maint-5-2/tapestry-core/src/main/java/org/apache/tapestry5/services/ComponentEventRequestHandler.java

// Copyright 2006, 2007, 2008 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.services;

import org.apache.tapestry5.ioc.annotations.UsesOrderedConfiguration;

import java.io.IOException;

/**
 * Handler interface for component event requests. Component event requests <em>do things</em> such as process a form
 * submission or otherwise change state. In the majority of cases, after the component event, a redirect response is
 * sent to the client which, in turn, causes a page render.
 * <p/>
 * The ComponentEventRequestHandler service is a pipeline, allowing extensibility via contributed {@linkplain
 * org.apache.tapestry5.services.ComponentEventRequestFilter filters}.    It may be distinguished by the @{@link
 * org.apache.tapestry5.services.Traditional} marker annotation.
 * <p/>
 * A second service, AjaxComponentEventRequestHandler is also a pipeline and may be distinguished by the @{@link
 * org.apache.tapestry5.services.Ajax} marker annotation.
 *
 * @see org.apache.tapestry5.corelib.components.ActionLink
 * @see org.apache.tapestry5.corelib.components.Form
 */
@UsesOrderedConfiguration(ComponentEventRequestFilter.class)
public interface ComponentEventRequestHandler
{
    /**
     * Handler for a component action request which will trigger an event on a component and use the return value to
     * send a response to the client (typically, a redirect to a page render URL).
     *
     * @param parameters defining the requst
     */
    void handle(ComponentEventRequestParameters parameters) throws IOException;
}