/*
 * 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.shared.annotations;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Target;

import com.vaadin.shared.communication.ServerRpc;

/**
 * Invoking a method in a {@link ServerRpc} interface marked with this
 * annotation will only add the invocation to a queue of outgoing RPC
 * invocations, but it will not cause the queue to be purged and sent to the
 * server. The queue will instead be sent when any RPC method not marked
 * as @Delayed has been invoked.
 *
 * @author Vaadin Ltd
 * @version @VERSION@
 * @since 7.0.0
 */
@Target(ElementType.METHOD)
@Documented
public @interface Delayed {
    /**
     * By setting lastOnly to <code>true</code>, any previous invocations of the
     * same method will be removed from the queue when a new invocation is
     * added. This can be used in cases where only the last value is of
     * interest.
     * <p>
     * The default value is <code>false</code> which means that invoking the
     * method multiple times will cause multiple invocations to be enqueued and
     * eventually sent to the server.
     *
     * @return <code>true</code> if only the last invocation of the annotated
     *         method should be sent to the server, <code>false</code> if all
     *         enqueued invocations should be sent.
     */
    public boolean lastOnly() default false;
}