/*

 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.xml.bind;

/**

 * A basic event handler interface for validation errors.

 *

 * <p>

 * If an application needs to implement customized event handling, it must

 * implement this interface and then register it with either the

 * {@link Unmarshaller#setEventHandler(ValidationEventHandler) Unmarshaller},

 * the {@link Validator#setEventHandler(ValidationEventHandler) Validator}, or

 * the {@link Marshaller#setEventHandler(ValidationEventHandler) Marshaller}.

 * The JAXB Provider will then report validation errors and warnings encountered

 * during the unmarshal, marshal, and validate operations to these event

 * handlers.

 *

 * <p>

 * the JAXB Provider must treat that as if the method returned false, effectively

 * terminating whatever operation was in progress at the time (unmarshal,

 * validate, or marshal).

 *

 * <p>

 * Modifying the Java content tree within your event handler is undefined

 * by the specification and may result in unexpected behaviour.

 *

 * <p>

 * encountering a fatal error is undefined by the specification and may result

 * in unexpected behavior.

 *

 * <p>

 * <b>Default Event Handler</b>

 * <blockquote>

 *    See: <a href="Validator.html#defaulthandler">Validator javadocs</a>

 * </blockquote>

 *

 * @see Unmarshaller

 * @see Validator

 * @see Marshaller

 * @see ValidationEvent

 * @see javax.xml.bind.util.ValidationEventCollector

 * @since 1.6, JAXB 1.0

 */

public interface ValidationEventHandler {

    /**

     * Receive notification of a validation warning or error.

     *

     * The ValidationEvent will have a

     * {@link ValidationEventLocator ValidationEventLocator} embedded in it that

     * indicates where the error or warning occurred.

     *

     * <p>

     * If an unchecked runtime exception is thrown from this method, the JAXB

     * provider will treat it as if the method returned false and interrupt

     * the current unmarshal, validate, or marshal operation.

     *

     * @param event the encapsulated validation event information.  It is a

     * provider error if this parameter is null.

     * @return true if the JAXB Provider should attempt to continue the current

     *         unmarshal, validate, or marshal operation after handling this

     *         warning/error, false if the provider should terminate the current

     * @throws IllegalArgumentException if the event object is null.

     */

    public boolean handleEvent( ValidationEvent event );

}