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.link;
016
017import org.apache.tapestry.IAction;
018import org.apache.tapestry.IActionListener;
019import org.apache.tapestry.IRequestCycle;
020import org.apache.tapestry.RenderRewoundException;
021import org.apache.tapestry.Tapestry;
022import org.apache.tapestry.engine.ActionServiceParameter;
023import org.apache.tapestry.engine.ILink;
024import org.apache.tapestry.listener.ListenerInvoker;
025
026/**
027 * A component for creating a link that is handled using the action service. [ <a
028 * href="../../../../../ComponentReference/ActionLink.html">Component Reference </a>]
029 * 
030 * @author Howard Lewis Ship
031 * @deprecated To be removed in 4.1
032 */
033
034public abstract class ActionLink extends AbstractLinkComponent implements IAction
035{
036    public abstract boolean isStateful();
037
038    /**
039     * Returns true if the stateful parameter is bound to a true value. If stateful is not bound,
040     * also returns the default, true.
041     * <p>
042     * Note that this method can be called when the component is not rendering, therefore it must
043     * directly access the {@link IBinding}for the stateful parameter.
044     */
045
046    public boolean getRequiresSession()
047    {
048        return isStateful();
049    }
050
051    public ILink getLink(IRequestCycle cycle)
052    {
053        String actionId = cycle.getNextActionId();
054
055        if (cycle.isRewound(this))
056        {
057            getListenerInvoker().invokeListener(getListener(), this, cycle);
058
059            throw new RenderRewoundException(this);
060        }
061
062        return getLink(cycle, Tapestry.ACTION_SERVICE, new ActionServiceParameter(this, actionId));
063    }
064
065    public abstract IActionListener getListener();
066
067    public abstract ListenerInvoker getListenerInvoker();
068}