001/*
002 * (C) Copyright 2006-2007 Nuxeo SAS <http://nuxeo.com> and others
003 *
004 * All rights reserved. This program and the accompanying materials
005 * are made available under the terms of the Eclipse Public License v1.0
006 * which accompanies this distribution, and is available at
007 * http://www.eclipse.org/legal/epl-v10.html
008 *
009 * Contributors:
010 *     Jean-Marc Orliaguet, Chalmers
011 *
012 * $Id$
013 */
014
015package org.nuxeo.theme.jsf.negotiation.engine;
016
017import java.util.Map;
018
019import javax.faces.context.FacesContext;
020
021import org.nuxeo.theme.Manager;
022import org.nuxeo.theme.negotiation.Scheme;
023import org.nuxeo.theme.types.TypeFamily;
024
025public final class RequestParameter implements Scheme {
026
027    public String getOutcome(final Object context) {
028        final Map<String, String> parameters = ((FacesContext) context).getExternalContext().getRequestParameterMap();
029        final String engineName = parameters.get("engine");
030        if (Manager.getTypeRegistry().lookup(TypeFamily.ENGINE, engineName) != null) {
031            return engineName;
032        }
033        return null;
034    }
035
036}