001/**
002 *
003 * Copyright 2003-2007 Jive Software.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.jivesoftware.smack.packet;
019
020/**
021 * Interface to represent packet extensions. A packet extension is an XML subdocument
022 * with a root element name and namespace. Packet extensions are used to provide
023 * extended functionality beyond what is in the base XMPP specification. Examples of
024 * packet extensions include message events, message properties, and extra presence data.
025 * IQ packets cannot contain packet extensions.
026 *
027 * @see DefaultPacketExtension
028 * @see org.jivesoftware.smack.provider.PacketExtensionProvider
029 * @author Matt Tucker
030 */
031public interface PacketExtension {
032
033    /**
034     * Returns the root element name.
035     *
036     * @return the element name.
037     */
038    public String getElementName();
039
040    /**
041     * Returns the root element XML namespace.
042     *
043     * @return the namespace.
044     */
045    public String getNamespace();
046
047    /**
048     * Returns the XML representation of the PacketExtension.
049     *
050     * @return the packet extension as XML.
051     */
052    public CharSequence toXML();
053}