    001package org.apache.turbine.services.template.mapper;
    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 java.util.ArrayList;
    025import java.util.Arrays;
    026import java.util.List;
    027
    028import org.apache.commons.lang.StringUtils;
    029import org.apache.commons.logging.Log;
    030import org.apache.commons.logging.LogFactory;
    031import org.apache.turbine.services.template.TemplateEngineService;
    032import org.apache.turbine.services.template.TemplateService;
    033import org.apache.turbine.services.template.TurbineTemplate;
    034
    035/**
    036 * This mapper is responsible for the lookup of templates for the Layout
    037 * It tries to look in various packages for a match:
    038 *
    039 * 1. about,directions,Driving.vm      &lt;- exact match
    040 * 2. about,directions,Default.vm      &lt;- package match, Default name
    041 * 3. about,Default.vm                 &lt;- stepping up in the hierarchy
    042 * 4. Default.vm                       &lt;- The name configured as default.layout.template
    043 *                                        in the corresponding Templating Engine
    044
    045 *
    046 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    047 * @version $Id: LayoutTemplateMapper.java 1709648 2015-10-20 17:08:10Z tv $
    048 */
    049
    050public class LayoutTemplateMapper
    051    extends BaseTemplateMapper
    052    implements Mapper
    053{
    054    /** Logging */
    055    private static Log log = LogFactory.getLog(LayoutTemplateMapper.class);
    056
    057    /**
    058     * Default C'tor. If you use this C'tor, you must use
    059     * the bean setter to set the various properties needed for
    060     * this mapper before first usage.
    061     */
    062    public LayoutTemplateMapper()
    063    {
    064        // empty
    065    }
    066
    067    /**
    068     * Look for a given Template, then try the
    069     * defaults until we hit the root.
    070     *
    071     * @param template The template name.
    072     * @return The parsed module name.
    073     */
    074    public String doMapping(String template)
    075    {
    076        log.debug("doMapping(" + template + ")");
    077        // Copy our elements into an array
    078        List<String> components
    079            = new ArrayList<String>(Arrays.asList(StringUtils.split(
    080                                              template,
    081                                              String.valueOf(TemplateService.TEMPLATE_PARTS_SEPARATOR))));
    082        int componentSize = components.size() - 1 ;
    083
    084        // This method never gets an empty string passed.
    085        // So this is never < 0
    086        String templateName = components.get(componentSize);
    087        components.remove(componentSize--);
    088
    089        log.debug("templateName is " + templateName);
    090
    091        // Last element decides, which template Service to use...
    092        TemplateEngineService tes = TurbineTemplate.getTemplateEngineService(templateName);
    093
    094        if (tes == null)
    095        {
    096            return null;
    097        }
    098
    099        String defaultName =
    100            TurbineTemplate.getDefaultLayoutTemplateName(templateName); // We're, after all, a Layout Template Mapper...
    101
    102        // This is an optimization. If the name we're looking for is
    103        // already the default name for the template, don't do a "first run"
    104        // which looks for an exact match.
    105        boolean firstRun = !templateName.equals(defaultName);
    106
    107        for(;;)
    108        {
    109            String templatePackage = StringUtils.join(components.iterator(), String.valueOf(separator));
    110
    111            log.debug("templatePackage is now: " + templatePackage);
    112
    113            StringBuilder testName = new StringBuilder();
    114
    115            if (!components.isEmpty())
    116            {
    117                testName.append(templatePackage);
    118                testName.append(separator);
    119            }
    120
    121            testName.append((firstRun)
    122                ? templateName
    123                : defaultName);
    124
    125            // But the Templating service must look for the name with prefix
    126            StringBuilder templatePath = new StringBuilder();
    127            if (StringUtils.isNotEmpty(prefix))
    128            {
    129                templatePath.append(prefix);
    130                templatePath.append(separator);
    131            }
    132            templatePath.append(testName);
    133
    134            log.debug("Looking for " + templatePath);
    135
    136            if (tes.templateExists(templatePath.toString()))
    137            {
    138                log.debug("Found it, returning " + testName);
    139                return testName.toString();
    140            }
    141
    142            if (firstRun)
    143            {
    144                firstRun = false;
    145            }
    146            else
    147            {
    148                // We're no longer on the first Run (so we
    149                // already tested the "Default" template)
    150                // and the package is empty (we've hit the
    151                // root. So we now break the endless loop.
    152                if (components.isEmpty())
    153                {
    154                    break; // for(;;)
    155                }
    156                // We still have components. Remove the
    157                // last one and go through the loop again.
    158                components.remove(componentSize--);
    159            }
    160        }
    161
    162        log.debug("Returning default");
    163        return getDefaultName(template);
    164    }
    165}