/*
* $Id: ELBaseTag.java 471754 2006-11-06 14:55:09Z husted $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.strutsel.taglib.html;
import org.apache.struts.taglib.html.BaseTag;
import org.apache.strutsel.taglib.utils.EvalHelper;
import javax.servlet.jsp.JspException;
/**
* Renders an HTML <base> element with an href attribute pointing to the
* absolute location of the enclosing JSP page. This tag is only valid when
* nested inside a head tag body. The presence of this tag allows the browser
* to resolve relative URL's to images, CSS stylesheets and other resources
* in a manner independent of the URL used to call the ActionServlet. <p> This
* class is a subclass of the class <code>org.apache.struts.taglib.html.BaseTag</code>
* which provides most of the described functionality. This subclass allows
* all attribute values to be specified as expressions utilizing the
* JavaServer Pages Standard Library expression language.
*
* @version $Rev: 471754 $
*/
public class ELBaseTag extends BaseTag {
/**
* Instance variable mapped to "target" tag attribute. (Mapping set in
* associated BeanInfo class.)
*/
private String targetExpr;
/**
* Instance variable mapped to "server" tag attribute. (Mapping set in
* associated BeanInfo class.)
*/
private String serverExpr;
/**
* Instance variable mapped to "ref" tag attribute. (Mapping set in
* associated BeanInfo class.)
*/
private String refExpr;
/**
* Getter method for "target" tag attribute. (Mapping set in associated
* BeanInfo class.)
*/
public String getTargetExpr() {
return (targetExpr);
}
/**
* Getter method for "server" tag attribute. (Mapping set in associated
* BeanInfo class.)
*/
public String getServerExpr() {
return (serverExpr);
}
/**
* Getter method for "ref" tag attribute. (Mapping set in associated
* BeanInfo class.)
*/
public String getRefExpr() {
return (refExpr);
}
/**
* Setter method for "target" tag attribute. (Mapping set in associated
* BeanInfo class.)
*/
public void setTargetExpr(String targetExpr) {
this.targetExpr = targetExpr;
}
/**
* Setter method for "server" tag attribute. (Mapping set in associated
* BeanInfo class.)
*/
public void setServerExpr(String serverExpr) {
this.serverExpr = serverExpr;
}
/**
* Setter method for "ref" tag attribute. (Mapping set in associated
* BeanInfo class.)
*/
public void setRefExpr(String refExpr) {
this.refExpr = refExpr;
}
/**
* Resets attribute values for tag reuse.
*/
public void release() {
super.release();
setTargetExpr(null);
setServerExpr(null);
setRefExpr(null);
}
/**
* Process the start tag.
*
* @throws JspException if a JSP exception has occurred
*/
public int doStartTag() throws JspException {
evaluateExpressions();
return (super.doStartTag());
}
/**
* Processes all attribute values which use the JSTL expression evaluation
* engine to determine their values.
*
* @throws JspException if a JSP exception has occurred
*/
private void evaluateExpressions()
throws JspException {
String string = null;
if ((string =
EvalHelper.evalString("target", getTargetExpr(), this,
pageContext)) != null) {
setTarget(string);
}
if ((string =
EvalHelper.evalString("server", getServerExpr(), this,
pageContext)) != null) {
setServer(string);
}
if ((string =
EvalHelper.evalString("ref", getRefExpr(), this, pageContext)) != null) {
setRef(string);
}
}
}