/*******************************************************************************
 * Copyright (c) 2004, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - Initial API and implementation
 *     Jens Lukowski/Innoopract - initial renaming/restructuring
 *******************************************************************************/
package org.eclipse.wst.common.uriresolver.internal.provisional;

import org.eclipse.core.resources.IFile;

/**
 * An extension to augment the behaviour of a URIResolver.  Extensions are project aware
 * so that they can apply specialized project specific resolving rules. 
 */
public interface URIResolverExtension {
	/**
	 * @param file the in-workspace base resource, if one exists
	 * @param baseLocation - the location of the resource that contains the uri
	 * @param publicId - an optional public identifier (i.e. namespace name), or null if none
	 * @param systemId - an absolute or relative URI, or null if none 
	 * 
	 * @return an absolute URI or null if this extension can not resolve this reference
	 */
	public String resolve(IFile file, String baseLocation, String publicId, String systemId);
}