Decorator is the base class for all decorator nodes. Thus, if you want to create new custom decorator nodes, you need to inherit from this class.

When creating decorator nodes, you will need to propagate the tick signal to the child node manually, just like the composite nodes. To do that, override the tick method and call the _execute method on the child node. For instance, take a look at how the Inverter node inherit this class and how it call its children:

// Inherit from Decorator, using the util function Class.
class Inverter extends b3.Decorator {

  constructor(){
    super({name: 'Invereter'});
  }

  tick: function(tick) {
    if (!this.child) {
      return b3.ERROR;
    }

    // Propagate the tick
    var status = this.child._execute(tick);

    if (status === b3.SUCCESS) {
      status = b3.FAILURE;
    } else if (status === b3.FAILURE) {
      status = b3.SUCCESS;
    }

    return status;
  }
});