1 /* 2 * $Id: ELPageTag.java 471754 2006-11-06 14:55:09Z husted $ 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 package org.apache.strutsel.taglib.bean; 22 23 import org.apache.struts.taglib.bean.PageTag; 24 import org.apache.strutsel.taglib.utils.EvalHelper; 25 26 import javax.servlet.jsp.JspException; 27 28 /** 29 * Define a scripting variable that exposes the requested page context item as 30 * a scripting variable and a page scope bean. <p> This class is a subclass of 31 * the class <code>org.apache.struts.taglib.bean.PageTag</code> which provides 32 * most of the described functionality. This subclass allows all attribute 33 * values to be specified as expressions utilizing the JavaServer Pages 34 * Standard Library expression language. 35 * 36 * @version $Rev: 471754 $ 37 */ 38 public class ELPageTag extends PageTag { 39 /** 40 * Instance variable mapped to "id" tag attribute. (Mapping set in 41 * associated BeanInfo class.) 42 */ 43 private String idExpr; 44 45 /** 46 * Instance variable mapped to "property" tag attribute. (Mapping set in 47 * associated BeanInfo class.) 48 */ 49 private String propertyExpr; 50 51 /** 52 * Getter method for "id" tag attribute. (Mapping set in associated 53 * BeanInfo class.) 54 */ 55 public String getIdExpr() { 56 return (idExpr); 57 } 58 59 /** 60 * Getter method for "property" tag attribute. (Mapping set in associated 61 * BeanInfo class.) 62 */ 63 public String getPropertyExpr() { 64 return (propertyExpr); 65 } 66 67 /** 68 * Setter method for "id" tag attribute. (Mapping set in associated 69 * BeanInfo class.) 70 */ 71 public void setIdExpr(String idExpr) { 72 this.idExpr = idExpr; 73 } 74 75 /** 76 * Setter method for "property" tag attribute. (Mapping set in associated 77 * BeanInfo class.) 78 */ 79 public void setPropertyExpr(String propertyExpr) { 80 this.propertyExpr = propertyExpr; 81 } 82 83 /** 84 * Resets attribute values for tag reuse. 85 */ 86 public void release() { 87 super.release(); 88 setIdExpr(null); 89 setPropertyExpr(null); 90 } 91 92 /** 93 * Process the start tag. 94 * 95 * @throws JspException if a JSP exception has occurred 96 */ 97 public int doStartTag() throws JspException { 98 evaluateExpressions(); 99 100 return (super.doStartTag()); 101 } 102 103 /** 104 * Processes all attribute values which use the JSTL expression evaluation 105 * engine to determine their values. 106 * 107 * @throws JspException if a JSP exception has occurred 108 */ 109 private void evaluateExpressions() 110 throws JspException { 111 String string = null; 112 113 if ((string = 114 EvalHelper.evalString("id", getIdExpr(), this, pageContext)) != null) { 115 setId(string); 116 } 117 118 if ((string = 119 EvalHelper.evalString("property", getPropertyExpr(), this, 120 pageContext)) != null) { 121 setProperty(string); 122 } 123 } 124 }