001    package org.apache.turbine.modules.pages;
002    
003    
004    /*
005     * Licensed to the Apache Software Foundation (ASF) under one
006     * or more contributor license agreements.  See the NOTICE file
007     * distributed with this work for additional information
008     * regarding copyright ownership.  The ASF licenses this file
009     * to you under the Apache License, Version 2.0 (the
010     * "License"); you may not use this file except in compliance
011     * with the License.  You may obtain a copy of the License at
012     *
013     *   http://www.apache.org/licenses/LICENSE-2.0
014     *
015     * Unless required by applicable law or agreed to in writing,
016     * software distributed under the License is distributed on an
017     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
018     * KIND, either express or implied.  See the License for the
019     * specific language governing permissions and limitations
020     * under the License.
021     */
022    
023    
024    import org.apache.turbine.pipeline.PipelineData;
025    import org.apache.turbine.services.template.TurbineTemplate;
026    import org.apache.turbine.util.RunData;
027    import org.apache.turbine.util.TurbineException;
028    
029    /**
030     * When building sites using templates, Screens need only be defined
031     * for templates which require dynamic (database or object) data.
032     *
033     * <p>
034     *
035     * This page can be used on sites where the number of Screens can be
036     * much less than the number of templates.  The templates can be
037     * grouped in directories with common layouts.  Screen modules are
038     * then expected to be placed in packages corresponding with the
039     * templates' directories and follow a specific naming scheme.
040     *
041     * <p>
042     *
043     * The template parameter is parsed and and a Screen whose package
044     * matches the templates path and shares the same name minus any
045     * extension and beginning with a capital letter is searched for.  If
046     * not found, a Screen in a package matching the template's path with
047     * name Default is searched for.  If still not found, a Screen with
048     * name Default is looked for in packages corresponding to parent
049     * directories in the template's path until a match is found.
050     *
051     * <p>
052     *
053     * For example if data.getParameters().getString("template") returns
054     * /about_us/directions/driving.wm, the search follows
055     * about_us.directions.Driving, about_us.directions.Default,
056     * about_us.Default, Default, WebMacroSiteScreen (i.e. the default
057     * screen set in TurbineResources).
058     *
059     * <p>
060     *
061     * Only one Layout module is used, since it is expected that any
062     * dynamic content will be placed in navigations and screens.  The
063     * layout template to be used is found in a similar way to the Screen.
064     * For example the following paths will be searched in the layouts
065     * subdirectory: /about_us/directions/driving.wm,
066     * /about_us/directions/default.wm, /about_us/default.wm, /default.wm,
067     * where wm is the value of the template.default.extension property.
068     *
069     * <p>
070     *
071     * This approach allows a site with largely static content to be
072     * updated and added to regularly by those with little Java
073     * experience.
074     *
075     * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
076     * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
077     * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
078     * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
079     * @version $Id: TemplatePage.java 1078552 2011-03-06 19:58:46Z tv $
080     */
081    public class TemplatePage
082        extends DefaultPage
083    {
084        /**
085         * Works with TemplateService to set up default templates and
086         * corresponding class modules.
087         *
088         * @param data Turbine information.
089         * @exception Exception, a generic exception.
090         */
091        @Override
092        protected void doBuildAfterAction(RunData data)
093            throws Exception
094        {
095            // The Template Service at this point must fetch the Screen class
096            // to match a given template. If the Screen class has already been
097            // set by an action, skip this, because the user has the already
098            // specified the Screen class he wants to use.
099            if (!data.hasScreen())
100            {
101                // This is effectively getting the "template" parameter
102                // from the parameter parser in rundata. This is coming
103                // from the request for a template.
104                String template = data.getTemplateInfo().getScreenTemplate();
105    
106                // Get the layout template and the correct Screen.
107                String layoutTemplate =
108                        TurbineTemplate.getLayoutTemplateName(template);
109                data.getTemplateInfo().setLayoutTemplate(layoutTemplate);
110    
111                String screen = TurbineTemplate.getScreenName(template);
112    
113                if (screen == null)
114                {
115                    String errMsg = "Couldn't map Template "
116                        + template + " to any Screen class!";
117                    log.error(errMsg);
118                    throw new TurbineException(errMsg);
119                }
120                data.setScreen(screen);
121            }
122        }
123    
124        /**
125         * Works with TemplateService to set up default templates and
126         * corresponding class modules.
127         *
128         * @param pipelineData Turbine information.
129         * @exception Exception, a generic exception.
130         */
131        @Override
132        protected void doBuildAfterAction(PipelineData pipelineData)
133            throws Exception
134        {
135            RunData data = getRunData(pipelineData);
136            doBuildAfterAction(data);
137        }
138    
139    
140    
141    }