/** | |
* All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); | |
* you may not use this file except in compliance with the License. | |
* You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, software | |
* distributed under the License is distributed on an "AS IS" BASIS, | |
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
* See the License for the specific language governing permissions and | |
* limitations under the License. | |
*/ | |
package org.jivesoftware.smack.provider; | |
import java.util.ArrayList; | |
import java.util.HashMap; | |
import java.util.List; | |
import java.util.Map; | |
import org.jivesoftware.smack.packet.PacketExtension; | |
import org.jivesoftware.smack.provider.PacketExtensionProvider; | |
import org.jivesoftware.smack.util.PacketParserUtils; | |
import org.jivesoftware.smackx.pubsub.provider.ItemProvider; | |
import org.jivesoftware.smackx.pubsub.provider.ItemsProvider; | |
import org.xmlpull.v1.XmlPullParser; | |
/** | |
* | |
* This class simplifies parsing of embedded elements by using the | |
* <a href="http://en.wikipedia.org/wiki/Template_method_pattern">Template Method Pattern</a>. | |
* After extracting the current element attributes and content of any child elements, the template method | |
* ({@link #createReturnExtension(String, String, Map, List)} is called. Subclasses | |
* then override this method to create the specific return type. | |
* | |
* <p>To use this class, you simply register your subclasses as extension providers in the | |
* <b>smack.properties</b> file. Then they will be automatically picked up and used to parse | |
* any child elements. | |
* | |
* <pre> | |
* For example, given the following message | |
* | |
* <message from='pubsub.shakespeare.lit' to='francisco@denmark.lit' id='foo> | |
* <event xmlns='http://jabber.org/protocol/pubsub#event> | |
* <items node='princely_musings'> | |
* <item id='asdjkwei3i34234n356'> | |
* <entry xmlns='http://www.w3.org/2005/Atom'> | |
* <title>Soliloquy</title> | |
* <link rel='alternative' type='text/html'/> | |
* <id>tag:denmark.lit,2003:entry-32397</id> | |
* </entry> | |
* </item> | |
* </items> | |
* </event> | |
* </message> | |
* | |
* I would have a classes | |
* {@link ItemsProvider} extends {@link EmbeddedExtensionProvider} | |
* {@link ItemProvider} extends {@link EmbeddedExtensionProvider} | |
* and | |
* AtomProvider extends {@link PacketExtensionProvider} | |
* | |
* These classes are then registered in the meta-inf/smack.providers file | |
* as follows. | |
* | |
* <extensionProvider> | |
* <elementName>items</elementName> | |
* <namespace>http://jabber.org/protocol/pubsub#event</namespace> | |
* <className>org.jivesoftware.smackx.provider.ItemsEventProvider</className> | |
* </extensionProvider> | |
* <extensionProvider> | |
* <elementName>item</elementName> | |
* <namespace>http://jabber.org/protocol/pubsub#event</namespace> | |
* <className>org.jivesoftware.smackx.provider.ItemProvider</className> | |
* </extensionProvider> | |
* | |
* </pre> | |
* | |
* @author Robin Collier | |
*/ | |
abstract public class EmbeddedExtensionProvider implements PacketExtensionProvider | |
{ | |
final public PacketExtension parseExtension(XmlPullParser parser) throws Exception | |
{ | |
String namespace = parser.getNamespace(); | |
String name = parser.getName(); | |
Map<String, String> attMap = new HashMap<String, String>(); | |
for(int i=0; i<parser.getAttributeCount(); i++) | |
{ | |
attMap.put(parser.getAttributeName(i), parser.getAttributeValue(i)); | |
} | |
List<PacketExtension> extensions = new ArrayList<PacketExtension>(); | |
do | |
{ | |
int tag = parser.next(); | |
if (tag == XmlPullParser.START_TAG) | |
extensions.add(PacketParserUtils.parsePacketExtension(parser.getName(), parser.getNamespace(), parser)); | |
} while (!name.equals(parser.getName())); | |
return createReturnExtension(name, namespace, attMap, extensions); | |
} | |
abstract protected PacketExtension createReturnExtension(String currentElement, String currentNamespace, Map<String, String> attributeMap, List<? extends PacketExtension> content); | |
} |