Coverage Report - org.apache.commons.scxml.invoke.Invoker

Classes in this File Line Coverage Branch Coverage Complexity
Invoker
N/A 
N/A 
1

 1  
 /*
 2  
  * Licensed to the Apache Software Foundation (ASF) under one or more
 3  
  * contributor license agreements.  See the NOTICE file distributed with
 4  
  * this work for additional information regarding copyright ownership.
 5  
  * The ASF licenses this file to You under the Apache License, Version 2.0
 6  
  * (the "License"); you may not use this file except in compliance with
 7  
  * the License.  You may obtain a copy of the License at
 8  
  *
 9  
  *     http://www.apache.org/licenses/LICENSE-2.0
 10  
  *
 11  
  * Unless required by applicable law or agreed to in writing, software
 12  
  * distributed under the License is distributed on an "AS IS" BASIS,
 13  
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 14  
  * See the License for the specific language governing permissions and
 15  
  * limitations under the License.
 16  
  */
 17  
 package org.apache.commons.scxml.invoke;
 18  
 
 19  
 import java.util.Map;
 20  
 
 21  
 import org.apache.commons.scxml.SCInstance;
 22  
 import org.apache.commons.scxml.TriggerEvent;
 23  
 
 24  
 /**
 25  
  * <p>The Invoker interface is used to define the possible interactions
 26  
  * between the parent state machine (executor) and the types of invocable
 27  
  * activities.</p>
 28  
  *
 29  
  * <p>Invocable activities must first register an Invoker implementation class
 30  
  * for the appropriate "targettype" (attribute of &lt;invoke&gt;) with the
 31  
  * parent <code>SCXMLExecutor</code>.</p>
 32  
  *
 33  
  * <p>The communication link between the parent state machine executor and
 34  
  * the invoked activity is a bi-directional events pipe.</p>
 35  
  *
 36  
  * <p>All events triggered on the parent state machine get forwarded to the
 37  
  * invoked activity. The processing semantics for these events depend
 38  
  * upon the "targettype", and thereby vary per concrete implementation of
 39  
  * this interface.</p>
 40  
  *
 41  
  * <p>The invoked activity in turn must fire a special "done" event
 42  
  * when it concludes. It may fire additional events before the "done"
 43  
  * event. The semantics of any additional events depend upon the
 44  
  * "targettype". The invoked activity must not fire any events after the
 45  
  * "done" event. The name of the special "done" event must be
 46  
  * the ID of the parent state wherein the corresponding &lt;invoke&gt;
 47  
  * resides, with the String ".invoke.done" appended.</p>
 48  
  *
 49  
  * <p>The Invoker "lifecycle" is outlined below:
 50  
  *  <ol>
 51  
  *   <li>Instantiation via {@link Class#newInstance()}
 52  
  *       (Invoker implementation requires accessible constructor).</li>
 53  
  *   <li>Configuration (setters for parent state ID and
 54  
  *       {@link SCInstance}).</li>
 55  
  *   <li>Initiation of invoked activity via invoke() method, passing
 56  
  *       the source URI and the map of params.</li>
 57  
  *   <li>Zero or more bi-directional event triggering.</li>
 58  
  *   <li>Either completion or cancellation.</li>
 59  
  *  </ol>
 60  
  * </p>
 61  
  */
 62  
 public interface Invoker {
 63  
 
 64  
     /**
 65  
      * Set the state ID of the owning state for the &lt;invoke&gt;.
 66  
      * Implementations must use this ID for constructing the event name for
 67  
      * the special "done" event (and optionally, for other event names
 68  
      * as well).
 69  
      *
 70  
      * @param parentStateId The ID of the parent state.
 71  
      */
 72  
     void setParentStateId(String parentStateId);
 73  
 
 74  
     /**
 75  
      * Set the "context" of the parent state machine, which provides the
 76  
      * channel.
 77  
      *
 78  
      * @param scInstance The "context" of the parent state machine.
 79  
      */
 80  
     void setSCInstance(SCInstance scInstance);
 81  
 
 82  
     /**
 83  
      * Begin this invocation.
 84  
      *
 85  
      * @param source The source URI of the activity being invoked.
 86  
      * @param params The &lt;param&gt; values
 87  
      * @throws InvokerException In case there is a fatal problem with
 88  
      *                          invoking the source.
 89  
      */
 90  
     void invoke(String source, Map params)
 91  
     throws InvokerException;
 92  
 
 93  
     /**
 94  
      * Forwards the events triggered on the parent state machine
 95  
      * on to the invoked activity.
 96  
      *
 97  
      * @param evts
 98  
      *            an array of external events which triggered during the last
 99  
      *            time quantum
 100  
      *
 101  
      * @throws InvokerException In case there is a fatal problem with
 102  
      *                          processing the events forwarded by the
 103  
      *                          parent state machine.
 104  
      */
 105  
     void parentEvents(TriggerEvent[] evts)
 106  
     throws InvokerException;
 107  
 
 108  
     /**
 109  
      * Cancel this invocation.
 110  
      *
 111  
      * @throws InvokerException In case there is a fatal problem with
 112  
      *                          canceling this invoke.
 113  
      */
 114  
     void cancel()
 115  
     throws InvokerException;
 116  
 
 117  
 }
 118