org.apache.commons.jexl.parser.ASTForeachStatement 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 java.util.Iterator;
import org.apache.commons.jexl.JexlContext;
import org.apache.commons.jexl.util.introspection.Info;
/**
* ForEach statement. Syntax: foreach (var in iterable) Statement()
*
* @author Dion Gillard
* @since 1.1
*/
public class ASTForeachStatement extends SimpleNode {
/** dummy velocity info. */
private static final Info DUMMY = new Info("", 1, 1);
/** index of the loop variable. */
private static final int VAR_INDEX = 0;
/** index of the items. */
private static final int ITEMS_INDEX = 1;
/** index of the code to execute. */
private static final int STATEMENT_INDEX = 2;
/**
* Create the node given an id.
*
* @param id node id.
*/
public ASTForeachStatement(int id) {
super(id);
}
/**
* Create a node with the given parser and id.
*
* @param p a parser.
* @param id node id.
*/
public ASTForeachStatement(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 {
Object result = null;
/* first child is the loop variable */
ASTReference loopVariable = (ASTReference) jjtGetChild(VAR_INDEX);
/* second child is the variable to iterate */
SimpleNode iterable = (SimpleNode) jjtGetChild(ITEMS_INDEX);
Object iterableValue = iterable.value(jc);
// make sure there is a value to iterate on and a statement to execute
if (iterableValue != null && jjtGetNumChildren() >= (STATEMENT_INDEX + 1)) {
/* third child is the statement to execute */
SimpleNode statement = (SimpleNode) jjtGetChild(2);
// get an iterator for the collection/array etc via the
// introspector.
Iterator itemsIterator = getUberspect().getIterator(
iterableValue, DUMMY);
while (itemsIterator.hasNext()) {
// set loopVariable to value of iterator
Object value = itemsIterator.next();
jc.getVars().put(loopVariable.getRootString(), value);
// execute statement
result = statement.value(jc);
}
}
return result;
}
}