001// Copyright 2004, 2005 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry.engine;
016
017import java.util.Collection;
018import java.util.Collections;
019
020/**
021 * Concrete implementation of {@link org.apache.tapestry.IEngine} used for ordinary applications.
022 * All page state information is maintained in the {@link javax.servlet.http.HttpSession} using
023 * instances of {@link org.apache.tapestry.record.SessionPageRecorder}.
024 * 
025 * @author Howard Lewis Ship
026 */
027
028public class BaseEngine extends AbstractEngine
029{
030    /**
031     * Returns an unmodifiable {@link Collection} of the page names for which {@link IPageRecorder}
032     * instances exist. Note: Starting in 4.0, this method is deprecated and returns an empty list.
033     * 
034     * @deprecated
035     */
036
037    public Collection getActivePageNames()
038    {
039        return Collections.EMPTY_LIST;
040
041    }
042}