001: /*
002: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
003: *
004: * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
005: *
006: * Portions Copyright Apache Software Foundation.
007: *
008: * The contents of this file are subject to the terms of either the GNU
009: * General Public License Version 2 only ("GPL") or the Common Development
010: * and Distribution License("CDDL") (collectively, the "License"). You
011: * may not use this file except in compliance with the License. You can obtain
012: * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
013: * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
014: * language governing permissions and limitations under the License.
015: *
016: * When distributing the software, include this License Header Notice in each
017: * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
018: * Sun designates this particular file as subject to the "Classpath" exception
019: * as provided by Sun in the GPL Version 2 section of the License file that
020: * accompanied this code. If applicable, add the following below the License
021: * Header, with the fields enclosed by brackets [] replaced by your own
022: * identifying information: "Portions Copyrighted [year]
023: * [name of copyright owner]"
024: *
025: * Contributor(s):
026: *
027: * If you wish your version of this file to be governed by only the CDDL or
028: * only the GPL Version 2, indicate your decision by adding "[Contributor]
029: * elects to include this software in this distribution under the [CDDL or GPL
030: * Version 2] license." If you don't indicate a single choice of license, a
031: * recipient has the option to distribute your version of this file under
032: * either the CDDL, the GPL Version 2 or to extend the choice of license to
033: * its licensees as provided above. However, if you add GPL Version 2 code
034: * and therefore, elected the GPL Version 2 license, then the option applies
035: * only if the new code is made subject to such option by the copyright
036: * holder.
037: */
038:
039: package org.apache.taglibs.standard.tag.el.xml;
040:
041: import javax.servlet.jsp.JspException;
042:
043: import org.apache.taglibs.standard.tag.common.xml.ExprSupport;
044: import org.apache.taglibs.standard.tag.el.core.ExpressionUtil;
045:
046: /**
047: * <p>A handler for <out> that accepts attributes as Strings
048: * and evaluates them as expressions at runtime.</p>
049: *
050: * @author Shawn Bayern
051: */
052: public class ExprTag extends ExprSupport {
053:
054: //*********************************************************************
055: // 'Private' state (implementation details)
056:
057: private String escapeXml_; // stores EL-based property
058:
059: //*********************************************************************
060: // Constructor
061:
062: /**
063: * Constructs a new handler. As with TagSupport, subclasses
064: * should not provide other constructors and are expected to call
065: * the superclass constructor
066: */
067: public ExprTag() {
068: super ();
069: init();
070: }
071:
072: //*********************************************************************
073: // Tag logic
074:
075: // evaluates expression and chains to parent
076: public int doStartTag() throws JspException {
077:
078: // evaluate any expressions we were passed, once per invocation
079: evaluateExpressions();
080:
081: // chain to the parent implementation
082: return super .doStartTag();
083: }
084:
085: // Releases any resources we may have (or inherit)
086: public void release() {
087: super .release();
088: init();
089: }
090:
091: //*********************************************************************
092: // Accessor methods
093:
094: // for EL-based attribute
095: public void setEscapeXml(String escapeXml_) {
096: this .escapeXml_ = escapeXml_;
097: }
098:
099: //*********************************************************************
100: // Private (utility) methods
101:
102: // (re)initializes state (during release() or construction)
103: private void init() {
104: // null implies "no expression"
105: escapeXml_ = null;
106: }
107:
108: /* Evaluates expressions as necessary */
109: private void evaluateExpressions() throws JspException {
110: /*
111: * Note: we don't check for type mismatches here; we assume
112: * the expression evaluator will return the expected type
113: * (by virtue of knowledge we give it about what that type is).
114: * A ClassCastException here is truly unexpected, so we let it
115: * propagate up.
116: */
117:
118: if (escapeXml_ != null) {
119: Boolean b = (Boolean) ExpressionUtil.evalNotNull("out",
120: "escapeXml", escapeXml_, Boolean.class, this ,
121: pageContext);
122: if (b == null)
123: escapeXml = false;
124: else
125: escapeXml = b.booleanValue();
126: }
127: }
128: }
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