/*
* 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.cocoon.forms.expression;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Collection;
import java.util.Iterator;
import org.outerj.expression.AbstractExpression;
import org.outerj.expression.Expression;
import org.outerj.expression.ExpressionContext;
import org.outerj.expression.ExpressionException;
/**
* Sum function. This function returns the sum of all of its argument, but
* it accepts Collections or Iterators as arguments. When it finds such an
* argument it iterates on all it's values, and try to sum them as well. It
* accepts String and any instance of Number.
*/
public class SumFunction extends AbstractExpression {
public Object evaluate(ExpressionContext context) throws ExpressionException {
BigDecimal result = new BigDecimal("0");
for(int i = 0; i < arguments.size(); i++) {
Expression function = (Expression)arguments.get(i);
Object ret = function.evaluate(context);
if (ret instanceof Collection) {
ret = ((Collection)ret).iterator();
}
if (ret instanceof Iterator) {
Iterator iter = (Iterator)ret;
while (iter.hasNext()) {
Object p = iter.next();
BigDecimal db = null;
if (p instanceof BigDecimal) {
db =(BigDecimal)p;
} else if (p instanceof Long) {
db = new BigDecimal(((Long)p).longValue());
} else if (p instanceof Integer) {
db = new BigDecimal(((Integer)p).intValue());
} else if (p instanceof Double) {
db = new BigDecimal(((Double)p).doubleValue());
} else if (p instanceof Float) {
db = new BigDecimal(((Float)p).floatValue());
} else if (p instanceof BigInteger) {
db = new BigDecimal((BigInteger)p);
} else if (p instanceof Number) {
db = new BigDecimal(((Number)p).doubleValue());
} else if (p instanceof String) {
db = new BigDecimal((String)p);
} else {
throw new IllegalArgumentException("Cannot sum an argument of type " + p.getClass().getName());
}
result = result.add(db);
}
} else {
result = result.add((BigDecimal)function.evaluate(context));
}
}
return result;
}
public Class getResultType() {
return BigDecimal.class;
}
public String getDescription() {
return "Summatory";
}
}