import AreaMeasurement3D from "@arcgis/core/widgets/AreaMeasurement3D.js";const AreaMeasurement3D = await $arcgis.import("@arcgis/core/widgets/AreaMeasurement3D.js");- Inheritance:
- AreaMeasurement3D→
Widget<AreaMeasurement3DProperties>→ Accessor
- Since
- ArcGIS Maps SDK for JavaScript 4.7
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.
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 (except Mesh geometries),
GeoJSONLayer, WFSLayer, CSVLayer,
3D Object SceneLayer, and BuildingSceneLayer.
- See also
Example
let measurementWidget = new AreaMeasurement3D({ view: view});
view.ui.add(measurementWidget, "top-right");Constructors
Constructor
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
| properties | | |
Example
// typical usagelet measurementWidget = new AreaMeasurement3D({ view: view});Properties
| Property | Type | Class |
|---|---|---|
| | ||
container inherited | HTMLElement | null | undefined | |
declaredClass readonly inherited | ||
destroyed readonly inherited | ||
Icon["icon"] | | |
id inherited | ||
| | ||
| | ||
| | ||
| | ||
| | ||
visible inherited |
analysis
- Since
- ArcGIS Maps SDK for JavaScript 4.23
The area measurement analysis object being created or modified by the widget. This property is an alias for AreaMeasurement3DViewModel.analysis.
If no analysis is provided, 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.
Example
// Construct an area measurement analysis object outside of the widgetconst 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 viewview.analyses.add(analysis);
// Frame the analysis in the viewview.goTo(analysis.extent);
// Pass the analysis object as a constructor parameter to modify it using the widgetconst viewModel = new AreaMeasurement3D({ analysis: analysis, view: view}); container
- Type
- HTMLElement | null | undefined
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 containerconst basemapGallery = new BasemapGallery({ view: view, container: document.createElement("div")});
// Add the widget to the top-right corner of the viewview.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 viewview.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 UIconst basemapGallery = new BasemapGallery({ view: view});
// Add the widget to the top-right corner of the viewview.ui.add(basemapGallery, { position: "top-right"}); icon
- 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).
- Default value
- "measure-area"
unit
- Type
- SystemOrAreaUnit
- Since
- ArcGIS Maps SDK for JavaScript 4.8
Unit system (imperial, metric) or specific unit used for displaying the area values. Possible values are listed in unitOptions.
unitOptions
- Type
- 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.
viewModel
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
- Type
- boolean
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 viewwidget.visible = false;Methods
| Method | Signature | Class |
|---|---|---|
classes inherited | classes(...classNames: ((string | null | undefined) | ((string[] | Record<string, boolean>) | null | undefined) | false | null | undefined)[]): string | |
destroy inherited | destroy(): void | |
emit inherited | emit<Type extends EventNames<this>>(type: Type, event?: this["@eventTypes"][Type]): boolean | |
hasEventListener inherited | hasEventListener<Type extends EventNames<this>>(type: Type): boolean | |
isFulfilled inherited | isFulfilled(): boolean | |
isRejected inherited | isRejected(): boolean | |
isResolved inherited | isResolved(): boolean | |
on inherited | on<Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle | |
postInitialize inherited | postInitialize(): void | |
render inherited | render(): any | null | |
renderNow inherited | renderNow(): void | |
scheduleRender inherited | scheduleRender(): void | |
when inherited | when<TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> | null | undefined, onRejected?: OnRejectedCallback<TResult2> | null | undefined): Promise<TResult1 | TResult2> |
classes
- Signature
-
classes (...classNames: ((string | null | undefined) | ((string[] | Record<string, boolean>) | null | undefined) | false | null | undefined)[]): string
A utility method used for building the value for a widget's class property.
This aids in simplifying css class setup.
Parameters
- 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)} /> );} emit
- Signature
-
emit <Type extends EventNames<this>>(type: Type, event?: this["@eventTypes"][Type]): boolean
- Type parameters
- <Type extends EventNames<this>>
Emits an event on the instance. This method should only be used when creating subclasses of this class.
hasEventListener
- Signature
-
hasEventListener <Type extends EventNames<this>>(type: Type): boolean
- Type parameters
- <Type extends EventNames<this>>
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
- Signature
-
isFulfilled (): boolean
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
- Signature
-
isRejected (): boolean
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
- Signature
-
isResolved (): boolean
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
- Signature
-
on <Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle
- Type parameters
- <Type extends EventNames<this>>
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);}); when
- Signature
-
when <TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> | null | undefined, onRejected?: OnRejectedCallback<TResult2> | null | undefined): Promise<TResult1 | TResult2>
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 | The function to execute when the promise fails. | |
- Returns
- Promise<TResult1 | TResult2>
Returns a new promise for the result of
onFulfilledthat 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 waylet 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});