/**
* 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.UserError;
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;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeBoolean;
import com.rapidminer.parameter.ParameterTypeInt;
import java.util.List;
/**
* Selects a single object from an {@link IOObjectCollection}.
*
* @author Simon Fischer
*
*/
public class SelectionOperator extends Operator {
public static final String PARAMETER_INDEX = "index";
public static final String PARAMETER_UNFOLD = "unfold";
private final InputPort collectionInput = getInputPorts().createPort("collection",
new CollectionMetaData(new MetaData()));
private final OutputPort selectedOutput = getOutputPorts().createPort("selected");
public SelectionOperator(OperatorDescription description) {
super(description);
getTransformer().addRule(new MDTransformationRule() {
@Override
public void transformMD() {
MetaData md = collectionInput.getMetaData();
if (md instanceof CollectionMetaData) {
if (getParameterAsBoolean(PARAMETER_UNFOLD)) {
selectedOutput.deliverMD(((CollectionMetaData) md).getElementMetaDataRecursive());
} else {
selectedOutput.deliverMD(((CollectionMetaData) md).getElementMetaData());
}
} else {
selectedOutput.deliverMD(null);
}
}
});
}
@Override
public void doWork() throws OperatorException {
@SuppressWarnings("unchecked")
IOObjectCollection<IOObject> collection = collectionInput.getData(IOObjectCollection.class);
List<IOObject> elements;
if (getParameterAsBoolean(PARAMETER_UNFOLD)) {
elements = collection.getObjectsRecursive();
} else {
elements = collection.getObjects();
}
int index = getParameterAsInt(PARAMETER_INDEX);
if ((index < 1) || (index > elements.size())) {
throw new UserError(this, 159, index, elements.size());
}
selectedOutput.deliver(elements.get(index - 1));
}
@Override
public List<ParameterType> getParameterTypes() {
List<ParameterType> types = super.getParameterTypes();
types.add(new ParameterTypeInt(PARAMETER_INDEX, "Index within the collection of the object to return", 1,
Integer.MAX_VALUE, 1, false));
types.add(new ParameterTypeBoolean(
PARAMETER_UNFOLD,
"If checked, collections are unfolded, i.e., if the collection contains other collections, the children will be concatenated and then the element at the given index will be looked up.",
false));
return types;
}
}