1 package org.apache.turbine.modules; 2 3 4 /* 5 * Licensed to the Apache Software Foundation (ASF) under one 6 * or more contributor license agreements. See the NOTICE file 7 * distributed with this work for additional information 8 * regarding copyright ownership. The ASF licenses this file 9 * to you under the Apache License, Version 2.0 (the 10 * "License"); you may not use this file except in compliance 11 * with the License. You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, 16 * software distributed under the License is distributed on an 17 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 18 * KIND, either express or implied. See the License for the 19 * specific language governing permissions and limitations 20 * under the License. 21 */ 22 23 24 import org.apache.turbine.pipeline.PipelineData; 25 import org.apache.turbine.util.RunData; 26 27 /** 28 * This is the interface which defines the Screen modules. 29 * 30 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a> 31 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> 32 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a> 33 * @version $Id: Screen.java 1854797 2019-03-04 20:41:39Z tv $ 34 */ 35 @FunctionalInterface 36 public interface Screen extends Assembler 37 { 38 /** Prefix for screen related classes and templates */ 39 String PREFIX = "screens"; 40 41 /** Property for the size of the screen cache if caching is on */ 42 String CACHE_SIZE_KEY = "screen.cache.size"; 43 44 /** The default size for the screen cache */ 45 int CACHE_SIZE_DEFAULT = 50; 46 47 /** Represents Screen Objects */ 48 String NAME = "screen"; 49 50 /** 51 * A subclass must implement this method to build itself. 52 * Subclasses override this method to store the screen in RunData 53 * or to write the screen to the output stream referenced in 54 * RunData. 55 * @param pipelineData Turbine information. 56 * @return the content of the screen 57 * @throws Exception a generic exception. 58 */ 59 String doBuild(PipelineData pipelineData) throws Exception; 60 61 /** 62 * Subclasses can override this method to add additional 63 * functionality. 64 * 65 * @param pipelineData Turbine information. 66 * @return the content of the screen 67 * @throws Exception a generic exception. 68 */ 69 default String build(PipelineData pipelineData) 70 throws Exception 71 { 72 return doBuild(pipelineData); 73 } 74 75 /** 76 * If the Layout has not been defined by the Screen then set the 77 * layout to be "DefaultLayout". The Screen object can also 78 * override this method to provide intelligent determination of 79 * the Layout to execute. You can also define that logic here as 80 * well if you want it to apply on a global scale. For example, 81 * if you wanted to allow someone to define Layout "preferences" 82 * where they could dynamically change the Layout for the entire 83 * site. The information for the request is passed in with the 84 * PipelineData object. 85 * 86 * @param pipelineData Turbine information. 87 * @return A String with the Layout. 88 */ 89 default String getLayout(PipelineData pipelineData) 90 { 91 RunData data = pipelineData.getRunData(); 92 return data.getLayout(); 93 } 94 95 /** 96 * Set the layout for a Screen. 97 * 98 * @param pipelineData Turbine information. 99 * @param layout The layout name. 100 */ 101 default void setLayout(PipelineData pipelineData, String layout) 102 { 103 RunData data = pipelineData.getRunData(); 104 data.setLayout(layout); 105 } 106 }