Measurement

AMD: require(["esri/widgets/Measurement"], (Measurement) => { /* code goes here */ });
ESM: import Measurement from "@arcgis/core/widgets/Measurement.js";
Class: esri/widgets/Measurement
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.

measurement-widget

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).
For information about gaining full control of widget styles, see the Styling topic.
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

Measurement

Constructor
new Measurement(properties)
Parameter
properties Object
optional

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

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.
Show inherited properties Hide inherited properties
Name Type Summary Class
String

Specifies the current measurement tool to display.

Measurement
AreaMeasurement2D|AreaMeasurement3D|DirectLineMeasurement3D|DistanceMeasurement2D

The measurement widget that is currently being used.

Measurement
SystemOrAreaUnit

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

Measurement
String|HTMLElement

The ID or node representing the DOM element containing the widget.

Widget
String

The name of the class.

Accessor
String

Icon which represents the widget.

Measurement
String

The widget's default CSS icon class.

Measurement
String

The unique ID assigned to the widget when the widget is created.

Widget
String

The widget's default label.

Measurement
SystemOrLengthUnit

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

Measurement
MapView|SceneView

A reference to the MapView or SceneView.

Measurement
MeasurementViewModel

The view model for this widget.

Measurement
Boolean

Indicates whether the widget is visible.

Widget

Property Details

activeTool

Property
activeTool String

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.

Possible Values:"area"|"distance"|"direct-line"

Default Value:null
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;
}

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

Default Value:null
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
areaUnit 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-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

Inherited
Property
container String|HTMLElement
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

Inherited
Property
declaredClass Stringreadonly
Inherited from Accessor

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

icon

Property
icon String
Since: ArcGIS Maps SDK for JavaScript 4.27 Measurement since 4.13, icon added at 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).

Default Value:null
See also

iconClass

Property
iconClass String
Deprecated since 4.27. Use icon instead.

The widget's default CSS icon class.

id

Inherited
Property
id 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

Property
label String

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

linearUnit

Property
linearUnit 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
view MapView|SceneView

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

Property
viewModel MeasurementViewModelautocast

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
visible 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 view UI, 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;

Method Overview

Show inherited methods Hide inherited methods
Name Return Type Summary Class

Adds one or more handles which are to be tied to the lifecycle of the object.

Accessor
String

A utility method used for building the value for a widget's class property.

Widget

Removes all measurement widgets and associated graphics.

Measurement

Destroys the widget instance.

Widget
Boolean

Emits an event on the instance.

Widget
Boolean

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

Widget
Boolean

Returns true if a named group of handles exist.

Accessor
Boolean

isFulfilled() may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected).

Widget
Boolean

isRejected() may be used to verify if creating an instance of the class is rejected.

Widget
Boolean

isResolved() may be used to verify if creating an instance of the class is resolved.

Widget
Object

Registers an event handler on the instance.

Widget

Adds one or more handles which are to be tied to the lifecycle of the widget.

Widget

This method is primarily used by developers when implementing custom widgets.

Widget

Removes a group of handles owned by the object.

Accessor
Object

This method is primarily used by developers when implementing custom widgets.

Widget

Renders widget to the DOM immediately.

Widget

This method is primarily used by developers when implementing custom widgets.

Widget

Starts a new measurement for the active measurement widget.

Measurement
Promise

when() may be leveraged once an instance of the class is created.

Widget

Method Details

addHandles

Inherited
Method
addHandles(handleOrHandles, groupKey)
Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, addHandles added at 4.25.

Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.

// Manually manage handles
const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true }
);

this.addHandles(handle);

// Destroy the object
this.destroy();
Parameters
handleOrHandles WatchHandle|WatchHandle[]

Handles marked for removal once the object is destroyed.

groupKey *
optional

Key identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.

classes

Inherited
Method
classes(classNames){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.

Parameter
classNames String|String[]|Object
repeatable

The class names.

Returns
Type Description
String The computed class name.
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)} />
  );
}

clear

Method
clear()

Removes all measurement widgets and associated graphics.

destroy

Inherited
Method
destroy()
Inherited from Widget

Destroys the widget instance.

emit

Inherited
Method
emit(type, event){Boolean}
Inherited from Widget

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.

Returns
Type Description
Boolean true if a listener was notified

hasEventListener

Inherited
Method
hasEventListener(type){Boolean}
Inherited from Widget

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.

hasHandles

Inherited
Method
hasHandles(groupKey){Boolean}
Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, hasHandles added at 4.25.

Returns true if a named group of handles exist.

Parameter
groupKey *
optional

A group key.

Returns
Type Description
Boolean Returns true if a named group of handles exist.
Example
// Remove a named group of handles if they exist.
if (obj.hasHandles("watch-view-updates")) {
  obj.removeHandles("watch-view-updates");
}

isFulfilled

Inherited
Method
isFulfilled(){Boolean}
Inherited from Widget
Since: ArcGIS Maps SDK for JavaScript 4.19 Widget since 4.2, isFulfilled added at 4.19.

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
Type Description
Boolean Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected).

isRejected

Inherited
Method
isRejected(){Boolean}
Inherited from Widget
Since: ArcGIS Maps SDK for JavaScript 4.19 Widget since 4.2, isRejected added at 4.19.

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

Returns
Type Description
Boolean Indicates whether creating an instance of the class has been rejected.

isResolved

Inherited
Method
isResolved(){Boolean}
Inherited from Widget
Since: ArcGIS Maps SDK for JavaScript 4.19 Widget since 4.2, isResolved added at 4.19.

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

Returns
Type Description
Boolean Indicates whether creating an instance of the class has been resolved.

on

Inherited
Method
on(type, listener){Object}
Inherited from Widget

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

Parameters

An event or an array of events to listen for.

listener Function

The function to call when the event fires.

Returns
Type Description
Object 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);
});

own

Inherited
Method
own(handleOrHandles)
Inherited from Widget
Since: ArcGIS Maps SDK for JavaScript 4.24 Widget since 4.2, own added at 4.24.
Deprecated since 4.28 Use addHandles() instead.

Adds one or more handles which are to be tied to the lifecycle of the widget. The handles will be removed when the widget is destroyed.

const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true}
);

this.own(handle); // Handle gets removed when the widget is destroyed.
Parameter
handleOrHandles WatchHandle|WatchHandle[]

Handles marked for removal once the widget is destroyed.

postInitialize

Inherited
Method
postInitialize()
Inherited from Widget

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

removeHandles

Inherited
Method
removeHandles(groupKey)
Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, removeHandles added at 4.25.

Removes a group of handles owned by the object.

Parameter
groupKey *
optional

A group key or an array or collection of group keys to remove.

Example
obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");

render

Inherited
Method
render(){Object}
Inherited from Widget

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
Method
renderNow()
Inherited from Widget

Renders widget to the DOM immediately.

scheduleRender

Inherited
Method
scheduleRender()
Inherited from Widget

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

startMeasurement

Method
startMeasurement()

Starts a new measurement for the active measurement widget.

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

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

measure();

when

Inherited
Method
when(callback, errback){Promise}
Inherited from Widget
Since: ArcGIS Maps SDK for JavaScript 4.19 Widget since 4.2, when added at 4.19.

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

Parameters
callback Function
optional

The function to call when the promise resolves.

errback Function
optional

The function to execute when the promise fails.

Returns
Type Description
Promise Returns a new promise for the result of callback.
Example
// Although this example uses the BasemapGallery widget, any class instance that is a promise may use when() in the same way
let bmGallery = new BasemapGallery();
bmGallery.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
});

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