/**
* Copyright (C) 2001-2017 by RapidMiner and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapidminer.com
*
* This program is free software: you can redistribute it and/or modify it under the terms of the
* GNU Affero General Public License as published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License along with this program.
* If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.operator.collections;
import com.rapidminer.operator.IOObject;
import com.rapidminer.operator.IOObjectCollection;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.operator.ports.OutputPort;
import com.rapidminer.operator.ports.metadata.CollectionMetaData;
import com.rapidminer.operator.ports.metadata.MDTransformationRule;
import com.rapidminer.operator.ports.metadata.MetaData;
/**
* Turns a collection of collections into a flat collection.
*
* @author Simon Fischer
*
*/
public class UnfoldOperator extends Operator {
private final InputPort collectionInput = getInputPorts().createPort("collection", new CollectionMetaData());
private final OutputPort flatOutput = getOutputPorts().createPort("flat");
public UnfoldOperator(OperatorDescription description) {
super(description);
getTransformer().addRule(new MDTransformationRule() {
@Override
public void transformMD() {
MetaData md = collectionInput.getMetaData();
if ((md != null) && (md instanceof CollectionMetaData)) {
flatOutput.deliverMD(new CollectionMetaData(((CollectionMetaData) md).getElementMetaDataRecursive()));
} else {
flatOutput.deliverMD(null);
}
}
});
}
@Override
public void doWork() throws OperatorException {
IOObjectCollection<?> collection = collectionInput.getData(IOObjectCollection.class);
flatOutput.deliver(new IOObjectCollection<IOObject>(collection.getObjectsRecursive()));
}
}