/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

interface rdfITripleVisitor;

/**
 * Interface used in RDF to describe data sources.
 *
 * @status PLASMA
 */

[scriptable, uuid(ebce86bd-1568-4a34-a808-9ccf9cde8087)]
interface rdfIDataSource : nsISupports
{
    /**
     * Visit all the subject resources in the datasource. The order is
     * intederminate and may change from one invocation to the next.
     * The subjects will be in the aSubject argument in calls into
     * aVisitor, aPredicate and aObject will be null.
     * @note Implementations may throw NS_ERROR_NOT_IMPLEMENTED for
     * this method, but in this case RDF serializations of this
     * datasource will not be possible.
     */
    void visitAllSubjects(in rdfITripleVisitor aVisitor);

    /**
     * Visit all the triples in the datasource. The order is
     * intederminate and may change from one invocation to the next.
     * @note Implementations may throw NS_ERROR_NOT_IMPLEMENTED for
     * this method, but in this case RDF serializations of this
     * datasource will not be possible.
     */
    void visitAllTriples(in rdfITripleVisitor aVisitor);
};