org.apache.taglibs.standard.tag.common.core.RemoveTag Maven / Gradle / Ivy
/*
* Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved.
* 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.common.core;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;
/**
* A handler for the <remove> tag, which removes the variable
* identified by 'var' (and 'scope', if present).
*
* @author Shawn Bayern
*/
public class RemoveTag extends TagSupport {
//*********************************************************************
// Constants
/* We support these 'scopes'. */
private final String APPLICATION = "application";
private final String SESSION = "session";
private final String REQUEST = "request";
private final String PAGE = "page";
//*********************************************************************
// Internal state
private int scope; // tag attribute
private boolean scopeSpecified; // ... by tag attribute
private String var; // tag attribute
//*********************************************************************
// Construction and initialization
/**
* Constructs a new handler. As with TagSupport, subclasses should
* not provide other constructors and are expected to call the
* superclass constructor.
*/
public RemoveTag() {
super();
init();
}
// resets local state
private void init() {
var = null;
scope = PageContext.PAGE_SCOPE;
scopeSpecified = false;
}
// Releases any resources we may have (or inherit)
public void release() {
super.release();
init();
}
//*********************************************************************
// Tag logic
// removes the variable (from a specific scope, if specified)
public int doEndTag() throws JspException {
if (!scopeSpecified)
pageContext.removeAttribute(var);
else
pageContext.removeAttribute(var, scope);
return EVAL_PAGE;
}
//*********************************************************************
// Accessor methods
// for tag attribute
public void setVar(String var) {
this.var = var;
}
// for tag attribute
public void setScope(String scope) {
this.scope = Util.getScope(scope);
scopeSpecified = true;
}
}