001    package org.apache.turbine.services.template;
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    
024    import java.util.Hashtable;
025    
026    import org.apache.commons.configuration.Configuration;
027    import org.apache.turbine.services.TurbineBaseService;
028    
029    /**
030     * The base implementation of Turbine {@link
031     * org.apache.turbine.services.template.TemplateEngineService}.
032     *
033     * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
034     * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
035     * @version $Id: BaseTemplateEngineService.java 1078552 2011-03-06 19:58:46Z tv $
036     */
037    public abstract class BaseTemplateEngineService
038        extends TurbineBaseService
039        implements TemplateEngineService
040    {
041        /**
042         * A Map containing the configuration for the template
043         * engine service. The configuration contains:
044         *
045         * 1) template extensions
046         * 2) default page
047         * 3) default screen
048         * 4) default layout
049         * 5) default navigation
050         * 6) default error screen
051         */
052        private final Hashtable<String, Object> configuration = new Hashtable<String, Object>();
053    
054        /**
055         * @see org.apache.turbine.services.template.TemplateEngineService#registerConfiguration
056         */
057        public void registerConfiguration(String defaultExt)
058        {
059            initConfiguration(defaultExt);
060            TurbineTemplate.registerTemplateEngineService(this);
061        }
062    
063        /**
064         * @see org.apache.turbine.services.template.TemplateEngineService#getTemplateEngineServiceConfiguration
065         */
066        public Hashtable<String, Object> getTemplateEngineServiceConfiguration()
067        {
068            return configuration;
069        }
070    
071        /**
072         * @see org.apache.turbine.services.template.TemplateEngineService#getAssociatedFileExtensions
073         */
074        public String[] getAssociatedFileExtensions()
075        {
076            return (String[]) configuration.get(TEMPLATE_EXTENSIONS);
077        }
078    
079        /**
080         * Initialize the Template Engine Service.
081         *
082         * Note engine file extension associations.  First attempts to
083         * pull a list of custom extensions from the property file value
084         * keyed by <code>template.extension</code>.  If none are defined,
085         * uses the value keyed by
086         * <code>template.default.extension</code>, defaulting to the
087         * emergency value supplied by <code>defaultExt</code>.
088         *
089         * @param defaultExt The default used when the default defined in the
090         *                   properties file is missing or misconfigured.
091         */
092        protected void initConfiguration(String defaultExt)
093        {
094            Configuration config = getConfiguration();
095    
096            //
097            // Should modify the configuration class to take defaults
098            // here, should have to do this.
099            //
100            String[] fileExtensionAssociations =
101                    config.getStringArray(TEMPLATE_EXTENSIONS);
102    
103            if (fileExtensionAssociations == null ||
104                fileExtensionAssociations.length == 0)
105            {
106                fileExtensionAssociations = new String[1];
107                fileExtensionAssociations[0] = config.getString(
108                        DEFAULT_TEMPLATE_EXTENSION, defaultExt);
109            }
110    
111            configuration.put(TEMPLATE_EXTENSIONS, fileExtensionAssociations);
112    
113            /*
114             * We need some better error checking here and should probably
115             * throw an exception here if these things aren't set
116             * up correctly.
117             */
118    
119            String[] copyParams = {
120                DEFAULT_PAGE,
121                DEFAULT_SCREEN,
122                DEFAULT_LAYOUT,
123                DEFAULT_NAVIGATION,
124                DEFAULT_ERROR_SCREEN,
125                DEFAULT_LAYOUT_TEMPLATE,
126                DEFAULT_SCREEN_TEMPLATE
127            };
128    
129            for (int i = 0; i < copyParams.length; i++)
130            {
131                configuration.put(copyParams[i], config.getString(copyParams[i], ""));
132            }
133        }
134    
135        /**
136         * @see org.apache.turbine.services.template.TemplateEngineService#templateExists
137         */
138        public abstract boolean templateExists(String template);
139    }