nomotion.yaml

name: nomotion
doc: |-
  Given an interval and a camera, this machine will emit a "no motion"
  message when the camera hasn't reported any motion for the given
  interval.  Once that report is emitted, no additional report will be
  emitted until new motion is detected.
paramspecs:
  camera:
    doc: The motion-detecting camera.
    primitiveType: string
  interval:
    doc: The interval during which no motion should be detected.
    primitiveType: string
patternsyntax: json
nodes:
  start:
    branching:
      branches:
      - target: listen
  listen:
    branching:
      type: message
      branches:
      - pattern: |
          {"event":{"instance":"?camera","mediaType":"event/cameraMotion","metaData":[{"name":"inMotion","value":"true"}]}}
        target: sawMotion
  sawMotion:
    action:
      doc: Cancel any pending timer, and make new timer.
      interpreter: ecmascript
      source: |-
        if (_.bindings.timerId) {
           _.out({"deleteTimer": _.bindings.timerId});
        }
        _.bindings.timerId = _.gensym();
        var message = {no:"motion", for: _.bindings.interval, from: _.bindings["?camera"]};
        _.out({"makeTimer": {id: _.bindings.timerId, in: _.bindings.interval, message: message}});
        return _.bindings;
    branching:
      branches:
      - target: listen