1. @override
dynamic onInvoke(Map<String, dynamic> params)

This is called when this node is invoked. You can return the following types from this method:

  • Iterable
  • Map
  • Table
  • Stream
  • SimpleTableResult
  • AsyncTableResult

You can also return a future that resolves to one (like if the method is async) of the following types:

  • Stream
  • Iterable
  • Map
  • Table

Source 

@override
onInvoke(Map<String, dynamic> params) {
  var inputPath = params["Path"];
  dynamic val = params["Value"];
  String ts = params["Timestamp"];

  if (ts == null) {
    ts = ValueUpdate.getTs();
  }

  if (inputPath is! String) {
    throw "Path not provided.";
  }

  Path p = new Path(path);
  String tp = p
    .parent
    .child(NodeNamer.createName(inputPath))
    .path;
  SimpleNode node = _link[tp];

  WatchPathNode pn;
  if (node is! WatchPathNode) {
    pn = _link.addNode(tp, {
      r"$name": inputPath,
      r"$is": "watchPath",
      r"$publish": true,
      r"$type": "dynamic",
      r"$path": inputPath
    });
    _link.save();
  } else {
    pn = node;
  }

  pn.doUpdate(new ValueUpdate(val, ts: ts));
}