/*******************************************************************************
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.ofbiz.webapp.event;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.ofbiz.webapp.control.ConfigXMLReader.Event;
import org.apache.ofbiz.webapp.control.ConfigXMLReader.RequestMap;

/**
 * EventHandler - Event Handler Interface
 */

public interface EventHandler {

    /**
     * Initializes the handler. Since handlers use the singleton pattern this method should only be called
     * the first time the handler is used.
     * @param context ServletContext This may be needed by the handler in order to lookup properties or XML
     * definition files for rendering pages or handler options.
     * @throws EventHandlerException
     */
    void init(ServletContext context) throws EventHandlerException;

    /**
     * Invoke the web event
     * @param event Contains information about what to execute
     * @param requestMap Contains information about the request-map the event was called from
     * @param request The servlet request object
     * @param response The servlet response object
     *@return String Result code
     *@throws EventHandlerException
     */
    String invoke(Event event, RequestMap requestMap, HttpServletRequest request, HttpServletResponse response) throws EventHandlerException;
}
