    001// Licensed under the Apache License, Version 2.0 (the "License");
    002// you may not use this file except in compliance with the License.
    003// You may obtain a copy of the License at
    004//
    005// http://www.apache.org/licenses/LICENSE-2.0
    006//
    007// Unless required by applicable law or agreed to in writing, software
    008// distributed under the License is distributed on an "AS IS" BASIS,
    009// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    010// See the License for the specific language governing permissions and
    011// limitations under the License.
    012
    013package org.apache.tapestry5;
    014
    015import org.apache.tapestry5.annotations.Environmental;
    016import org.apache.tapestry5.services.ComponentEventResultProcessor;
    017import org.apache.tapestry5.services.Traditional;
    018
    019import java.io.IOException;
    020
    021/**
    022 * Extends {@link ComponentEventCallback} with a way to determine if the underlying event has been aborted
    023 * due to a some event returning an acceptable, non-null value. The standard implementation of this
    024 * is a wrapper around either the {@linkplain Traditional traditional} or
    025 * {@linkplain org.apache.tapestry5.services.Ajax ajax} versions of the {@link ComponentEventResultProcessor}
    026 * service, i.e., they allow for a navigational result.
    027 *
    028 * Instances of this are made available via the {@link Environmental} annotation.
    029 *
    030 * @since 5.2.0
    031 */
    032public interface TrackableComponentEventCallback<T> extends ComponentEventCallback<T>
    033{
    034    /**
    035     * Returns true if a return value from an event handler method was processed.
    036     */
    037    boolean isAborted();
    038
    039    /**
    040     * If processing a return value threw an IOException, invoking this method will rethrow it.
    041     */
    042    void rethrow() throws IOException;
    043}