Added UserItemsProvider for use with contact service discovery additions in r8779.

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/branches@8780 b35dd754-fafc-0310-a699-88a17e54d16e

pep/src/java/org/jivesoftware/openfire/disco/UserItemsProvider.java

+/**
+ * $RCSfile: $
+ * $Revision: $
+ * $Date: $
+ *
+ * Copyright (C) 2007 Jive Software. All rights reserved.
+ *
+ * This software is published under the terms of the GNU Public License (GPL),
+ * a copy of which is included in this distribution.
+ */
+
+package org.jivesoftware.openfire.disco;
+
+import java.util.Iterator;
+
+import org.dom4j.Element;
+import org.xmpp.packet.JID;
+
+/**
+ * <p>
+ * A <code>UserItemsProvider</code> is responsible for providing the items associated with a user
+ * that are to be discovered during a disco#items query sent to the user.
+ * </p>
+ * 
+ * <p>
+ * Examples of when a <code>UserItemsProvider</code> is used include:
+ * </p>
+ * <ul>
+ * <li>For discovering PEP items of a user.</li>
+ * <li>For discovering available resources of a user.</li>
+ * </ul>
+ * </p>
+ *
+ * @author Armando Jagucki
+ */
+public interface UserItemsProvider {
+
+    /**
+     * Returns an Iterator (of Element) with the target entity's items or null if none. Each Element
+     * must include a JID attribute and may include the name and node attributes of the entity. In
+     * case that the sender of the disco request is not authorized to discover items an
+     * UnauthorizedException will be thrown.
+     *
+     * @param name the recipient JID's name.
+     * @param senderJID the XMPPAddress of user that sent the disco items request.
+     * @return an Iterator (of Element) with the target entity's items or null if none.
+     */
+    public abstract Iterator<Element> getUserItems(String name, JID senderJID);
+}