package org.apache.turbine.modules.layouts;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache Turbine" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* "Apache Turbine", nor may "Apache" appear in their name, without
* prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import java.io.StringReader;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.ecs.ConcreteElement;
import org.apache.turbine.TurbineConstants;
import org.apache.turbine.modules.Layout;
import org.apache.turbine.modules.ScreenLoader;
import org.apache.turbine.services.velocity.TurbineVelocity;
import org.apache.turbine.services.xslt.TurbineXSLT;
import org.apache.turbine.util.RunData;
import org.apache.turbine.util.template.TemplateNavigation;
import org.apache.velocity.context.Context;
/**
* This Layout module allows Velocity XML templates to be used as layouts.
* <br><br>
* Once the (XML) screen and navigation templates have been inserted into
* the layout template the result is transformed with a XSL stylesheet.
* The stylesheet (with the same name than the screen template) is loaded
* and executed by the XSLT service, so it is important that you correctly
* set up your XSLT service. If the named stylsheet does not exist the
* default.xsl stylesheet is executed. If default.xsl does not exist
* the XML is merely echoed.
* <br><br>
* Since dynamic content is supposed to be primarily located in
* screens and navigations there should be relatively few reasons to
* subclass this Layout.
*
* @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a>
* @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
* @version $Id: VelocityXslLayout.java,v 1.9 2003/04/11 14:07:08 henning Exp $
*/
public class VelocityXslLayout extends Layout
{
/** Logging */
private static Log log = LogFactory.getLog(VelocityXslLayout.class);
/** The prefix for lookup up layout pages */
private String prefix = TurbineConstants.LAYOUT_PREFIX + "/";
/**
* Build the layout. Also sets the ContentType and Locale headers
* of the HttpServletResponse object.
*
* @param data Turbine information.
* @exception Exception a generic exception.
*/
public void doBuild(RunData data)
throws Exception
{
// Get the context needed by Velocity.
Context context = TurbineVelocity.getContext(data);
data.getResponse().setContentType("text/html");
String screenName = data.getScreen();
log.debug("Loading Screen " + screenName);
// First, generate the screen and put it in the context so
// we can grab it the layout template.
ConcreteElement results =
ScreenLoader.getInstance().eval(data, screenName);
String returnValue = (results == null) ? "" : results.toString();
// variable for the screen in the layout template
context.put(TurbineConstants.SCREEN_PLACEHOLDER, returnValue);
// variable to reference the navigation screen in the layout template
context.put(TurbineConstants.NAVIGATION_PLACEHOLDER,
new TemplateNavigation(data));
// Grab the layout template set in the VelocityPage.
// If null, then use the default layout template
// (done by the TemplateInfo object)
String templateName = data.getTemplateInfo().getLayoutTemplate();
log.debug("Now trying to render layout " + templateName);
// Now, generate the layout template.
String temp = TurbineVelocity.handleRequest(context,
prefix + templateName);
// Finally we do a transformation and send the result
// back to the browser
TurbineXSLT.transform(
data.getTemplateInfo().getScreenTemplate(),
new StringReader(temp), data.getOut());
}
}