    001// Copyright 2006, 2007, 2008 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
    015package org.apache.tapestry5.internal.services;
    016
    017import org.apache.tapestry5.ComponentResources;
    018import org.apache.tapestry5.ioc.annotations.UsesMappedConfiguration;
    019import org.apache.tapestry5.services.PersistentFieldBundle;
    020import org.apache.tapestry5.services.PersistentFieldStrategy;
    021
    022/**
    023 * Handle persistent property changes. Primarily, delegates to a number of {@link org.apache.tapestry5.services.PersistentFieldStrategy}
    024 * instances.
    025 */
    026@UsesMappedConfiguration(PersistentFieldStrategy.class)
    027public interface PersistentFieldManager
    028{
    029    /**
    030     * Posts a change of a persistent property.
    031     *
    032     * @param pageName  the logical name of the page containing the component
    033     * @param resources the resources for the component or mixin (used to determine the persistence strategy)
    034     * @param fieldName the name of the field whose persistent value has changed
    035     * @param newValue  the new value for the field, possibly null
    036     */
    037    void postChange(String pageName, ComponentResources resources, String fieldName, Object newValue);
    038
    039    /**
    040     * Locates all persistently stored changes to all properties within the page (for the current session and request)
    041     * and gathers them together into a bundle.
    042     *
    043     * @param pageName the logical name of the page to gather changes for
    044     * @return a bundle identifying all such changes
    045     */
    046    PersistentFieldBundle gatherChanges(String pageName);
    047
    048    /**
    049     * Discards all changes for the indicated page. This will not affect pages that have already been attached to this
    050     * request, but will affect subsequent page attachments in this and later requests.
    051     *
    052     * @param pageName logical name of page whose persistent field data is to be discarded
    053     */
    054    void discardChanges(String pageName);
    055
    056    /**
    057     * Discards changes on the indicated page for a specific strategy only. This will not affect pages that have already
    058     * been attached to this request, but will affect subsequent page attachments in this and later requests.
    059     *
    060     * @param pageName logical name of page whose persistent field data is to be discarded
    061     *
    062     * @param strategyName name of the strategy of which field data is to be discarded
    063     */
    064    void discardChanges(String pageName, String strategyName);
    065
    066}