Regexp.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.functions;

import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

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

/**
 * Performs regexp matching.
 *
 * @author Markus Michael Geipel
 */
public final class Regexp extends AbstractFunction {

	private Matcher matcher;
	private String format;
	private final Map<String, String> tempVars = new HashMap<String, String>();

	@Override
	public void receive(final String name, final String value,
			final NamedValueSource source, final int recordCount,
			final int entityCount) {
		matcher.reset(value);
		if (null == format) {
			while (matcher.find()) {
				final String group = matcher.group();
				if (!group.isEmpty()) {
					getNamedValueReceiver().receive(name, group, this,
							recordCount, entityCount);
				}
			}
		} else {
			while (matcher.find()) {
				populateVars();
				if (!tempVars.isEmpty()) {
					getNamedValueReceiver().receive(name,
							StringUtil.format(format, tempVars), this,
							recordCount, entityCount);
				}
			}
		}
	}

	private void populateVars() {
		tempVars.clear();
		for (int i = 0; i <= matcher.groupCount(); ++i) {
			final String group = matcher.group(i);
			if (group != null && !group.isEmpty()) {
				tempVars.put(String.valueOf(i), group);
			}
		}
	}

	public void setMatch(final String match) {
		this.matcher = Pattern.compile(match).matcher("");
	}

	public void setFormat(final String format) {
		this.format = format;
	}

}