ObjectTemplate.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.formatting;

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.framework.FluxCommand;
import org.culturegraph.mf.framework.ObjectReceiver;
import org.culturegraph.mf.framework.annotations.Description;
import org.culturegraph.mf.framework.annotations.In;
import org.culturegraph.mf.framework.annotations.Out;
import org.culturegraph.mf.framework.helpers.DefaultObjectPipe;
import org.culturegraph.mf.framework.objects.Triple;


/**
 * Builds a {@link String} from a template and an {@link Object}. ${o} marks
 * the place where the object is to be inserted. If the received object in an
 * instance of Triple ${s}, ${p} and ${o} are used instead.
 *
 * @param <T>
 *            object type
 *
 * @author Markus Geipel
 *
 */
@Description("Builds a String from a template and an Object. Provide template in brackets. ${o} marks the place where the object is to be inserted. " +
		"If the object in an instance of Triple ${s}, ${p} and ${o} are used instead")
@In(Object.class)
@Out(String.class)
@FluxCommand("template")
public final class ObjectTemplate<T> extends DefaultObjectPipe<T, ObjectReceiver<String>> {

	//TODO: make replace more efficient
	private static final Pattern OBJ_PATTERN = Pattern.compile("${o}", Pattern.LITERAL);
	private final Map<String, String> vars = new HashMap<String, String>();
	private final String template;

	public ObjectTemplate(final String template) {
		super();
		this.template = template;
	}

	@Override
	public void process(final T obj) {
		if(obj instanceof Triple){
			final Triple triple = (Triple)obj;
			vars.put("s", triple.getSubject());
			vars.put("p", triple.getPredicate());
			vars.put("o", triple.getObject());
			getReceiver().process(StringUtil.format(template, vars));
		}else{
			final Matcher matcher = OBJ_PATTERN.matcher(template);
			getReceiver().process(matcher.replaceAll(obj.toString()));
		}
	}
}