next(), request, servletContext);
}
} else if (object instanceof ComponentDefinition) {
ComponentDefinition definition = (ComponentDefinition) object;
Object attribute = definition.getAttribute("items");
if (attribute == null) {
attribute = definition.getAttribute("list");
}
if (attribute == null) {
return;
}
extractItems(result, attribute, request, servletContext);
} else if (object instanceof MenuItem) {
result.add(object);
}
}
/**
* @see org.apache.struts.tiles.Controller#execute(org.apache.struts.tiles.ComponentContext, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, javax.servlet.ServletContext)
*/
public void execute(
ComponentContext tileContext,
HttpServletRequest request,
HttpServletResponse response,
ServletContext servletContext)
throws Exception {
log.debug("Enter action UserMenuAction");
// Load user settings from user context
MenuSettings settings = getUserSettings(request, tileContext);
// Set parameters for rendering page
tileContext.putAttribute(USER_ITEMS_ATTRIBUTE, settings.getItems());
log.debug("settings=" + settings);
log.debug("Exit action UserMenuAction");
}
}