Combine.java

/*
 * Copyright 2013, 2014 Deutsche Nationalbibliothek
 *
 * Licensed 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.culturegraph.mf.metamorph.collectors;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.culturegraph.mf.commons.StringUtil;
import org.culturegraph.mf.metamorph.api.NamedValueSource;
import org.culturegraph.mf.metamorph.api.helpers.AbstractFlushingCollect;

/**
 * Corresponds to the <code><collect></code> tag.
 *
 * @author Markus Michael Geipel
 */
public final class Combine extends AbstractFlushingCollect {

	private final Map<String, String> variables = new HashMap<String, String>();
	private final Set<NamedValueSource> sources = new HashSet<NamedValueSource>();
	private final Set<NamedValueSource> sourcesLeft = new HashSet<NamedValueSource>();

	@Override
	protected void emit() {
		final String name = StringUtil.format(getName(), variables);
		final String value = StringUtil.format(getValue(), variables);
		getNamedValueReceiver().receive(name, value, this, getRecordCount(),
				getEntityCount());
	}

	@Override
	protected boolean isComplete() {
		return sourcesLeft.isEmpty();
	}

	@Override
	protected void receive(final String name, final String value,
			final NamedValueSource source) {
		variables.put(name, value);
		sourcesLeft.remove(source);
	}

	@Override
	public void onNamedValueSourceAdded(final NamedValueSource namedValueSource) {
		sources.add(namedValueSource);
		sourcesLeft.add(namedValueSource);
	}

	@Override
	protected void clear() {
		sourcesLeft.addAll(sources);
		variables.clear();
	}

}