/*
 * Copyright 2014-15 (C) Tom Parker <thpr@users.sourceforge.net>
 * 
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 * 
 * This library 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 Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package pcgen.output.actor;

import pcgen.cdom.base.CDOMObject;
import pcgen.cdom.base.Constants;
import pcgen.cdom.enumeration.CharID;
import pcgen.cdom.enumeration.ObjectKey;
import pcgen.cdom.facet.FacetLibrary;
import pcgen.cdom.facet.ObjectWrapperFacet;
import pcgen.output.base.OutputActor;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;

/**
 * A ObjectKeyActor is designed to process an interpolation and convert that
 * into a TemplateModel representing the contents of the specific Integer being
 * requested by its ObjectKey
 * 
 * Note that the actual name of the interpolation is stored externally to this
 * Actor (in CDOMObjectWrapperInfo to be precise)
 * 
 * @param <T>
 *            The Type of object contained by the ObjectKey underlying this
 *            ObjectKeyActor
 */
public class ObjectKeyActor<T> implements OutputActor<CDOMObject>
{
	private static final ObjectWrapperFacet WRAPPER_FACET = FacetLibrary
		.getFacet(ObjectWrapperFacet.class);

	/**
	 * The ObjectKey underlying this ObjectKeyActor (for which the contents will
	 * be returned)
	 */
	private final ObjectKey<T> ok;

	/**
	 * Constructs a new ObjectKeyActor with the given ObjectKey
	 * 
	 * @param ok
	 *            The ObjectKey underlying this ObjectKeyActor
	 */
	public ObjectKeyActor(ObjectKey<T> ok)
	{
		this.ok = ok;
	}

	/**
	 * @see pcgen.output.base.OutputActor#process(pcgen.cdom.enumeration.CharID,
	 *      java.lang.Object)
	 */
	@Override
	public TemplateModel process(CharID id, CDOMObject d)
		throws TemplateModelException
	{
		Object object = d.get(ok);
		if (object == null)
		{
			object = Constants.EMPTY_STRING;
		}
		return WRAPPER_FACET.wrap(id, object);
	}
}