    001package org.apache.turbine.modules;
    002
    003/*
    004 * Licensed to the Apache Software Foundation (ASF) under one
    005 * or more contributor license agreements.  See the NOTICE file
    006 * distributed with this work for additional information
    007 * regarding copyright ownership.  The ASF licenses this file
    008 * to you under the Apache License, Version 2.0 (the
    009 * "License"); you may not use this file except in compliance
    010 * with the License.  You may obtain a copy of the License at
    011 *
    012 *   http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing,
    015 * software distributed under the License is distributed on an
    016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    017 * KIND, either express or implied.  See the License for the
    018 * specific language governing permissions and limitations
    019 * under the License.
    020 */
    021
    022import org.apache.turbine.Turbine;
    023import org.apache.turbine.pipeline.PipelineData;
    024
    025/**
    026 * The purpose of this class is to allow one to load and execute
    027 * Layout modules.
    028 *
    029 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
    030 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    031 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
    032 * @version $Id: LayoutLoader.java 1695634 2015-08-13 00:35:47Z tv $
    033 */
    034public class LayoutLoader
    035    extends GenericLoader<Layout>
    036    implements Loader<Layout>
    037{
    038    /** The single instance of this class. */
    039    private static LayoutLoader instance = new LayoutLoader();
    040
    041    /**
    042     * These ctor's are private to force clients to use getInstance()
    043     * to access this class.
    044     */
    045    private LayoutLoader()
    046    {
    047        super();
    048    }
    049
    050    /**
    051     * Attempts to load and execute the external layout.
    052     *
    053     * @param pipelineData Turbine information.
    054     * @param name Name of object that will execute the layout.
    055     * @exception Exception a generic exception.
    056     */
    057    @Override
    058    public void exec(PipelineData pipelineData, String name)
    059                throws Exception
    060    {
    061        getAssembler(name).build(pipelineData);
    062    }
    063
    064    /**
    065     * Pulls out an instance of the object by name.  Name is just the
    066     * single name of the object.
    067     *
    068     * @param name Name of object instance.
    069     * @return A Layout with the specified name, or null.
    070     * @exception Exception a generic exception.
    071     */
    072    @Override
    073    public Layout getAssembler(String name)
    074        throws Exception
    075    {
    076        return getAssembler(Layout.class, name);
    077    }
    078
    079    /**
    080     * @see org.apache.turbine.modules.Loader#getCacheSize()
    081     */
    082    @Override
    083    public int getCacheSize()
    084    {
    085        return LayoutLoader.getConfiguredCacheSize();
    086    }
    087
    088    /**
    089     * The method through which this class is accessed.
    090     *
    091     * @return The single instance of this class.
    092     */
    093    public static LayoutLoader getInstance()
    094    {
    095        return instance;
    096    }
    097
    098    /**
    099     * Helper method to get the configured cache size for this module
    100     *
    101     * @return the configure cache size
    102     */
    103    private static int getConfiguredCacheSize()
    104    {
    105        return Turbine.getConfiguration().getInt(Layout.CACHE_SIZE_KEY,
    106                Layout.CACHE_SIZE_DEFAULT);
    107    }
    108}