AreaMeasurement3D | API Reference | ArcGIS Maps SDK for JavaScript 4.30

The AreaMeasurement3D widget calculates and displays the area and perimeter of a polygon. This widget can be used in a SceneView to measure the area and perimeter of a polygon.

How the area and perimeter are computed depends on the scene’s spatial reference and the length of the measured perimeter.

In geographic coordinate systems (GCS) and in Web Mercator:

If the measurement’s perimeter is below 100 km, they are computed in a Euclidean manner, in an ECEF coordinate system (or equivalent on other planets).
If the perimeter is above 100 km, they are computed geodetically, and the visualization takes the curvature of the planet into consideration.

In projected coordinate systems (PCS), apart from Web Mercator, the area and perimeter are always calculated in a Euclidean manner (in their respective PCS).

The area may be visualized and calculated in two ways:

If all the vertices are more or less coplanar (aligning onto a horizontal or a sloped plane), the area and perimeter are projected to that plane. Also, the measurements are computed on that plane.
If the vertices have varying z-values and they create a non-planar surface, the visualization and the measurements show the area and perimeter that are projected to a horizontal plane.

area-measurement-3d-types

When the widget is active, a horizontal "laser" line is drawn which indicates the height at the current mouse position. This line can help in analyzing the heights of objects relative to each other and the terrain.

This widget is designed to work with 3D SceneViews. For measurements with 2D MapViews, use AreaMeasurement2D.

Things to consider:

Snapping is enabled by default. This can be temporarily disabled by holding the CTRL key.
Layer types currently supported for snapping are: FeatureLayer, GraphicsLayer, GeoJSONLayer, WFSLayer, CSVLayer, 3D Object SceneLayer, and BuildingSceneLayer.

See also

Example

let measurementWidget = new AreaMeasurement3D({
  view: view
});

view.ui.add(measurementWidget, "top-right");

Constructors

AreaMeasurement3D Constructor new AreaMeasurement3D(properties)

Parameter

properties Object

optional

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

Example

// typical usage
let measurementWidget = new AreaMeasurement3D({
  view: view
});

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.

Show inherited properties

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Type	Summary	Class
AreaMeasurementAnalysis	The area measurement analysis object being created or modified by the widget.	AreaMeasurement3D
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.	AreaMeasurement3D
String	The unique ID assigned to the widget when the widget is created.	Widget
String	The widget's default label.	AreaMeasurement3D
SystemOrAreaUnit	Unit system (imperial, metric) or specific unit used for displaying the area values.	AreaMeasurement3D
SystemOrAreaUnit []	List of available units and unit systems (imperial, metric) for displaying the area values.	AreaMeasurement3D
SceneView	A reference to the SceneView.	AreaMeasurement3D
AreaMeasurement3DViewModel	The view model for this widget.	AreaMeasurement3D
Boolean	Indicates whether the widget is visible.	Widget

Property Details

analysis Property analysis AreaMeasurementAnalysisautocastreadonly Since: ArcGIS Maps SDK for JavaScript 4.23 AreaMeasurement3D since 4.7, analysis added at 4.23.

The area measurement analysis object being created or modified by the widget. This property is an alias for AreaMeasurement3DViewModel.analysis.

This property can be set during widget construction, to provide an existing analysis to the widget for modification. Properties on the analysis can also be modified once it's assigned to the widget.

If no analysis is provided during widget construction, the widget automatically creates its own analysis and adds it to the view. In this case, the analysis will also be automatically removed from the view when the widget is destroyed.

See also

AreaMeasurement3DViewModel.analysis

Example

// Construct an area measurement analysis object outside of the widget
const analysis = new AreaMeasurementAnalysis({
  geometry: {
    type: "polygon", // autocasts as new Polygon()
    rings: [
      [-73.9817, 40.7681],
      [-73.9582, 40.8005],
      [-73.9495, 40.7968],
      [-73.9730, 40.7644],
      [-73.9817, 40.7681]
    ]
  }
});

// Ensure that the analysis is added to the view
view.analyses.add(analysis);

// Frame the analysis in the view
view.goTo(analysis.extent);

// Pass the analysis object as a constructor parameter to modify it using the widget
const viewModel = new AreaMeasurement3D({
  analysis: analysis,
  view: view
});

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 AreaMeasurement3D since 4.7, 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:"measure-area"

See also

Calcite Icon Search

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.

unit Property unit SystemOrAreaUnit Since: ArcGIS Maps SDK for JavaScript 4.8 AreaMeasurement3D since 4.7, unit added at 4.8.

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

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.

view Property view SceneView

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

viewModel Property viewModel AreaMeasurement3DViewModelautocast

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 AreaMeasurement3DViewModel class to access all properties and methods on the widget.

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

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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
	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
	Executes after widget is ready for rendering.	Widget
	Removes a group of handles owned by the object.	Accessor
Object	This method is implemented by subclasses for rendering.	Widget
	Renders widget to the DOM immediately.	Widget
	Schedules widget rendering.	Widget
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 dynamicClasses = {
    [css.flip]: this.flip,
    [css.primary]: this.primary
  };

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

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

type String|String []

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

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 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

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

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
});