// Copyright 2006, 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.tapestry.services; | |
import java.util.Collection; | |
/** | |
* Defines how changes to fields (within components, within pages) may have their values persisted between requests. | |
* Different implementations store the field values {@linkplain org.apache.tapestry.internal.services.SessionPersistentFieldStrategy | |
* in the session}, {@linkplain org.apache.tapestry.internal.services.ClientPersistentFieldStrategy on the client}, or | |
* elsewhere. | |
*/ | |
public interface PersistentFieldStrategy | |
{ | |
/** | |
* Posts a change of a persistent property. | |
* | |
* @param pageName the name of the page containing the component | |
* @param componentId the nested id path of the component (or null for the page's root component) | |
* @param fieldName the name of the field whose persistent value has changed | |
* @param newValue the new value for the field, possibly null | |
*/ | |
void postChange(String pageName, String componentId, String fieldName, Object newValue); | |
/** | |
* Finds all persistent changes previously stored for the named page (for the current active session or client). | |
*/ | |
Collection<PersistentFieldChange> gatherFieldChanges(String pageName); | |
/** | |
* Discards any saved changes for the name page. There is no expectation that data already gathered from the | |
* strategy and persumably dumped into component instance fields will be affected, but future field access (within | |
* this request or a later one) will show no data for the indicated page. | |
* | |
* @param pageName logical name of page whose field persistent data should be discarded | |
*/ | |
void discardChanges(String pageName); | |
} |