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    
015    package org.apache.tapestry;
016    
017    /**
018     *  A particular type of component usuable with the
019     *  action service.
020     *
021     *  @author Howard Lewis Ship
022     *  @since 1.0.1
023     */
024    
025    public interface IAction extends IComponent
026    {
027        /**
028         *  Returns true if the component requires 
029         *  an existing, not new, {@link javax.servlet.http.HttpSession}
030         *  to operate.  Components who are not dependant on page state
031         *  (or the visit object) are non-stateful and can return false.
032         *
033         **/
034    
035        public boolean getRequiresSession();
036    }