AreaMeasurement2DViewModel | API Reference | ArcGIS Maps SDK for JavaScript 4.30

Provides the logic for the AreaMeasurement2D widget.

See also

Constructors

AreaMeasurement2DViewModel Constructor new AreaMeasurement2DViewModel(properties)

Parameter

properties Object

optional

See the properties for a list of all the properties that may be passed into the constructor.

Property Overview

Type	Summary	Class
Number	Threshold (in meters) which determines the method for computing and displaying areas and perimeters in non-Web Mercator projected coordinate systems (PCS).	AreaMeasurement2DViewModel
Object	The area and perimeter of the measurement polygon in square meters and meters respectively.	AreaMeasurement2DViewModel
Object	This property returns the locale specific representation of the area and perimeter.	AreaMeasurement2DViewModel
String	The ViewModel's state.	AreaMeasurement2DViewModel
SystemOrAreaUnit	Unit system (imperial, metric) or specific unit used for displaying the area values.	AreaMeasurement2DViewModel
SystemOrAreaUnit []	List of available units and unit systems (imperial, metric) for displaying the area values.	AreaMeasurement2DViewModel
MapView	The view from which the widget will operate.	AreaMeasurement2DViewModel

Property Details

geodesicDistanceThreshold Property geodesicDistanceThreshold Number Deprecated since version 4.29.

Threshold (in meters) which determines the method for computing and displaying areas and perimeters in non-Web Mercator projected coordinate systems (PCS).

Below this threshold, they are computed in a Euclidean manner (in their respective PCS).
Above this threshold, they are computed geodetically.

If the threshold is omitted (default), areas and perimeters are always computed in a Euclidean manner.

This property is ignored if the map’s spatial reference is a geographic coordinate system (GCS) or Web Mercator. Meaning that areas and perimeters are always computed geodetically.

Default Value:null

Example

// To set the threshold at 10 km
let measurementWidget = new AreaMeasurement2D({
  viewModel: {
    view: view,
    geodesicDistanceThreshold: 10000
  }
});

measurement Property measurement Objectreadonly

The area and perimeter of the measurement polygon in square meters and meters respectively.

Properties: area Number

The area (m²).

perimeter Number

The perimeter (m).

geometry Polygon

Measurement area.

Example

// 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
    );
  }
);

measurementLabel Property measurementLabel Objectreadonly

This property returns the locale specific representation of the area and perimeter. Areas and perimeters are rounded to two decimal places. Areas are sourced from the measurement property (in square meters) and converted to the user defined units/system.

Properties: area Number

The area (m²).

perimeter Number

The perimeter (m).

Example

// 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
    );
  }
);

state Property state Stringreadonly

The ViewModel's state.

Value	Description
disabled	not ready yet
ready	ready for measuring
measuring	measuring has started
measured	measuring has finished

Possible Values:"disabled" |"ready" |"measuring" |"measured"

Default Value:disabled

Example

// 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)
);

unit Property unit SystemOrAreaUnit

Unit system (imperial, metric) or specific unit used for displaying the area values. Possible values are listed in unitOptions.

Example

// 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);

unitOptions Property unitOptions SystemOrAreaUnit[]

List of available units and unit systems (imperial, metric) for displaying the area values. By default, the following units are included: metric, imperial, square-inches, square-feet, square-us-feet, square-yards, square-miles, square-meters, square-kilometers, acres, ares, hectares. Possible unit values can only be a subset of this list.

Example

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

view Property view MapView

The view from which the widget will operate.

Example

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

Method Overview

Name	Return Type	Summary	Class
		Clears the current measurement.	AreaMeasurement2DViewModel
		Starts a new measurement.	AreaMeasurement2DViewModel

Method Details

clear Method clear() Since: ArcGIS Maps SDK for JavaScript 4.16 AreaMeasurement2DViewModel since 4.10, clear added at 4.16.

Clears the current measurement.

start Method start() Since: ArcGIS Maps SDK for JavaScript 4.16 AreaMeasurement2DViewModel since 4.10, start added at 4.16.

Starts a new measurement.

Example

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

await areaMeasurement2DViewModel.start();