org.sakaiproject.jsf.util.HelperAwareJsfTool.java Source code

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/**********************************************************************************
* $URL:https://source.sakaiproject.org/svn/osp/trunk/common/tool-lib/src/java/org/theospi/portfolio/shared/control/servlet/HelperAwareJsfTool.java $
* $Id:HelperAwareJsfTool.java 9134 2006-05-08 20:28:42Z chmaurer@iupui.edu $
***********************************************************************************
*
 * Copyright (c) 2005, 2006, 2007, 2008 The Sakai Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.jsf.util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.sakaiproject.jsf.util.JsfTool;
import org.sakaiproject.tool.api.ActiveTool;
import org.sakaiproject.tool.api.Tool;
import org.sakaiproject.tool.api.ToolException;
import org.sakaiproject.tool.api.ToolSession;
import org.sakaiproject.tool.cover.ActiveToolManager;
import org.sakaiproject.tool.cover.SessionManager;
import org.sakaiproject.util.Web;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Enumeration;

/**
 * Created by IntelliJ IDEA.
 * User: John Ellis
 * Date: Nov 11, 2005
 * Time: 4:17:18 PM
 * To change this template use File | Settings | File Templates.
 */
public class HelperAwareJsfTool extends JsfTool {

    private static Log M_log = LogFactory.getLog(HelperAwareJsfTool.class);

    private static final String HELPER_EXT = ".helper";

    private static final String HELPER_SESSION_PREFIX = "session.";

    /** the alternate next view */
    public static final String ALTERNATE_DONE_URL = "altDoneURL";

    /** the set of alternate views */
    public static final String ALTERNATE_DONE_URL_MAP = "altDoneURLSet";

    protected void dispatch(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
        // NOTE: this is a simple path dispatching, taking the path as the view id = jsp file name for the view,
        //       with default used if no path and a path prefix as configured.
        // TODO: need to allow other sorts of dispatching, such as pulling out drill-down ids and making them
        //       available to the JSF

        // build up the target that will be dispatched to
        String target = req.getPathInfo();

        // see if we have a helper request
        if (sendToHelper(req, res, target)) {
            return;
        }

        // see if we have a resource request - i.e. a path with an extension, and one that is not the JSF_EXT
        if (isResourceRequest(target)) {
            // get a dispatcher to the path
            RequestDispatcher resourceDispatcher = getServletContext().getRequestDispatcher(target);
            if (resourceDispatcher != null) {
                resourceDispatcher.forward(req, res);
                return;
            }
        }

        if ("Title".equals(req.getParameter("panel"))) {
            // This allows only one Title JSF for each tool
            target = "/title.jsf";
        }

        else {
            ToolSession session = SessionManager.getCurrentToolSession();

            if (target == null || "/".equals(target) || target.length() == 0) {
                if (!m_defaultToLastView) {
                    // make sure tool session is clean
                    session.clearAttributes();
                }

                target = computeDefaultTarget();

                // make sure it's a valid path
                if (!target.startsWith("/")) {
                    target = "/" + target;
                }

                // now that we've messed with the URL, send a redirect to make it official
                res.sendRedirect(Web.returnUrl(req, target));
                return;
            }

            // see if we want to change the specifically requested view
            String newTarget = redirectRequestedTarget(target);

            // make sure it's a valid path
            if (!newTarget.startsWith("/")) {
                newTarget = "/" + newTarget;
            }

            if (!newTarget.equals(target)) {
                // now that we've messed with the URL, send a redirect to make it official
                res.sendRedirect(Web.returnUrl(req, newTarget));
                return;
            }
            target = newTarget;

            // store this
            session.setAttribute(LAST_VIEW_VISITED, target);
        }

        // add the configured folder root and extension (if missing)
        target = m_path + target;

        // add the default JSF extension (if we have no extension)
        int lastSlash = target.lastIndexOf("/");
        int lastDot = target.lastIndexOf(".");
        if (lastDot < 0 || lastDot < lastSlash) {
            target += JSF_EXT;
        }

        // set the information that can be removed from return URLs
        req.setAttribute(URL_PATH, m_path);
        req.setAttribute(URL_EXT, JSF_FACELETS_EXT);

        // set the sakai request object wrappers to provide the native, not Sakai set up, URL information
        // - this assures that the FacesServlet can dispatch to the proper view based on the path info
        req.setAttribute(Tool.NATIVE_URL, Tool.NATIVE_URL);

        // TODO: Should setting the HTTP headers be moved up to the portal level as well?
        res.setContentType("text/html; charset=UTF-8");
        res.addDateHeader("Expires", System.currentTimeMillis() - (1000L * 60L * 60L * 24L * 365L));
        res.addDateHeader("Last-Modified", System.currentTimeMillis());
        res.addHeader("Cache-Control", "no-store, no-cache, must-revalidate, max-age=0, post-check=0, pre-check=0");
        res.addHeader("Pragma", "no-cache");

        // dispatch to the target
        M_log.debug("dispatching path: " + req.getPathInfo() + " to: " + target + " context: "
                + getServletContext().getServletContextName());
        RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(target);
        dispatcher.forward(req, res);

        // restore the request object
        req.removeAttribute(Tool.NATIVE_URL);
        req.removeAttribute(URL_PATH);
        req.removeAttribute(URL_EXT);
    }

    protected boolean sendToHelper(HttpServletRequest req, HttpServletResponse res, String target) {
        String path = req.getPathInfo();
        if (path == null)
            path = "/";

        // 0 parts means the path was just "/", otherwise parts[0] = "", parts[1] = item id, parts[2] if present is "edit"...
        String[] parts = path.split("/");

        if (parts.length < 2) {
            return false;
        }

        if (!parts[1].endsWith(HELPER_EXT)) {
            return false;
        }

        ToolSession toolSession = SessionManager.getCurrentToolSession();

        Enumeration params = req.getParameterNames();
        while (params.hasMoreElements()) {
            String paramName = (String) params.nextElement();
            if (paramName.startsWith(HELPER_SESSION_PREFIX)) {
                String attributeName = paramName.substring(HELPER_SESSION_PREFIX.length());
                toolSession.setAttribute(attributeName, req.getParameter(paramName));
            }
        }

        // calc helper id
        int posEnd = parts[1].lastIndexOf(".");

        String helperId = target.substring(1, posEnd + 1);
        ActiveTool helperTool = ActiveToolManager.getActiveTool(helperId);

        //get the current location (if one doesn't exist) and save it for when we return from the helper
        if (toolSession.getAttribute(helperTool.getId() + Tool.HELPER_DONE_URL) == null
                && !target.equals("/sakai.filepicker.helper")) {
            toolSession.setAttribute(helperTool.getId() + Tool.HELPER_DONE_URL,
                    req.getContextPath() + req.getServletPath() + computeDefaultTarget(true));
        }
        toolSession.setAttribute(helperTool.getId() + "thetoolPath", req.getContextPath() + req.getServletPath());

        // saves the alternate done url map into a tool specific attribute
        if (toolSession.getAttribute(helperTool.getId() + ALTERNATE_DONE_URL) == null) {
            toolSession.setAttribute(helperTool.getId() + ALTERNATE_DONE_URL,
                    toolSession.getAttribute(ALTERNATE_DONE_URL));
            toolSession.setAttribute(helperTool.getId() + ALTERNATE_DONE_URL_MAP,
                    toolSession.getAttribute(ALTERNATE_DONE_URL_MAP));
            toolSession.removeAttribute(ALTERNATE_DONE_URL);
            toolSession.removeAttribute(ALTERNATE_DONE_URL_MAP);
        }

        /*comment out for using the global parameter rather than tool-by-tool setting
            SessionState state = UsageSessionService.getSessionState(toolSession.getPlacementId());
              boolean show_other_sites = ServerConfigurationService.getBoolean("syllabus.resources.show_all_collections.helper", true);
              state.setAttribute("resources.allow_user_to_see_all_sites", (new Boolean(show_other_sites)).toString());
              state.setAttribute("resources.user_chooses_to_see_other_sites", (new Boolean(show_other_sites)).toString());
        */
        String context = req.getContextPath() + req.getServletPath() + Web.makePath(parts, 1, 2);
        String toolPath = Web.makePath(parts, 2, parts.length);
        try {
            helperTool.help(req, res, context, toolPath);
        } catch (ToolException e) {
            throw new RuntimeException(e);
        }

        return true; // was handled as helper call
    }

    protected String computeDefaultTarget(boolean lastVisited) {
        // setup for the default view as configured
        String target = "/" + m_default;

        // if we are doing lastVisit and there's a last-visited view, for this tool placement / user, use that
        if (lastVisited) {
            ToolSession session = SessionManager.getCurrentToolSession();
            String last = (String) session.getAttribute(LAST_VIEW_VISITED);
            if (last != null) {
                target = last;
            }
        }

        return target;
    }
}