/*
* Copyright 2000-2016 Vaadin Ltd.
*
* 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 com.vaadin.data.provider;
import java.io.Serializable;
import elemental.json.JsonObject;
/**
* A data generator for {@link DataCommunicator}. Used to inject custom data to
* data items sent to the client for extension purposes.
*
* @author Vaadin Ltd.
*
* @param <T>
* the data type
*
* @since 8.0
*/
@FunctionalInterface
public interface DataGenerator<T> extends Serializable {
/**
* Adds custom data for the given item to its serialized {@code JsonObject}
* representation. This JSON object will be sent to client-side
* DataProvider.
*
* @param item
* the data item being serialized
* @param jsonObject
* the JSON object being sent to the client
*/
void generateData(T item, JsonObject jsonObject);
/**
* Informs the {@code DataGenerator} that the given data item has been
* dropped and is no longer needed. This method should clean up any unneeded
* information stored for this item.
*
* @param item
* the dropped data item
*/
public default void destroyData(T item) {
}
/**
* Informs the {@code DataGenerator} that all data has been dropped. This
* method should clean up any unneeded information stored for items.
*/
public default void destroyAllData() {
}
/**
* Informs the {@code DataGenerator} that a data object has been updated.
* This method should update any unneeded information stored for given item.
*
* @param item
* the updated item
*/
public default void refreshData(T item) {
}
}