001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.gwt.client.rpc;
029
030import com.google.gwt.user.client.rpc.SerializationException;
031import com.google.gwt.user.client.rpc.SerializationStreamFactory;
032
033/**
034 * Utility class for deserializing prefetched RPC data.<p>
035 *
036 * @since 8.0
037 */
038public final class CmsRpcPrefetcher {
039
040    /**
041     * Hidden constructor.<p>
042     */
043    private CmsRpcPrefetcher() {
044
045        // empty
046    }
047
048    /**
049     * Deserializes the prefetched RPC data with the given dictionary name.<p>
050     *
051     * @param asyncService the RPC service instance
052     * @param dictionaryName the global variable name
053     *
054     * @return the prefetched RPC data
055     *
056     * @throws SerializationException if the deserialization fails
057     */
058    public static Object getSerializedObjectFromDictionary(Object asyncService, String dictionaryName)
059    throws SerializationException {
060
061        return getSerializedObjectFromString(asyncService, getString(dictionaryName));
062    }
063
064    /**
065     * Deserializes the prefetched RPC data.<p>
066     *
067     * @param asyncService the RPC service instance
068     * @param serializedData the serialized object data
069     *
070     * @return the prefetched RPC data
071     *
072     * @throws SerializationException if the deserialization fails
073     */
074    public static Object getSerializedObjectFromString(Object asyncService, String serializedData)
075    throws SerializationException {
076
077        SerializationStreamFactory ssf = (SerializationStreamFactory)asyncService;
078        return ssf.createStreamReader(serializedData).readObject();
079    }
080
081    /**
082     * Retrieves the given global variable as a string.<p>
083     *
084     * @param name the name of the variable to retrieve
085     *
086     * @return the variable's value
087     */
088    private static native String getString(String name) /*-{
089                                                        var metas = $wnd.document.getElementsByTagName('META');
090                                                        var i;
091                                                        for (i = 0; i < metas.length; i++) {
092                                                        if (metas[i].getAttribute('NAME') == name) {
093                                                        break;
094                                                        }
095                                                        }
096                                                        return metas[i].getAttribute("CONTENT");
097                                                        }-*/;
098}