001package 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
024import java.util.Hashtable;
025
026import org.apache.commons.configuration.Configuration;
027import 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 */
037public 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}