AreaMeasurement2DViewModel

// After creating and adding the AreaMeasurement2D widget
let measurementWidget = new AreaMeasurement2D({
  view: view
});
view.ui.add(measurementWidget, "top-right");

// Raw measurements (in meters) can be accessed from this property
reactiveUtils.watch(
() => measurementWidget.viewModel.measurement,
  (measurement) => {
    console.log(
       "Area: ", measurement.area,
       "Perimeter: ", measurement.perimeter
    );
  }
);

// After creating and adding the AreaMeasurement2D widget
let measurementWidget = new AreaMeasurement2D({
  view: view
});
view.ui.add(measurementWidget, "top-right");

// Measurement labels can be accessed from this property
reactiveUtils.watch(
() => measurementWidget.viewModel.measurementLabel,
  (label) => {
    console.log(
       "Area: ", label.area,
       "Perimeter: ", label.perimeter
    );
  }
);

// To display the state of the AreaMeasurement2D widget
let measurementWidget = new AreaMeasurement2D({
  view: view
});
reactiveUtils.watch(
  () => measurementWidget.viewModel.state,
  (state) => console.log("Current state: ", state)
);

// To create the AreaMeasurement2D widget that displays area in square US feet
let measurementWidget = new AreaMeasurement2D({
  viewModel: {
    view: view,
    unit: "square-us-feet"
  }
});

// To display the current measurement unit
console.log('Current unit: ', measurementWidget.viewModel.unit);

// To display the available units to the console
let measurementWidget = new AreaMeasurement2D({
  view: view
});
console.log('All units: ', measurementWidget.viewModel.unitOptions.join(", "));

// To create the AreaMeasurement2D widget with the view property
let measurementWidget = new AreaMeasurement2D({
  viewModel: {
    view: view
  }
});

const areaMeasurement2DViewModel = new AreaMeasurement2DViewModel({
  view: view,
  unit: "square-yards"
});

await areaMeasurement2DViewModel.start();