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.lang3.StringUtils;
029import org.apache.logging.log4j.LogManager;
030import org.apache.logging.log4j.Logger;
031import org.apache.turbine.services.TurbineServices;
032import org.apache.turbine.services.template.TemplateEngineService;
033import org.apache.turbine.services.template.TemplateService;
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      <- exact match
040 * 2. about,directions,Default.vm      <- package match, Default name
041 * 3. about,Default.vm                 <- stepping up in the hierarchy
042 * 4. Default.vm                       <- 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 $Id$
048 */
049
050public class LayoutTemplateMapper
051    extends BaseTemplateMapper
052    implements Mapper
053{
054    /** Logging */
055    private static final Logger log = LogManager.getLogger(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    @Override
075    public String doMapping(String template)
076    {
077        log.debug("doMapping({})", template);
078        // Copy our elements into an array
079        List<String> components
080            = new ArrayList<>(Arrays.asList(StringUtils.split(
081                                              template,
082                                              String.valueOf(TemplateService.TEMPLATE_PARTS_SEPARATOR))));
083        int componentSize = components.size() - 1 ;
084
085        // This method never gets an empty string passed.
086        // So this is never < 0
087        String templateName = components.get(componentSize);
088        components.remove(componentSize--);
089
090        log.debug("templateName is {}", templateName);
091
092        // Last element decides, which template Service to use...
093        TemplateService templateService = (TemplateService)TurbineServices.getInstance().getService(TemplateService.SERVICE_NAME);
094        TemplateEngineService tes = templateService.getTemplateEngineService(templateName);
095
096        if (tes == null)
097        {
098            return null;
099        }
100
101        // We're, after all, a Layout Template Mapper...
102        String defaultName = templateService.getDefaultLayoutTemplateName(templateName);
103
104        // This is an optimization. If the name we're looking for is
105        // already the default name for the template, don't do a "first run"
106        // which looks for an exact match.
107        boolean firstRun = !templateName.equals(defaultName);
108
109        for(;;)
110        {
111            String templatePackage = StringUtils.join(components.iterator(), String.valueOf(separator));
112
113            log.debug("templatePackage is now: {}", templatePackage);
114
115            StringBuilder testName = new StringBuilder();
116
117            if (!components.isEmpty())
118            {
119                testName.append(templatePackage);
120                testName.append(separator);
121            }
122
123            testName.append((firstRun)
124                ? templateName
125                : defaultName);
126
127            // But the Templating service must look for the name with prefix
128            StringBuilder templatePath = new StringBuilder();
129            if (StringUtils.isNotEmpty(prefix))
130            {
131                templatePath.append(prefix);
132                templatePath.append(separator);
133            }
134            templatePath.append(testName);
135
136            log.debug("Looking for {}", templatePath);
137
138            if (tes.templateExists(templatePath.toString()))
139            {
140                log.debug("Found it, returning {}", testName);
141                return testName.toString();
142            }
143
144            if (firstRun)
145            {
146                firstRun = false;
147            }
148            else
149            {
150                // We're no longer on the first Run (so we
151                // already tested the "Default" template)
152                // and the package is empty (we've hit the
153                // root. So we now break the endless loop.
154                if (components.isEmpty())
155                {
156                    break; // for(;;)
157                }
158                // We still have components. Remove the
159                // last one and go through the loop again.
160                components.remove(componentSize--);
161            }
162        }
163
164        log.debug("Returning default");
165        return getDefaultName(template);
166    }
167}