content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you 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.causeway.applib.services.publishing.spi;
  
  import org.apache.causeway.applib.services.command.Command;
  import org.apache.causeway.commons.having.HasEnabling;
  
  /**
   * Part of the <i>Publishing SPI</i>. A component to receive {@link Command}s
   * (with publishing enabled) that just completed.
   *
   * @since 2.0 {@index}
   */
  public interface CommandSubscriber extends HasEnabling {
  
      /**
       * Notifies that the command will be published, and has transitioned to {@link org.apache.causeway.applib.services.command.Command.CommandPublishingPhase#READY}.
       *
       * <p>
       *     This is an opportunity for implementations to process the command,
       *     for example to persist an initial representation of it.
       * </p>
       */
      void onReady(Command command);
  
      /**
       * Notifies that the command has started to execute, and has transitioned to {@link org.apache.causeway.applib.services.command.Command.CommandPublishingPhase#STARTED}.
       *
       * <p>
       *     This is an opportunity for implementations to process the command,
       *     for example to update any persisted representation of it.
       * </p>
       */
      void onStarted(Command command);
  
      /**
       * Notifies that the command has completed and has transitioned to {@link org.apache.causeway.applib.services.command.Command.CommandPublishingPhase#COMPLETED}
       *
       * <p>
       *     This is an opportunity for implementations to process the command,
       *     for example to update any persisted representations of it.
       * </p>
       */
      void onCompleted(Command command);
  
  }
  