1 package org.apache.turbine.modules; 2 3 /* 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 22 import org.apache.turbine.Turbine; 23 import org.apache.turbine.pipeline.PipelineData; 24 25 /** 26 * The purpose of this class is to allow one to load and execute 27 * Navigation modules. 28 * 29 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a> 30 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> 31 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a> 32 * @version $Id: NavigationLoader.java 1854786 2019-03-04 18:29:18Z tv $ 33 */ 34 public class NavigationLoader 35 extends GenericLoader<Navigation> 36 { 37 /** The single instance of this class. */ 38 private static NavigationLoaderder.html#NavigationLoader">NavigationLoader instance = new NavigationLoader(); 39 40 /** 41 * These ctor's are private to force clients to use getInstance() 42 * to access this class. 43 */ 44 private NavigationLoader() 45 { 46 super(Navigation.class, 47 () -> Turbine.getConfiguration().getInt(Navigation.CACHE_SIZE_KEY, 48 Navigation.CACHE_SIZE_DEFAULT)); 49 } 50 51 /** 52 * Attempts to load and execute the external Navigation. This is 53 * used when you want to execute a Navigation which returns its 54 * output via a MultiPartElement instead of out the data.getPage() 55 * value. This allows you to easily chain the execution of 56 * Navigation modules together. 57 * 58 * @param pipelineData Turbine information. 59 * @param name Name of object that will execute the navigation. 60 * @return the navigation module output 61 * @throws Exception a generic exception. 62 */ 63 public String eval(PipelineData pipelineData, String name) 64 throws Exception 65 { 66 // Execute Navigation 67 return getAssembler(name).build(pipelineData); 68 } 69 70 /** 71 * Attempts to load and execute the external Navigation. 72 * 73 * @param pipelineData Turbine information. 74 * @param name Name of object instance. 75 * @throws Exception a generic exception. 76 */ 77 @Override 78 public void exec(PipelineData pipelineData, String name) 79 throws Exception 80 { 81 this.eval(pipelineData, name); 82 } 83 84 /** 85 * The method through which this class is accessed. 86 * 87 * @return The single instance of this class. 88 */ 89 public static NavigationLoader getInstance() 90 { 91 return instance; 92 } 93 }