001// Copyright 2010 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.tapestry5; 016 017import java.io.IOException; 018 019import org.apache.tapestry5.annotations.Environmental; 020import org.apache.tapestry5.services.ComponentEventResultProcessor; 021import org.apache.tapestry5.services.Traditional; 022 023/** 024 * Extends {@link ComponentEventCallback} with a way to determine if the underlying event has been aborted 025 * due to a some event returning an acceptable, non-null value. The standard implementation of this 026 * is a wrapper around either the {@linkplain Traditional traditional} or 027 * {@linkplain org.apache.tapestry5.services.Ajax ajax} versions of the {@link ComponentEventResultProcessor} 028 * service, i.e., they allow for a navigational result. 029 * <p> 030 * Instances of this are made available via the {@link Environmental} annotation. 031 * 032 * @since 5.2.0 033 */ 034public interface TrackableComponentEventCallback<T> extends ComponentEventCallback<T> 035{ 036 /** 037 * Returns true if a return value from an event handler method was processed. 038 */ 039 boolean isAborted(); 040 041 /** 042 * If processing a return value threw an IOException, invoking this method will rethrow it. 043 */ 044 void rethrow() throws IOException; 045}