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.ecs.ConcreteElement; 23 import org.apache.turbine.Turbine; 24 import org.apache.turbine.pipeline.PipelineData; 25 import org.apache.turbine.util.RunData; 26 27 /** 28 * The purpose of this class is to allow one to load and execute 29 * Navigation modules. 30 * 31 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a> 32 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> 33 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a> 34 * @version $Id: NavigationLoader.java 1078552 2011-03-06 19:58:46Z tv $ 35 */ 36 public class NavigationLoader 37 extends GenericLoader<Navigation> 38 implements Loader<Navigation> 39 { 40 /** The single instance of this class. */ 41 private static NavigationLoader instance = new NavigationLoader(); 42 43 /** 44 * These ctor's are private to force clients to use getInstance() 45 * to access this class. 46 */ 47 private NavigationLoader() 48 { 49 super(); 50 } 51 52 /** 53 * Attempts to load and execute the external Navigation. This is 54 * used when you want to execute a Navigation which returns its 55 * output via a MultiPartElement instead of out the data.getPage() 56 * value. This allows you to easily chain the execution of 57 * Navigation modules together. 58 * 59 * @deprecated Use PipelineData version instead. 60 * @param data Turbine information. 61 * @param name Name of object that will execute the navigation. 62 * @exception Exception a generic exception. 63 */ 64 @Deprecated 65 public ConcreteElement eval(RunData data, String name) 66 throws Exception 67 { 68 // Execute Navigation 69 return getAssembler(name).build(data); 70 } 71 72 /** 73 * Attempts to load and execute the external Navigation. This is 74 * used when you want to execute a Navigation which returns its 75 * output via a MultiPartElement instead of out the data.getPage() 76 * value. This allows you to easily chain the execution of 77 * Navigation modules together. 78 * 79 * @param data Turbine information. 80 * @param name Name of object that will execute the navigation. 81 * @exception Exception a generic exception. 82 */ 83 public ConcreteElement eval(PipelineData pipelineData, String name) 84 throws Exception 85 { 86 // Execute Navigation 87 return getAssembler(name).build(pipelineData); 88 } 89 90 91 /** 92 * Attempts to load and execute the external Navigation. 93 * @deprecated Use PipelineData version instead. 94 * @param data Turbine information. 95 * @param name Name of object instance. 96 * @exception Exception a generic exception. 97 */ 98 @Deprecated 99 @Override 100 public void exec(RunData data, String name) 101 throws Exception 102 { 103 this.eval(data, name); 104 } 105 106 /** 107 * Attempts to load and execute the external Navigation. 108 * 109 * @param pipelineData Turbine information. 110 * @param name Name of object instance. 111 * @exception Exception a generic exception. 112 */ 113 @Override 114 public void exec(PipelineData pipelineData, String name) 115 throws Exception 116 { 117 this.eval(pipelineData, name); 118 } 119 120 121 /** 122 * Pulls out an instance of the object by name. Name is just the 123 * single name of the object. This is equal to getInstance but 124 * returns an Assembler object and is needed to fulfil the Loader 125 * interface. 126 * 127 * @param name Name of object instance. 128 * @return A Layout with the specified name, or null. 129 * @exception Exception a generic exception. 130 */ 131 public Navigation getAssembler(String name) 132 throws Exception 133 { 134 return getAssembler(Navigation.NAME, name); 135 } 136 137 /** 138 * @see org.apache.turbine.modules.Loader#getCacheSize() 139 */ 140 public int getCacheSize() 141 { 142 return NavigationLoader.getConfiguredCacheSize(); 143 } 144 145 /** 146 * The method through which this class is accessed. 147 * 148 * @return The single instance of this class. 149 */ 150 public static NavigationLoader getInstance() 151 { 152 return instance; 153 } 154 155 /** 156 * Helper method to get the configured cache size for this module 157 * 158 * @return the configure cache size 159 */ 160 private static int getConfiguredCacheSize() 161 { 162 return Turbine.getConfiguration().getInt(Navigation.CACHE_SIZE_KEY, 163 Navigation.CACHE_SIZE_DEFAULT); 164 } 165 }