/*
* $Id$
*
* 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.struts2.views.jasperreports;
import com.opensymphony.xwork2.util.ValueStack;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRField;
import net.sf.jasperreports.engine.JRRewindableDataSource;
import org.apache.struts2.util.MakeIterator;
import java.util.Iterator;
/**
* Ported to Struts.
*/
public class ValueStackDataSource implements JRRewindableDataSource {
/**
* Logger for this class
*/
private static Logger LOG = LoggerFactory.getLogger(ValueStackDataSource.class);
Iterator iterator;
ValueStack valueStack;
String dataSource;
boolean firstTimeThrough = true;
/**
* Create a value stack data source on the given iterable property
*
* @param valueStack The value stack to base the data source on
* @param dataSourceParam The property to iterate over for the report
*/
public ValueStackDataSource(ValueStack valueStack, String dataSourceParam) {
this.valueStack = valueStack;
dataSource = dataSourceParam;
Object dataSourceValue = valueStack.findValue(dataSource);
if (dataSourceValue != null) {
if (MakeIterator.isIterable(dataSourceValue)) {
iterator = MakeIterator.convert(dataSourceValue);
} else {
Object[] array = new Object[1];
array[0] = dataSourceValue;
iterator = MakeIterator.convert(array);
}
} else {
if (LOG.isWarnEnabled()) {
LOG.warn("Data source value for data source " + dataSource + " was null");
}
}
}
/**
* Get the value of a given field
*
* @param field The field to get the value for. The expression language to get the value
* of the field is either taken from the description property or from the name of the field
* if the description is <code>null</code>.
* @return an <code>Object</code> containing the field value or a new
* <code>ValueStackDataSource</code> object if the field value evaluates to
* an object that can be iterated over.
* @throws JRException if there is a problem obtaining the value
*/
public Object getFieldValue(JRField field) throws JRException {
//TODO: move the code to return a ValueStackDataSource to a seperate
// method when and if the JRDataSource interface is updated to support
// this.
String expression = field.getDescription();
if (expression == null) {
//Description is optional so use the field name as a default
expression = field.getName();
}
Object value = valueStack.findValue(expression);
if (LOG.isDebugEnabled()) {
LOG.debug("field: " + field.getName() + "/" + value);
}
if (MakeIterator.isIterable(value)) {
// return new ValueStackDataSource(this.valueStack, field.getName());
return new ValueStackDataSource(this.valueStack, expression);
} else {
return value;
}
}
/**
* Move to the first item.
*
* @throws JRException if there is a problem with moving to the first
* data element
*/
public void moveFirst() throws JRException {
Object dataSourceValue = valueStack.findValue(dataSource);
if (dataSourceValue != null) {
if (MakeIterator.isIterable(dataSourceValue)) {
iterator = MakeIterator.convert(dataSourceValue);
} else {
Object[] array = new Object[1];
array[0] = dataSourceValue;
iterator = MakeIterator.convert(array);
}
} else {
if (LOG.isWarnEnabled()) {
LOG.warn("Data source value for data source [" + dataSource + "] was null");
}
}
}
/**
* Is there any more data
*
* @return <code>true</code> if there are more elements to iterate over and
* <code>false</code> otherwise
* @throws JRException if there is a problem determining whether there
* is more data
*/
public boolean next() throws JRException {
if (firstTimeThrough) {
firstTimeThrough = false;
} else {
valueStack.pop();
}
if ((iterator != null) && (iterator.hasNext())) {
valueStack.push(iterator.next());
if (LOG.isDebugEnabled()) {
LOG.debug("Pushed next value: " + valueStack.findValue("."));
}
return true;
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("No more values");
}
return false;
}
}
}