var scaleBar = new ScaleBar({
  view: view
});
// Add widget to the bottom left corner of the view
view.ui.add(scaleBar, {
  position: "bottom-left"
});

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

Since: ArcGIS API for JavaScript 4.7

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.

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.

styleString

The style for the scale bar. When unit is set to dual, the style will always be line.

Possible Values: ruler | line

unitString

Units to use for the scale bar. When using dual, the scale bar displays both metric and non-metric units. Metric values show either kilometers or meters depending on the scale, and non-metric values show either miles or feet depending on the scale.

Possible Values: non-metric | metric | dual

Default Value:non-metric

viewMapView

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

viewModelScaleBarViewModelautocast

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 ScaleBarViewModel class to access all properties and methods on the widget.

Method Overview

Method Details

classes(classNames){String}inherited

Since: ArcGIS API for JavaScript 4.7

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

Since: ArcGIS API for JavaScript 4.5

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.