    001package 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
    024import org.apache.turbine.annotation.TurbineService;
    025import org.apache.turbine.pipeline.PipelineData;
    026import org.apache.turbine.services.template.TemplateService;
    027import org.apache.turbine.util.RunData;
    028import org.apache.turbine.util.TurbineException;
    029
    030/**
    031 * When building sites using templates, Screens need only be defined
    032 * for templates which require dynamic (database or object) data.
    033 *
    034 * <p>
    035 *
    036 * This page can be used on sites where the number of Screens can be
    037 * much less than the number of templates.  The templates can be
    038 * grouped in directories with common layouts.  Screen modules are
    039 * then expected to be placed in packages corresponding with the
    040 * templates' directories and follow a specific naming scheme.
    041 *
    042 * <p>
    043 *
    044 * The template parameter is parsed and and a Screen whose package
    045 * matches the templates path and shares the same name minus any
    046 * extension and beginning with a capital letter is searched for.  If
    047 * not found, a Screen in a package matching the template's path with
    048 * name Default is searched for.  If still not found, a Screen with
    049 * name Default is looked for in packages corresponding to parent
    050 * directories in the template's path until a match is found.
    051 *
    052 * <p>
    053 *
    054 * For example if data.getParameters().getString("template") returns
    055 * /about_us/directions/driving.wm, the search follows
    056 * about_us.directions.Driving, about_us.directions.Default,
    057 * about_us.Default, Default, WebMacroSiteScreen (i.e. the default
    058 * screen set in TurbineResources).
    059 *
    060 * <p>
    061 *
    062 * Only one Layout module is used, since it is expected that any
    063 * dynamic content will be placed in navigations and screens.  The
    064 * layout template to be used is found in a similar way to the Screen.
    065 * For example the following paths will be searched in the layouts
    066 * subdirectory: /about_us/directions/driving.wm,
    067 * /about_us/directions/default.wm, /about_us/default.wm, /default.wm,
    068 * where wm is the value of the template.default.extension property.
    069 *
    070 * <p>
    071 *
    072 * This approach allows a site with largely static content to be
    073 * updated and added to regularly by those with little Java
    074 * experience.
    075 *
    076 * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
    077 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
    078 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    079 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
    080 * @version $Id: TemplatePage.java 1695634 2015-08-13 00:35:47Z tv $
    081 */
    082public class TemplatePage
    083    extends DefaultPage
    084{
    085    /** Injected service instance */
    086    @TurbineService
    087    private TemplateService templateService;
    088
    089    /**
    090     * Works with TemplateService to set up default templates and
    091     * corresponding class modules.
    092     *
    093     * @param pipelineData Turbine information.
    094     * @exception Exception, a generic exception.
    095     */
    096    @Override
    097    protected void doBuildAfterAction(PipelineData pipelineData)
    098        throws Exception
    099    {
    100        RunData data = getRunData(pipelineData);
    101        // The Template Service at this point must fetch the Screen class
    102        // to match a given template. If the Screen class has already been
    103        // set by an action, skip this, because the user has the already
    104        // specified the Screen class he wants to use.
    105        if (!data.hasScreen())
    106        {
    107            // This is effectively getting the "template" parameter
    108            // from the parameter parser in rundata. This is coming
    109            // from the request for a template.
    110            String template = data.getTemplateInfo().getScreenTemplate();
    111
    112            // Get the layout template and the correct Screen.
    113            String layoutTemplate =
    114                    templateService.getLayoutTemplateName(template);
    115            data.getTemplateInfo().setLayoutTemplate(layoutTemplate);
    116
    117            String screen = templateService.getScreenName(template);
    118
    119            if (screen == null)
    120            {
    121                String errMsg = "Couldn't map Template "
    122                    + template + " to any Screen class!";
    123                log.error(errMsg);
    124                throw new TurbineException(errMsg);
    125            }
    126            data.setScreen(screen);
    127        }
    128    }
    129}