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 is a pretty simple mapper which returns template pathes for
037 * a supplied template name. If the path does not exist, it looks for
038 * a templated called "Default" in the same package.
039 * This path can be used by the TemplateEngine to access
040 * a certain resource to actually render the template.
041 *
042 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
043 * @version $Id$
044 */
045
046public class ScreenDefaultTemplateMapper
047    extends BaseTemplateMapper
048    implements Mapper
049{
050    /** Logging */
051    private static final Logger log = LogManager.getLogger(ScreenDefaultTemplateMapper.class);
052
053    /**
054     * Default C'tor. If you use this C'tor, you must use
055     * the bean setter to set the various properties needed for
056     * this mapper before first usage.
057     */
058    public ScreenDefaultTemplateMapper()
059    {
060        // empty
061    }
062
063    /**
064     * Look for a given Template, then try the
065     * default.
066     *
067     * @param template The template name.
068     * @return The parsed module name.
069     */
070    @Override
071    public String doMapping(String template)
072    {
073        log.debug("doMapping({})", template);
074        // Copy our elements into an array
075        List<String> components
076            = new ArrayList<>(Arrays.asList(StringUtils.split(
077                                              template,
078                                              String.valueOf(TemplateService.TEMPLATE_PARTS_SEPARATOR))));
079        int componentSize = components.size() - 1 ;
080
081        // This method never gets an empty string passed.
082        // So this is never < 0
083        String templateName = components.get(componentSize);
084        components.remove(componentSize--);
085
086        log.debug("templateName is {}", templateName);
087
088        // Last element decides, which template Service to use...
089        TemplateService templateService = (TemplateService)TurbineServices.getInstance().getService(TemplateService.SERVICE_NAME);
090        TemplateEngineService tes = templateService.getTemplateEngineService(templateName);
091
092        if (tes == null)
093        {
094            return null;
095        }
096
097        String defaultName = "Default.vm";
098
099        // This is an optimization. If the name we're looking for is
100        // already the default name for the template, don't do a "first run"
101        // which looks for an exact match.
102        boolean firstRun = !templateName.equals(defaultName);
103
104        for(;;)
105        {
106            String templatePackage = StringUtils.join(components.iterator(), String.valueOf(separator));
107
108            log.debug("templatePackage is now: {}", templatePackage);
109
110            StringBuilder testName = new StringBuilder();
111
112            if (!components.isEmpty())
113            {
114                testName.append(templatePackage);
115                testName.append(separator);
116            }
117
118            testName.append((firstRun)
119                ? templateName
120                : defaultName);
121
122            // But the Templating service must look for the name with prefix
123            StringBuilder templatePath = new StringBuilder();
124            if (StringUtils.isNotEmpty(prefix))
125            {
126                templatePath.append(prefix);
127                templatePath.append(separator);
128            }
129            templatePath.append(testName);
130
131            log.debug("Looking for {}", templatePath);
132
133            if (tes.templateExists(templatePath.toString()))
134            {
135                log.debug("Found it, returning {}", testName);
136                return testName.toString();
137            }
138
139            if (firstRun)
140            {
141                firstRun = false;
142            }
143            else
144            {
145                // We run this loop only two times. The
146                // first time with the 'real' name and the
147                // second time with "Default". The second time
148                // we will end up here and break the for(;;) loop.
149                break;
150            }
151        }
152
153        log.debug("Returning default");
154        return getDefaultName(template);
155    }
156}