org.apache.taglibs.standard.tag.el.xml.ExprTag Maven / Gradle / Ivy
The newest version!
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2008 Sun Microsystems, Inc. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can obtain
* a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
* or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
* Sun designates this particular file as subject to the "Classpath" exception
* as provided by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the License
* Header, with the fields enclosed by brackets [] replaced by your own
* identifying information: "Portions Copyrighted [year]
* [name of copyright owner]"
*
* Contributor(s):
*
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.taglibs.standard.tag.el.xml;
import javax.servlet.jsp.JspException;
import org.apache.taglibs.standard.tag.common.xml.ExprSupport;
import org.apache.taglibs.standard.tag.el.core.ExpressionUtil;
/**
* A handler for <out> that accepts attributes as Strings
* and evaluates them as expressions at runtime.
*
* @author Shawn Bayern
*/
public class ExprTag extends ExprSupport {
//*********************************************************************
// 'Private' state (implementation details)
private String escapeXml_; // stores EL-based property
//*********************************************************************
// Constructor
/**
* Constructs a new handler. As with TagSupport, subclasses
* should not provide other constructors and are expected to call
* the superclass constructor
*/
public ExprTag() {
super();
init();
}
//*********************************************************************
// Tag logic
// evaluates expression and chains to parent
public int doStartTag() throws JspException {
// evaluate any expressions we were passed, once per invocation
evaluateExpressions();
// chain to the parent implementation
return super.doStartTag();
}
// Releases any resources we may have (or inherit)
public void release() {
super.release();
init();
}
//*********************************************************************
// Accessor methods
// for EL-based attribute
public void setEscapeXml(String escapeXml_) {
this.escapeXml_ = escapeXml_;
}
//*********************************************************************
// Private (utility) methods
// (re)initializes state (during release() or construction)
private void init() {
// null implies "no expression"
escapeXml_ = null;
}
/* Evaluates expressions as necessary */
private void evaluateExpressions() throws JspException {
/*
* Note: we don't check for type mismatches here; we assume
* the expression evaluator will return the expected type
* (by virtue of knowledge we give it about what that type is).
* A ClassCastException here is truly unexpected, so we let it
* propagate up.
*/
if (escapeXml_ != null) {
Boolean b = (Boolean) ExpressionUtil.evalNotNull(
"out",
"escapeXml",
escapeXml_,
Boolean.class,
this,
pageContext);
if (b == null)
escapeXml = false;
else
escapeXml = b.booleanValue();
}
}
}