package org.apache.fulcrum.template;

 /*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you under the Apache License, Version 2.0 (the

  * "License"); you may not use this file except in compliance

  * with the License.  You may obtain a copy of the License at

  *

  *   http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  * KIND, either express or implied.  See the License for the

  * specific language governing permissions and limitations

  * under the License.

  */

 import java.io.File;

 import java.io.OutputStream;

 import java.io.Writer;

 import java.util.ArrayList;

 import java.util.Hashtable;

 import java.util.List;

 import org.apache.avalon.framework.activity.Disposable;

 import org.apache.avalon.framework.configuration.Configurable;

 import org.apache.avalon.framework.configuration.Configuration;

 import org.apache.avalon.framework.configuration.ConfigurationException;

 import org.apache.avalon.framework.context.Context;

 import org.apache.avalon.framework.context.ContextException;

 import org.apache.avalon.framework.context.Contextualizable;

 import org.apache.avalon.framework.logger.AbstractLogEnabled;

 import org.apache.avalon.framework.service.ServiceException;

 import org.apache.avalon.framework.service.ServiceManager;

 import org.apache.avalon.framework.service.Serviceable;

 import org.apache.avalon.framework.thread.ThreadSafe;

 /**

  * The base implementation of Turbine {@link

  * org.apache.fulcrum.template.TemplateEngineService}.

  *

  * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>

  * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>

  * @version $Id: BaseTemplateEngineService.java 535465 2007-05-05 06:58:06Z tv $

  */

 public abstract class BaseTemplateEngineService

     extends AbstractLogEnabled

     implements

         TemplateEngineService,

         Configurable,

         Contextualizable,

         ThreadSafe,

         Disposable,

         Serviceable

 {

     private ServiceManager manager = null;

     /**

      * The application root

      */

     protected String applicationRoot;

     /**

      * A Map containing the configuration for the template

      * engine service. The configuration contains:

      *

      * 1) template extensions

      * 2) default page

      * 3) default screen

      * 4) default layout

      * 5) default navigation

      * 6) default error screen

      */

     private Hashtable configuration = new Hashtable();

     /**

      * @see org.apache.fulcrum.template.TemplateEngineService#getTemplateEngineServiceConfiguration

      */

     public Hashtable getTemplateEngineServiceConfiguration()

     {

         return configuration;

     }

     /**

      * @see org.apache.fulcrum.template.TemplateEngineService#getAssociatedFileExtensions

      */

     public String[] getAssociatedFileExtensions()

     {

         return (String[]) configuration.get(TEMPLATE_EXTENSIONS);

     }

     /**

      * @see org.apache.fulcrum.template.TemplateEngineService#templateExists

      */

     public abstract boolean templateExists(String template);

     public abstract String handleRequest(

         TemplateContext context,

         String template)

         throws TemplateException;

     public abstract void handleRequest(

         TemplateContext context,

         String template,

         OutputStream os)

         throws TemplateException;

     /**

      * @see org.apache.fulcrum.template.TemplateEngineService

      */

     public abstract void handleRequest(

         TemplateContext context,

         String template,

         Writer writer)

         throws TemplateException;

     // ---------------- Avalon Lifecycle Methods ---------------------

     /**

      * Used by subclasses in their configure method

      */

     protected void registerConfiguration(Configuration conf, String defaultExt)

         throws ConfigurationException

     {

         initConfiguration(conf, defaultExt);

         TemplateService component = null;

         try

         {

             component = (TemplateService) manager.lookup(TemplateService.ROLE);

             component.registerTemplateEngineService(this);

         }

         catch (ServiceException ce)

         {

             throw new RuntimeException(ce.getMessage());

         }

         finally

         {

             if (component != null)

             {

                 manager.release(component);

             }

         }

     }

     /**

      * Note engine file extension associations.  First attempts to

      * pull a list of custom extensions from the property file value

      * keyed by <code>template.extension</code>.  If none are defined,

      * uses the value keyed by

      * <code>template.default.extension</code>, defaulting to the

      * emergency value supplied by <code>defaultExt</code>.

      *

      * @param defaultExt The default used when the default defined in the

      *                   properties file is missing or misconfigured.

      */

     private void initConfiguration(Configuration conf, String defaultExt)

         throws ConfigurationException

     {

         List extensionList = new ArrayList();

         final Configuration[] extensions =

             conf.getChildren("template-extension");

         if (extensions != null)

         {

             for (int i = 0; i < extensions.length; i++)

             {

                 extensionList.add(extensions[i].getValue());

             }

         }

         String[] fileExtensionAssociations =

             (String[]) extensionList.toArray(new String[extensionList.size()]);

         if (fileExtensionAssociations == null

             || fileExtensionAssociations.length == 0)

         {

             Configuration defaultConf =

                 conf.getChild("default-template-extension", true);

             fileExtensionAssociations = new String[1];

             fileExtensionAssociations[0] = defaultConf.getValue(defaultExt);

         }

         configuration.put(TEMPLATE_EXTENSIONS, fileExtensionAssociations);

         configuration.put(

             DEFAULT_PAGE_TEMPLATE,

             conf.getChild("default-page-template", true).getValue());

         configuration.put(

             DEFAULT_LAYOUT_TEMPLATE,

             conf.getChild("default-layout-template", true).getValue());

     }

     /**

      * @see org.apache.fulcrum.ServiceBroker#getRealPath(String)

      */

     public String getRealPath(String path)

     {

         String absolutePath = null;

         if (applicationRoot == null)

         {

             absolutePath = new File(path).getAbsolutePath();

         }

         else

         {

             absolutePath = new File(applicationRoot, path).getAbsolutePath();

         }

         return absolutePath;

     }

     // ---------------- Avalon Lifecycle Methods ---------------------

     public void contextualize(Context context) throws ContextException

     {

         this.applicationRoot = context.get("urn:avalon:home").toString();

     }

     /**

      * Avalon component lifecycle method

      */

     public void service(ServiceManager manager) throws ServiceException

     {

         this.manager = manager;

     }

     /**

      * Avalon component lifecycle method

      */

     public void dispose()

     {

         manager = null;

     }

 }