| // Copyright 2006, 2008, 2010 The Apache Software Foundation |
| // |
| // Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package org.apache.tapestry5; |
| |
| /** |
| * Callback interface for a {@linkplain org.apache.tapestry5.runtime.Event render phase event) or |
| * |
| * @link org.apache.tapestry5.runtime.ComponentEvent}, notified when a non-null value is returned from some event |
| * handler method. |
| */ |
| public interface ComponentEventCallback<T> |
| { |
| /** |
| * Invoked to handle a non-null event handler method result. The handler should determine whether the value is |
| * acceptable, and throw an exception if not. Any thrown exception will be wrapped to identify the component and |
| * method from which the value was returned. |
| * <p/> |
| * Boolean values are <em>not</em> passed to the callback. Booleans are used to indicate that the event has been |
| * handled (true, meaning the event is handled and aborted) or that a further search for handlers should continue |
| * (false, meaning the event was not handled, is not aborted, and the search up the component hierarchy for event |
| * handler methods should continue). If a component event method returns true, then |
| * {@link org.apache.tapestry5.runtime.Event#isAborted()} will return true. |
| * |
| * @param result |
| * the result value returned from the event handler method |
| * @return true if the event is aborted, false if the event may continue |
| */ |
| boolean handleResult(T result); |
| } |
