Measurement | References | ArcGIS Maps SDK for JavaScript

import Measurement from "@arcgis/core/widgets/Measurement.js";

Inheritance:: Measurement→Widget→Accessor

Since: ArcGIS Maps SDK for JavaScript 4.13

The Measurement widget groups and manages multiple measurement tools and allows you to easily switch between them using the activeTool property. The tools correspond to the measurement widgets for area and distance in 2D (AreaMeasurement2D, DistanceMeasurement2D) and in 3D (AreaMeasurement3D, DirectLineMeasurement3D).

This widget follows a composite pattern that allows developers to configure the UI to best match their specific requirements. The measurement tools, placements, and icons can all be configured, which offers great flexibility to use with tabbed interfaces or other customized UI. See the Measurement widget sample for an example of this flexibility.

How distances, areas, and perimeters are computed depends on the view type and its spatial reference.

In 2D MapViews:

In geographic coordinate systems (GCS) and in Web Mercator, they are computed geodetically.
In projected coordinate systems (PCS), apart from Web Mercator, they are computed in a Euclidean manner (in their respective PCS).

In 3D SceneViews:

In geographic coordinate systems (GCS) and in Web Mercator:
- horizontal distance is computed geodetically;
- vertical distance is computed as a difference in z-values;
- direct distance is computed in a Euclidean manner;
- area and perimeter are computed:
  - in a Euclidean manner if the perimeter is below 100km;
  - geodetically if the perimeter is above 100km.
In projected coordinate systems (PCS), apart from Web Mercator:
- all three distances (direct, horizontal, and vertical), areas, and perimeters are computed in a Euclidean manner (in their respective PCS).

See also

Example

// Add the measurement widget to the upper right hand corner
// with the distance tool active
const map = new Map({
  basemap: "hybrid"
});

const view = new MapView({
  container: "viewDiv",
  map: map,
  center: [-71.69, 43.76],
  zoom: 15
});

const measurement = new Measurement({
  view: view,
  activeTool: "distance"
});
view.ui.add(measurement, "top-right");

// Switch between area and distance measurement
function switchTool() {
 const tool = measurement.activeTool === "distance" ? "area" : "distance";
 measurement.activeTool = tool;
}

Constructors

Constructor

Parameters

Parameter	Type	Description	Required
properties	`MeasurementProperties`

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

Properties

Any properties can be set, retrieved or listened to. See the Watch for changes topic.

Property	Type	Class
`activeTool`	`MeasurementComponentType \| null \| undefined`
`activeWidget` readonly	`MeasurementWidget \| null \| undefined`
`areaUnit`	`SystemOrAreaUnit`
`container` inherited	`HTMLElement \| null \| undefined`	Widget
`declaredClass` readonly inherited	`string`	Accessor
`destroyed` readonly inherited	`boolean`	Widget
`icon`	`Icon["icon"]`
`id` inherited	`string`	Widget
`label`	`string`
`linearUnit`	`SystemOrLengthUnit`
`view`	`MapViewOrSceneView \| null \| undefined`
`viewModel`	`MeasurementViewModel`
`visible` inherited	`boolean`	Widget

activeTool

Property

Type: MeasurementComponentType | null | undefined

Specifies the current measurement tool to display. Setting its value to area activates the area measurement tool and it works for both MapView and SceneView. To measure distance in a MapView set the property to distance and in a SceneView set it to direct-line. If this property is not set, the widget will not be displayed.

Example

// To create the Measurement widget with SceneView's direct-line tool active.
const measurement = new Measurement({
  view: view,
  activeTool: "direct-line"
});

// To switch between direct line and area measurement tools
function switchTool() {
 const tool = measurement.activeTool === "direct-line" ? "area" : "direct-line";
 measurement.activeTool = tool;
}

activeWidget

readonly Property

Type: MeasurementWidget | null | undefined

The measurement widget that is currently being used. Use this property to get access to the active widget.

Example

// Print the active widget to the console.
const measurement = new Measurement({
  view: view,
  activeTool: "distance"
});
view.ui.add(measurement, "top-right");
console.log("Active Widget: ", measurement.activeWidget);

areaUnit

Property

Type: SystemOrAreaUnit

Unit system (imperial, metric) or specific unit used for displaying the area values. Possible values are: metric, imperial, square-inches, square-feet, square-us-feet, square-yards, square-miles, square-nautical-miles, square-meters, square-kilometers, acres, ares, hectares.

Example

// To create the Measurement widget that displays area in square US feet
const measurement = new Measurement({
  view: view,
  activeTool: "area",
  areaUnit: "square-us-feet"
});

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

container

autocast inherited Property

Type: HTMLElement | null | undefined

Inherited from: Widget

The ID or node representing the DOM element containing the widget. This property can only be set once. The following examples are all valid use case when working with widgets.

Examples

// Create the HTML div element programmatically at runtime and set to the widget's container
const basemapGallery = new BasemapGallery({
  view: view,
  container: document.createElement("div")
});

// Add the widget to the top-right corner of the view
view.ui.add(basemapGallery, {
  position: "top-right"
});

// Specify an already-defined HTML div element in the widget's container

const basemapGallery = new BasemapGallery({
  view: view,
  container: basemapGalleryDiv
});

// Add the widget to the top-right corner of the view
view.ui.add(basemapGallery, {
  position: "top-right"
});

// HTML markup
<body>
  <div id="viewDiv"></div>
  <div id="basemapGalleryDiv"></div>
</body>

// Specify the widget while adding to the view's UI
const basemapGallery = new BasemapGallery({
  view: view
});

// Add the widget to the top-right corner of the view
view.ui.add(basemapGallery, {
  position: "top-right"
});

declaredClass

readonlyinherited Property

Type: string

Inherited from: Accessor

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

destroyed

readonlyinherited Property

Type: boolean

Inherited from: Widget

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

icon

autocast Property

Type: Icon["icon"]

Since: ArcGIS Maps SDK for JavaScript 4.27

Icon which represents the widget. It is typically used when the widget is controlled by another one (e.g. in the Expand widget).

See also

Default value: "measure"

id

inherited Property

Type: string

Inherited from: Widget

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.

label

autocast Property

Type: string

The widget's default label. This property is useful whenever the widget is controlled by another one (e.g. Expand).

linearUnit

Property

Type: SystemOrLengthUnit

Unit system (imperial, metric) or specific unit used for displaying the distance values. Possible values are: metric, imperial, inches, feet, us-feet, yards, miles, nautical-miles, meters, kilometers.

Example

// To create the Measurement widget that displays distance in yards
const measurement = new Measurement({
  view: view,
  activeTool: "distance",
  linearUnit: "yards"
});

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

view

Property

Type: MapViewOrSceneView | null | undefined

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

Example

// To create the Measurement widget for SceneView with the direct-line tool active.
const measurement = new Measurement({
  view: sceneView,
  activeTool: "direct-line"
});

viewModel

autocast Property

Type: MeasurementViewModel

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

Example

// Initialize a measurement widget using the view model.
const measurement = new Measurement({
  viewModel: {
    view: view,
    activeTool: "distance",
    unit: "yards"
  }
});

visible

inherited Property

Type: boolean

Inherited from: Widget

Indicates whether the widget is visible.

If false, the widget will no longer be rendered in the web document. This may affect the layout of other elements or widgets in the document. For example, if this widget is the first of three widgets associated to the upper right hand corner of the DefaultUI, then the other widgets will reposition when this widget is made invisible. For more information, refer to the css display value of "none".

Default value: true

Example

// Hides the widget in the view
widget.visible = false;

Methods

Method	Signature	Class
`classes` inherited	`classes(...classNames: ((string \| null \| undefined) \| ((string[] \| Record<string, boolean>) \| null \| undefined) \| false \| null \| undefined)[]): string`	Widget
`clear`	`clear(): void`
`destroy` inherited	`destroy(): void`	Widget
`emit` inherited	`emit<Type extends EventNames<this>>(type: Type, event?: this["@eventTypes"][Type]): boolean`	EventedMixin
`hasEventListener` inherited	`hasEventListener<Type extends EventNames<this>>(type: Type): boolean`	EventedMixin
`isFulfilled` inherited	`isFulfilled(): boolean`	EsriPromiseMixin
`isRejected` inherited	`isRejected(): boolean`	EsriPromiseMixin
`isResolved` inherited	`isResolved(): boolean`	EsriPromiseMixin
`on` inherited	`on<Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle`	EventedMixin
`postInitialize` inherited	`postInitialize(): void`	Widget
`render` inherited	`render(): any \| null`	Widget
`renderNow` inherited	`renderNow(): void`	Widget
`scheduleRender` inherited	`scheduleRender(): void`	Widget
`startMeasurement`	`startMeasurement(): void`
`when` inherited	`when<TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> \| null \| undefined, onRejected?: OnRejectedCallback<TResult2> \| null \| undefined): Promise<TResult1 \| TResult2>`	EsriPromiseMixin

classes

inherited Method

Signature: classes (...classNames: ((string | null | undefined) | ((string[] | Record<string, boolean>) | null | undefined) | false | null | undefined)[]): string

Inherited from: Widget

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

Parameters

Parameter	Type	Description	Required
classNames	`((string \| null \| undefined) \| ((string[] \| Record<string, boolean>) \| null \| undefined) \| false \| null \| undefined)[]`	The class names.

Returns: string
The computed class name.

Example

// .tsx syntax showing how to set css classes while rendering the widget

render() {
  const dynamicClasses = {
    [css.flip]: this.flip,
    [css.primary]: this.primary
  };

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

clear

Method

Signature: clear (): void

Removes all measurement widgets and associated graphics.

Returns: void

destroy

inherited Method

Signature: destroy (): void

Inherited from: Widget

Destroys the widget instance.

Returns: void

emit

inherited Method

Signature: emit <Type extends EventNames<this>>(type: Type, event?: this["@eventTypes"][Type]): boolean

Type parameters: <Type extends EventNames<this>>

Inherited from: EventedMixin

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

Parameters

Parameter	Type	Description	Required
type	`Type`	The name of the event.
event	`this["@eventTypes"][Type]`	The event payload.

Returns: boolean
true if a listener was notified

hasEventListener

inherited Method

Signature: hasEventListener <Type extends EventNames<this>>(type: Type): boolean

Type parameters: <Type extends EventNames<this>>

Inherited from: EventedMixin

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

Parameters

Parameter	Type	Description	Required
type	`Type`	The name of the event.

Returns: boolean
Returns true if the class supports the input event.

isFulfilled

inherited Method

Signature: isFulfilled (): boolean

Inherited from: EsriPromiseMixin

isFulfilled() may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected). If it is fulfilled, true will be returned.

Returns: boolean
Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected).

isRejected

inherited Method

Signature: isRejected (): boolean

Inherited from: EsriPromiseMixin

isRejected() may be used to verify if creating an instance of the class is rejected. If it is rejected, true will be returned.

Returns: boolean
Indicates whether creating an instance of the class has been rejected.

isResolved

inherited Method

Signature: isResolved (): boolean

Inherited from: EsriPromiseMixin

isResolved() may be used to verify if creating an instance of the class is resolved. If it is resolved, true will be returned.

Returns: boolean
Indicates whether creating an instance of the class has been resolved.

on

inherited Method

Signature: on <Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle

Type parameters: <Type extends EventNames<this>>

Inherited from: EventedMixin

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

Parameters

Parameter	Type	Description	Required
type	`Type`	An event or an array of events to listen for.
listener	`EventedCallback<this["@eventTypes"][Type]>`	The function to call when the event fires.

Returns

ResourceHandle

Returns an event handler with a remove() method that should be called to stop listening for the event(s).

Property	Type	Description
remove	Function	When called, removes the listener from the event.

Example

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

postInitialize

inherited Method

Signature: postInitialize (): void

Inherited from: Widget

Executes after widget is ready for rendering.

Returns: void

render

inherited Method

Signature: render (): any | null

Inherited from: Widget

This method is implemented by subclasses for rendering.

Returns: any | null
The rendered virtual node.

renderNow

inherited Method

Signature: renderNow (): void

Inherited from: Widget

Renders widget to the DOM immediately.

Returns: void

scheduleRender

inherited Method

Signature: scheduleRender (): void

Inherited from: Widget

Schedules widget rendering. This method is useful for changes affecting the UI.

Returns: void

startMeasurement

Method

Signature: startMeasurement (): void

Starts a new measurement for the active measurement widget.

Returns: void

Example

const measurement = new Measurement({
  view: view,
  activeTool: "distance"
});

function measure () {
  measurement.startMeasurement();
}

measure();

when

inherited Method

Signature: when <TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> | null | undefined, onRejected?: OnRejectedCallback<TResult2> | null | undefined): Promise<TResult1 | TResult2>

Type parameters: <TResult1 = this, TResult2 = never>

Inherited from: EsriPromiseMixin

when() may be leveraged once an instance of the class is created. This method takes two input parameters: an onFulfilled function and an onRejected function. The onFulfilled executes when the instance of the class loads. The onRejected executes if the instance of the class fails to load.

Parameters

Parameter	Type	Description	Required
onFulfilled	`OnFulfilledCallback<this, TResult1> \| null \| undefined`	The function to call when the promise resolves.
onRejected	`OnRejectedCallback \| null \| undefined`	The function to execute when the promise fails.

Returns: Promise<TResult1 | TResult2>
Returns a new promise for the result of onFulfilled that may be used to chain additional functions.

Example

// Although this example uses MapView, any class instance that is a promise may use when() in the same way
let view = new MapView();
view.when(function(){
  // This function will execute once the promise is resolved
}, function(error){
  // This function will execute if the promise is rejected due to an error
});

Type definitions

AreaMeasurement

Type definition

Type: AreaMeasurement2D | AreaMeasurement3D

DistanceMeasurement

Type definition

Type: DistanceMeasurement2D | DirectLineMeasurement3D

MeasurementWidget

Type definition

Type: AreaMeasurement | DistanceMeasurement