/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla.
 *
 * The Initial Developer of the Original Code is
 * Benjamin Smedberg <bsmedberg@covad.net>.
 * Portions created by the Initial Developer are Copyright (C) 2004
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Axel Hecht <axel@pike.org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsISupports.idl"

interface nsIRDFResource;
interface nsIRDFNode;

/**
 * Interface used in RDF to enumerate triples.
 * Also used by rdfIDataSource::getAllSubjects, then aPredicate,
 * aObject and aTruthValue are ignored.
 *
 * @status PLASMA
 */

[scriptable, function, uuid(aafea151-c271-4505-9978-a100d292800c)]
interface rdfITripleVisitor : nsISupports
{
    /**
     * Callback function for returning query results.
     *
     * @param aSubject, aPredicate, aObject describe the (sub-)arc
     * @returnCode NS_RDF_STOP_VISIT to stop iterating over the query result.
     *             Any error code will stop the iteration as well.
     */
    void visit(in nsIRDFNode aSubject, in nsIRDFResource aPredicate,
               in nsIRDFNode aObject, in boolean aTruthValue);
};