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      <- 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: 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}