org.apache.commons.jexl.parser.ASTEmptyFunction Maven / Gradle / Ivy
/*
* 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.commons.jexl.parser;
import org.apache.commons.jexl.JexlContext;
import java.util.Collection;
import java.util.Map;
/**
* function to see if reference doesn't exist in context.
*
* @author Geir Magnusson Jr.
* @author Tim O'Brien
* @version $Id: ASTEmptyFunction.java 480412 2006-11-29 05:11:23Z bayard $
*/
public class ASTEmptyFunction extends SimpleNode {
/**
* Create the node given an id.
*
* @param id node id.
*/
public ASTEmptyFunction(int id) {
super(id);
}
/**
* Create a node with the given parser and id.
*
* @param p a parser.
* @param id node id.
*/
public ASTEmptyFunction(Parser p, int id) {
super(p, id);
}
/** {@inheritDoc} */
public Object jjtAccept(ParserVisitor visitor, Object data) {
return visitor.visit(this, data);
}
/** {@inheritDoc} */
public Object value(JexlContext jc) throws Exception {
SimpleNode sn = (SimpleNode) jjtGetChild(0);
/*
* I can't believe this
*/
Object o = sn.value(jc);
if (o == null) {
return Boolean.TRUE;
}
if (o instanceof String && "".equals(o)) {
return Boolean.TRUE;
}
if (o.getClass().isArray() && ((Object[]) o).length == 0) {
return Boolean.TRUE;
}
if (o instanceof Collection && ((Collection) o).isEmpty()) {
return Boolean.TRUE;
}
/*
* Map isn't a collection
*/
if (o instanceof Map && ((Map) o).isEmpty()) {
return Boolean.TRUE;
}
return Boolean.FALSE;
}
}