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.
   */
  
  /**
   * The {@link org.apache.causeway.applib.services.publishing.spi.EntityPropertyChangeSubscriber} 
   * service provides a simple mechanism to capture changes to data. 
   * It is called for each property that has changed on any entity object 
   * (when enabled for publishing), as a set of pre- and post-values.
   * 
   * The {@link org.apache.causeway.applib.services.publishing.spi.ExecutionSubscriber} API is intended 
   * for coarse-grained publish/subscribe for system-to-system interactions, from Apache Causeway 
   * to some other system. Events that can be published are action invocations/property edits, 
   * and changed objects. A typical use case is to publish onto a pub/sub bus such as 
   * ActiveMQ with Camel to keep other systems up to date.
   * 
   * TODO v2 publishing/subscribing now has even more participants
   */
  package org.apache.causeway.applib.services.publishing;
  