// To add the AreaMeasurement2D widget to your map
var measurementWidget = new AreaMeasurement2D({
  view: view
});
view.ui.add(measurementWidget, "top-right");

Property Overview

Property Details

containerString|HTMLElement inherited

The ID or node representing the DOM element containing the widget. This property can only be set once.

declaredClassStringreadonly inherited

The name of the class. The declared class name is formatted as esri.folder.className.

destroyedBoolean inherited

When true, this property indicates whether the widget has been destroyed.

iconClassStringreadonly

The widget's default CSS icon class.

idString inherited

The unique ID assigned to the widget when the widget is created. If not set by the developer, it will default to the container ID, or if that is not present then it will be automatically generated.

labelStringreadonly

The widget's default label.

unitString

Unit system (imperial, metric) or specific unit used for displaying the area values.

Possible Values: metric | imperial | square-inches | square-feet | square-us-feet | square-yards | square-miles | square-meters | square-kilometers | acres | ares | hectares

Example:

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

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

unitOptionsString[]

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.

Example:

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

viewMapView

A reference to the MapView. Set this to link the widget to a specific view.

Example:

// Typical usage
var measurementWidget = new DistanceMeasurement2D({
  view: view
});
view.ui.add(measurementWidget, "top-right");

viewModelAreaMeasurement2DViewModelautocast

The view model for this widget. This is a class that contains all the logic (properties and methods) that controls this widget's behavior. See the AreaMeasurement2DViewModel class to access all properties and methods on the widget.

Example:

// Use the ViewModel to access and set advanced settings
var measurementWidget = new AreaMeasurement2D({
  viewModel: {
    view: view,
    mode: "planar",
    unit: "square-us-feet"
  }
});
view.ui.add(measurementWidget, "top-right");

Method Overview

Method Details

classes(classNames){String}inherited

A utility method used for building the value for a widget's class property. This aids in simplifying CSS class setup.

Prior to version 4.7, there were various approaches towards setting CSS classes. These were dependent upon variables, such as whether the classes were:

• a single static class,
• multiple static classes, or
• dynamic classes.

This helper method takes all of these approaches into account and simplifies it to use one single pattern to accommodate these multiple approaches.

Parameter:

classNames Array<(String|String[]|Object)> repeatable The class names.

Returns:

Type	Description
String	The computed class name.

See also:

• Guide - Widget development (rendering)

Example:

// .tsx syntax showing how to set CSS classes while rendering the widget
render() {
  const dynamicIconClasses = {
    [CSS.myIcon]: this.showIcon,
    [CSS.greyIcon]: !this.showIcon
  };

  return (
    <div class={classes(CSS.root, CSS.mixin, dynamicIconClasses)} />
  );
}

destroy()inherited

Destroys the widget instance.

emit(type, event)inherited

Emits an event on the instance. This method should only be used when creating subclasses of this class.

Parameters:

type String The name of the event.

event Object optional The event payload.

hasEventListener(type){Boolean}inherited

Indicates whether there is an event listener on the instance that matches the provided event name.

Parameter:

type String The name of the event.

Returns:

Type	Description
Boolean	Returns true if the class supports the input event.

on(type, listener){Object}inherited

Registers an event handler on the instance. Call this method to hook an event with a listener.

Parameters:

type String The name of event to listen for.

listener Function The function to call when the event is fired.

Returns:

Type	Description
Object	Returns an event handler with a remove() method that can be called to stop listening for the event. Property Type Description remove Function When called, removes the listener from the event.

See also:

• dojo/on

Example:

view.on("click", function(event){
  // event is the event handle returned after the event fires.
  console.log(event.mapPoint);
});

own(handles)inherited

Widget teardown helper. Any handles added to it will be automatically removed when the widget is destroyed.

Parameter:

handles WatchHandle|WatchHandle[] Handles marked for removal once the widget is destroyed.

postInitialize()inherited

This method is primarily used by developers when implementing custom widgets. Executes after widget is ready for rendering.

render(){Object}inherited

This method is primarily used by developers when implementing custom widgets. It must be implemented by subclasses for rendering.

Returns:

Type	Description
Object	The rendered virtual node.

renderNow()inherited

Renders widget to the DOM immediately.

scheduleRender()inherited

This method is primarily used by developers when implementing custom widgets. Schedules widget rendering. This method is useful for changes affecting the UI.