    001    // Copyright 2006 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
    015    package org.apache.tapestry5.services;
    016
    017    /**
    018     * Represents a previously stored change to a persistent field, within the context of a particular page of the
    019     * application.
    020     */
    021    public interface PersistentFieldChange
    022    {
    023        /**
    024         * Returns the nested id of the component, or the empty string for the page's root component.
    025         */
    026        String getComponentId();
    027
    028        /**
    029         * Returns the name of the field for which a change was recorded.
    030         */
    031        String getFieldName();
    032
    033        /**
    034         * Returns the new value for the field (which may be null).
    035         */
    036        Object getValue();
    037    }