Layer | References | ArcGIS Maps SDK for JavaScript

import Layer from "@arcgis/core/layers/Layer.js";

Inheritance:: Layer→Accessor

Subclasses:: BaseDynamicLayer, BaseElevationLayer, BaseTileLayer, BuildingSceneLayer, CSVLayer, CatalogLayer, DimensionLayer, ElevationLayer, FeatureLayer, GaussianSplatLayer, GeoJSONLayer, GeoRSSLayer, GraphicsLayer, GroupLayer, ImageryLayer, ImageryTileLayer, IntegratedMesh3DTilesLayer, IntegratedMeshLayer, KMLLayer, KnowledgeGraphLayer, LineOfSightLayer, LinkChartLayer, MapImageLayer, MapNotesLayer, MediaLayer, OGCFeatureLayer, WebTileLayer, ParquetLayer, PointCloudLayer, RouteLayer, SceneLayer, StreamLayer, SubtypeGroupLayer, TileLayer, UnknownLayer, UnsupportedLayer, VectorTileLayer, VideoLayer, ViewshedLayer, VoxelLayer, WCSLayer, WFSLayer, WMSLayer, WMTSLayer, CatalogDynamicGroupLayer, CatalogFootprintLayer, KnowledgeGraphSublayer

Since: ArcGIS Maps SDK for JavaScript 4.0

The layer is the most fundamental component of a Map. It is a collection of spatial data in the form of vector graphics, raster images, or 3D objects that represent real-world phenomena. Layers may contain discrete features that store vector data or continuous cells/pixels that store raster data.

In the case of vector-based layers, such as FeatureLayer and GraphicsLayer, each feature contained in the layer has a Geometry that allows it to be rendered as a Graphic with spatial context on the View. Features within the layer also contain data Graphic.attributes that provide additional information, which may be viewed in Popup windows and used for rendering the layer.

To create a layer you must use one of the subclasses of Layer or call the fromPortalItem() method. A few examples of layers include the following:

Roads and highways may be represented using linear features in a FeatureLayer
Land parcels can be displayed as polygons in a MapImageLayer
Satellite imagery may be displayed as tiled images in a TileLayer

Multiple layers may be added to the same map and overlaid on top of one another for visualization and analytical purposes. See Map for additional information regarding how to add layers to a map. Layers are rendered in the View with a LayerView.

In a broad sense, layers can be used for the following purposes:

Displaying location for geographic context
Querying data
Displaying categorical and/or numeric data
Analytics

All layer types inherit from Layer. To learn more about each layer type, comparing and contrasting their data sources and capabilities, see the table below.

Layers for querying, visualizing, analyzing data

Layer type	Data source	Data types	Features	Limitations
FeatureLayer	ArcGIS FeatureServer/MapServer, ArcGIS portal item, or client-side graphics	Points, polylines, polygons downloaded as vector graphics	Client-side processing, popup templates, renderers with 2D and 3D symbols, querying, editing (in a future release)	Limited number of features for display; may require large download depending on number of features
GraphicsLayer	Client-side graphics	Points, polylines, polygons displayed as vector graphics	No geometry schema. Points, polylines and polygons may be stored in a single layer.	No renderer nor popup templates; visualization and popup templates are handled on a graphic-by-graphic basis.
MapImageLayer	ArcGIS MapServer, ArcGIS portal item	Points, polylines, polygons, rasters exported in a single image	May contain nested sublayers. Server-side processing of renderers, popup templates, opacity, and labels for fast display of many features. May be used to display, query, and join data in registered workspaces	No editing support
SceneLayer	ArcGIS SceneServer, ArcGIS portal item	Point and multipatch geometries	Can display a large number of features on the client. Ideal for rendering 3D features	No 2D support; editing via associated feature layer
CSVLayer	CSV file	Points downloaded as vector graphics	Client-side processing, popup templates, renderers with 2D and 3D symbols	May require large download depending on the number of features
KMLLayer	KML file (.kml, .kmz), ArcGIS portal item	Points, polylines, polygons displayed as vector graphics	Display KML file in a map or webmap	No 3D support; requires access to utility service from ArcGIS.com or ArcGIS Enterprise
StreamLayer	ArcGIS StreamServer	Points downloaded as vector graphics	Downloads and updates feature locations in real time	N/A
ImageryLayer	ArcGIS ImageServer, ArcGIS portal item	Raster data exported as a single image	Client-side and server-side pixel filtering and rendering; popup templates; querying	N/A
ImageryTileLayer	ArcGIS ImageServer, ArcGIS portal item	Raster data exported as a single image	Client-side rendering; popup templates	N/A
GeoJSONLayer	GeoJSON	Points, polylines, polygons	Renderers, labels, editing, popups	Data must comply with the RFC 7946 specification which states that the coordinates are in SpatialReference WGS84
OGCFeatureLayer	OGC API - Features	Points, polylines, polygons	Renderers, labels, popups	Data must comply with the RFC 7946 specification which states that the coordinates are in SpatialReference WGS84
GeoRSSLayer	GeoRSS feed	Points, polylines, polygons	No geometry schema; popup templates	No 3D support; no support for renderers
DimensionLayer	ArcGIS WebScene	DimensionAnalysis	Client-side length dimensions	No 2D support
LineOfSightLayer	ArcGIS WebScene	LineOfSightAnalysis	Client-side line of sight analysis	No 2D support
ViewshedLayer	ArcGIS WebScene	ViewshedAnalysis	Client-side viewsheds	No 2D support
MapNotesLayer	ArcGIS WebMap, ArcGIS portal item	Points, polylines, polygons, text	Map Notes in a webmap	No 3D support; Read-only
WCSLayer	WCS service	Raster data exported as a single image	OGC specification	N/A
WFSLayer	WFS service, ArcGIS portal item	Points, multipoints, lines, polygons	OGC specification	Data must be GeoJSON format, only support version 2.0.0
WMSLayer	WMS service, ArcGIS portal item	Data exported as a single image	OGC specification	N/A
BaseDynamicLayer	ArcGIS MapServer, WMS service	Data exported as a single image	This class may be extended to create dynamic map layers	No 3D support; exported images cannot be cached in the browser
BuildingSceneLayer	ArcGIS SceneServer, ArcGIS portal item	Data is organized in BuildingGroupSublayers which contain BuildingComponentSublayers	Visualize complex digital models of buildings and interact with its components	No 2D support
SubtypeGroupLayer	ArcGIS FeatureServer/MapServer, ArcGIS portal item	Points, polylines, polygons downloaded as vector graphics	Contains a sublayer for each subtype in the feature service; each sublayer can be configured individually with its own renderer, popup, and labels	No 3D support; no editing support at the sublayer level
KnowledgeGraphLayer	ArcGIS KnowledgeGraphService	Data is organized in spatial and non-spatial sublayers. Spatial sublayers contain points, multipoints, lines and polygons	Contains a sublayer for each named type in the layer; each sublayer can be queried; spatial sublayers can be configured individually with their own renderer, popup, and labels	Can only be added to Map instance. Not a portal item, cannot be added to WebMap or MapViewer. Requires ArcGIS Enterprise 11.1

Layers for providing geographic context

Layer type	Data source	Data types	Features	Limitations
TileLayer	ArcGIS MapServer, ArcGIS portal item	Image tiles	Better performance for large datasets; querying features	No editing, client-side rendering, or popup templates; some schema limitations in 3D views.
BaseTileLayer	ArcGIS MapServer, ArcGIS portal item	Image tiles	This class may be extended to create custom tile layers	No editing, client-side rendering, or popup templates; some schema limitations in 3D views.
VectorTileLayer	ArcGIS portal item	Points, polylines, and polygons rendered as vector tiles	Features may be styled client-side and used as a tiled basemap	No editing, client-side rendering, or popup templates.
IntegratedMeshLayer or IntegratedMesh3DTilesLayer	ArcGIS SceneServer, ArcGIS portal item	triangulated mesh with texture	Displays 3D objects with a high level of detail	No 2D support
VoxelLayer	ArcGIS SceneServer, ArcGIS portal item	multidimensional voxel cubes	Displays multidimensional volumetric phenomena (e.g. underground models)	No 2D support
ElevationLayer	ArcGIS ImageServer, ArcGIS portal item	Tiled elevation mesh/surface	Renders elevation surfaces in 3D views	No 2D support
BaseElevationLayer	ArcGIS ImageServer, ArcGIS portal item	Tiled elevation mesh/surface	This class may be extended to create custom elevation layers	No 2D support
PointCloudLayer	ArcGIS SceneServer, ArcGIS portal item	Point clouds (e.g. collected from LiDAR)	Renderers; fast display of point clouds	No 2D support
OpenStreetMapLayer	OpenStreetMap tile services	Image tiles	Displays OpenStreetMap tiled content	N/A
WMTSLayer	WMTS tile services, ArcGIS portal item	Image tiles	OGC specification	N/A
WebTileLayer	non-ArcGIS, non-OGC, and non-OSM tile services	Image tiles	N/A	No editing, client-side rendering, or popup templates.
BingMapsLayer	Bing Spatial Data Service data	Image tiles	Displays Microsoft's Bing tiled content	Bing Maps key is required; three map styles are supported: `road`, `aerial`, and `hybrid`
MediaLayer	HTMLVideoElement, HTMLImageElement, or HTMLCanvasElement	Image/video element	Displays image and video elements in the map at specified geographic locations	GIF/APNG not currently
VideoLayer	ArcGIS VideoServer, ArcGIS portal item	Video	Displays a georeferenced video in the map	No 3D support

Other layers

Layer type	Data source	Data types	Features	Limitations
GroupLayer	Any combination of other layer types	N/A	Combines two or more layers into a single layer	N/A

See also

Properties

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

Property	Type	Class
`declaredClass` readonly inherited	`string`	Accessor
`fullExtent`	`Extent \| null \| undefined`
`id`	`string`
`listMode`	`LayerListMode`
`loaded` readonly	`boolean`
`loadError` readonly inherited	`EsriError \| null \| undefined`	LoadableMixin
`loadStatus` readonly inherited	`"not-loaded" \| "loading" \| "failed" \| "loaded"`	LoadableMixin
`loadWarnings` readonly inherited	`any[]`	LoadableMixin
`opacity`	`number`
`parent`	`Map \| Basemap \| Ground \| GroupLayer \| CatalogDynamicGroupLayer \| CatalogLayer \| null \| undefined`
`persistenceEnabled` readonly	`boolean`
`title`	`string \| null \| undefined`
`type` readonly	`LayerType`
`uid` readonly inherited	`string`	IdentifiableMixin
`visibilityTimeExtent`	`TimeExtent \| null \| undefined`
`visible`	`boolean`

declaredClass

readonlyinherited Property

Type: string

Inherited from: Accessor

Since: ArcGIS Maps SDK for JavaScript 4.7

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

fullExtent

autocast Property

Type: Extent | null | undefined

The full extent of the layer. By default, this is worldwide. This property may be used to set the extent of the view to match a layer's extent so that its features appear to fill the view. See the sample snippet below.

The fullExtent property is always null for GroupLayer.

Example

// Once the layer loads, set the view's extent to the layer's full extent
layer.when(function(){
  view.extent = layer.fullExtent;
});

id

Property

Type: string

The unique ID assigned to the layer. If not set by the developer, it is automatically generated when the layer is loaded.

listMode

Property

Type: LayerListMode

Indicates how the layer should display in the Layer List component. The possible values are listed below.

Value	Description
show	The layer is visible in the table of contents.
hide	The layer is hidden in the table of contents.
hide-children	If the layer is a GroupLayer, BuildingSceneLayer, KMLLayer, MapImageLayer, SubtypeGroupLayer, TileLayer, or WMSLayer, hide the children layers from the table of contents.

Default value: "show"

loaded

readonly Property

Type: boolean

Indicates whether the layer's resources have loaded. When true, all the properties of the object can be accessed.

Default value: false

loadError

readonlyinherited Property

Type: EsriError | null | undefined

Inherited from: LoadableMixin

The Error object returned if an error occurred while loading.

loadStatus

readonlyinherited Property

Type: "not-loaded" | "loading" | "failed" | "loaded"

Inherited from: LoadableMixin

Represents the status of a load() operation.

Value	Description
not-loaded	The object's resources have not loaded.
loading	The object's resources are currently loading.
loaded	The object's resources have loaded without errors.
failed	The object's resources failed to load. See loadError for more details.

Default value: "not-loaded"

loadWarnings

readonlyinherited Property

Type: any[]

Inherited from: LoadableMixin

A list of warnings which occurred while loading.

opacity

Property

Type: number

The opacity of the layer. This value can range between 1 and 0, where 0 is 100 percent transparent and 1 is completely opaque.

Known Limitations

In a 3D SceneView, modifying opacity is not supported for DimensionLayer, GaussianSplatLayer, IntegratedMesh3DTilesLayer, IntegratedMeshLayer, LineOfSightLayer, PointCloudLayer, ViewshedLayer, and VoxelLayer.

Default value: 1

Example

// Makes the layer 50% transparent
layer.opacity = 0.5;

parent

Property

Type: Map | Basemap | Ground | GroupLayer | CatalogDynamicGroupLayer | CatalogLayer | null | undefined

Since: ArcGIS Maps SDK for JavaScript 4.27

The parent to which the layer belongs.

persistenceEnabled

readonly Property

Type: boolean

Since: ArcGIS Maps SDK for JavaScript 4.28

When true, the layer can be persisted. This property only has an effect for layers that are part of the WebMap or WebScene spec.

Default value: false

title

Property

Type: string | null | undefined

The title of the layer used to identify it in places such as the Layer List component.

If the layer is loaded from a portal item, the title of the portal item will be used. If a layer is loaded as part of a webmap or a webscene, then the title of the layer as stored in the webmap/webscene will be used.

type

readonly Property

Type: LayerType

The layer type provides a convenient way to check the type of the layer without the need to import specific layer modules.

uid

readonlyinherited Property

Type: string

Inherited from: IdentifiableMixin

Since: ArcGIS Maps SDK for JavaScript 4.33

An automatically generated unique identifier assigned to the instance. The unique id is generated each time the application is loaded.

visibilityTimeExtent

autocast Property

Type: TimeExtent | null | undefined

Since: ArcGIS Maps SDK for JavaScript 4.30

Specifies a fixed time extent during which a layer should be visible. This property can be used to configure a layer that does not have time values stored in an attribute field to work with time. Once configured, the TimeSlider widget will display the layer within the set time extent. In the case that only one of the TimeExtent.start or TimeExtent.end date values are available, the layer remains visible indefinitely in the direction where there is no time value.

Aerial imagery can capture seasonal variations in vegetation, water bodies, and land use patterns. For example, in agricultural regions, aerial imageries taken during different growing seasons provide insights into crop health and productivity. Defining a fixed time extent on imageries from specific time periods provides temporal context and facilitates focused analysis based on specific time periods or events.

See also

Sample - GraphicsLayer with visibilityTimeExtent

visible

Property

Type: boolean

Indicates if the layer is visible in the View. When false, the layer may still be added to a Map instance that is referenced in a view, but its features will not be visible in the view.

Default value: true

Example

// The layer is no longer visible in the view
layer.visible = false;

// Watch for changes in the layer's visibility
// and set the visibility of another layer when it changes
reactiveUtils.watch(
  () => layer.visible,
  (visible) => {
    if (visible) {
      anotherLayer.visible = true;
    } else {
      anotherLayer.visible = false;
    }
  }
);

Methods

Method	Signature	Class
`fromArcGISServerUrl` static	`fromArcGISServerUrl(params: string \| FromArcGISServerUrlParameters): Promise<Layer>`
`fromPortalItem` static	`fromPortalItem(params: LayerFromPortalItemParameters): Promise<Layer>`
`cancelLoad` inherited	`cancelLoad(): this`	LoadableMixin
`createLayerView`	`createLayerView<T extends LayerView = LayerView>(view: View<T>, options?: AbortOptions): Promise<T>`
`destroy`	`destroy(): void`
`emit` inherited	`emit<Type extends EventNames<this>>(type: Type, event?: this["@eventTypes"][Type]): boolean`	EventedMixin
`fetchAttributionData`	`fetchAttributionData(): Promise<any>`
`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
`load` inherited	`load(options?: AbortOptions \| null \| undefined): Promise<this>`	LoadableMixin
`on` inherited	`on<Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle`	EventedMixin
`when` inherited	`when<TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> \| null \| undefined, onRejected?: OnRejectedCallback<TResult2> \| null \| undefined): Promise<TResult1 \| TResult2>`	EsriPromiseMixin

fromArcGISServerUrl

static Method

Signature: fromArcGISServerUrl (params: string | FromArcGISServerUrlParameters): Promise<Layer>

Creates a new layer instance from an ArcGIS Server URL. Depending on the URL, the returned layer type may be a BuildingSceneLayer, CatalogLayer, ElevationLayer, FeatureLayer, GroupLayer, ImageryLayer, ImageryTileLayer, IntegratedMeshLayer, KnowledgeGraphLayer, MapImageLayer, OrientedImageryLayer, PointCloudLayer, SceneLayer, StreamLayer, SubtypeGroupLayer, TileLayer, or VideoLayer.

This is useful when you work with various ArcGIS Server URLs, but you don't necessarily know which layer type(s) they create. This method creates the appropriate layer type for you. In case of a feature service or a scene service, when the URL points to the service and the service has multiple layers, the returned promise will resolve to a GroupLayer.

Beginning with version 4.17, it is possible to load tables from hosted feature services. This only applies to feature layers, and will successfully load if FeatureLayer.isTable returns true.

The following table details what is returned when loading specific URL types.

URL	Returns
Feature service with one layer	FeatureLayer where FeatureLayer.isTable returns `false`.
Feature service with one table	FeatureLayer where FeatureLayer.isTable returns `true`.
Feature service with more than one layer(s)/table(s)	GroupLayer with layers and tables.
Layers with type other than "Feature Layer" are discarded, e.g. Utility Network Layers	N/A

See also

FeatureLayer.isTable

Parameters

Parameter	Type	Description	Required
params	`string \| FromArcGISServerUrlParameters`	Input parameters for creating the layer.

Returns: Promise<Layer>
Returns a promise that resolves to the new Layer instance.

Examples

// This snippet shows how to add a feature layer from an ArcGIS Server URL
// Get an ArcGIS Server URL from a custom function
const arcgisUrl = getLayerUrl();

Layer.fromArcGISServerUrl({
  url: arcgisUrl,
  properties: {
    // set any layer properties here
    popupTemplate: new PopupTemplate()
  }
}).then(function(layer){
  // add the layer to the map
  map.add(layer);
});

// This snippet shows how to add a table from an ArcGIS Server URL
// Get an ArcGIS Server URL from a custom function
const arcgisUrl = getLayerUrl();

Layer.fromArcGISServerUrl({
  url: arcgisUrl
}).then(function(layer){
  // Load the table before it can be used
  layer.load().then(function() {
    // Check that it is the right type
    if (layer.isTable) {
      // Add table to map's tables collection
      map.tables.add(layer);
    }
  });
});

fromPortalItem

static Method

Signature: fromPortalItem (params: LayerFromPortalItemParameters): Promise<Layer>

Creates a new layer instance of the appropriate layer class from an ArcGIS Online or ArcGIS Enterprise portal item. If the item points to a feature service with multiple layers, then a GroupLayer is created. If the item points to a service with a single layer, then it resolves to a layer of the same type of class as the service.

Note

At version 4.29, MediaLayer can be loaded from portal items.
At version 4.28, GroupLayer and OrientedImageryLayer can be loaded from portal items.
At version 4.25, CSVLayer and GeoJSONLayer can be loaded from CSV and GeoJSON portal items respectively.
At version 4.17, it is possible to load tables from feature service items hosted in ArcGIS Online and ArcGIS Enterprise. This only applies to feature layers, and will successfully load if FeatureLayer.isTable returns true.

The following table details what is returned when loading specific item types.

Item(s)	Returns
Feature service with one layer	FeatureLayer where FeatureLayer.isTable returns `false`.
Feature service with one table	FeatureLayer where FeatureLayer.isTable returns `true`.
Feature service with more than one layer(s)/table(s)	GroupLayer with layers and tables.
Feature collection with one layer	FeatureLayer where FeatureLayer.isTable returns `false`.
Feature collection with one table	FeatureLayer where FeatureLayer.isTable returns `true`.
Feature collection with more than one layer(s)/table(s)	GroupLayer with layers and tables.

Known Limitations

This method does not currently work with OGCFeatureServer portal items.

See also

Parameters

Parameter	Type	Description	Required
params	`LayerFromPortalItemParameters`	The parameters for loading the portal item.

Returns: Promise<Layer>
Returns a promise which resolves to the new layer instance.

Examples

// Create a layer from a specified portal item and add to the map
Layer.fromPortalItem({
  portalItem: {  // autocasts new PortalItem()
    id: "8444e275037549c1acab02d2626daaee"
  }
}).then(function(layer){
  // add the layer to the map
  map.add(layer);
});

// Create a table from a specified portal item and add it to the map's tables collection
Layer.fromPortalItem({
  portalItem: { // autocasts new PortalItem()
    id: "123f4410054b43d7a0bacc1533ceb8dc" // This is a hosted table stored in a feature service
  }
}).then(function(layer) {
  // Necessary to load the table in order for it to be read correctly
  layer.load().then(function() {
    // Confirm this reads as a table
    if (layer.isTable) {
      // Add the new table to the map's table collection
      map.tables.add(layer);
    }
  });
});

cancelLoad

inherited Method

Signature: cancelLoad (): this

Inherited from: LoadableMixin

Cancels a load() operation if it is already in progress.

Returns: this

createLayerView

Method

Signature: createLayerView <T extends LayerView = LayerView>(view: View<T>, options?: AbortOptions): Promise<T>

Type parameters: <T extends LayerView = LayerView>

Called by the views, such as MapView and SceneView, when the layer is added to the Map.layers collection and a layer view must be created for it. This method is used internally and there is no use case for invoking it directly.

See also

Sample - Custom WebGL layer view

Parameters

Parameter	Type	Description	Required
view	`View`	The parent view.
options	`AbortOptions`	An object specifying additional options. See the object specification table below for the required properties of this object.

Returns: Promise
Resolves with a LayerView instance.

destroy

Method

Signature: destroy (): void

Since: ArcGIS Maps SDK for JavaScript 4.17

Destroys the layer and any associated resources (including its portalItem, if it is a property on the layer). The layer can no longer be used once it has been destroyed.

The destroyed layer will be removed from its parent object like Map, WebMap, WebScene, Basemap, Ground, or GroupLayer.

See also

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

Since: ArcGIS Maps SDK for JavaScript 4.5

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

fetchAttributionData

Method

Signature: fetchAttributionData (): Promise<any>

Fetches custom attribution data for the layer when it becomes available.

Returns: Promise<any>
Resolves to an object containing custom attribution data for the layer.

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.

load

inherited Method

Signature: load (options?: AbortOptions | null | undefined): Promise<this>

Inherited from: LoadableMixin

Loads the resources referenced by this class. This method automatically executes for a View and all of the resources it references in Map if the view is constructed with a map instance.

This method must be called by the developer when accessing a resource that will not be loaded in a View.

The load() method only triggers the loading of the resource the first time it is called. The subsequent calls return the same promise.

It's possible to provide a signal to stop being interested into a Loadable instance load status. When the signal is aborted, the instance does not stop its loading process, only cancelLoad() can abort it.

Parameters

Parameter	Type	Description	Required
options	`AbortOptions \| null \| undefined`	Additional options.

Returns: Promise<this>
Resolves when the resources have loaded.

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);
});

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

Since: ArcGIS Maps SDK for JavaScript 4.6

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
});

Events

Name	Type
`layerview-create`	CustomEvent<LayerLayerviewCreateEvent>
`layerview-create-error`	CustomEvent<LayerLayerviewCreateErrorEvent>
`layerview-destroy`	CustomEvent<LayerLayerviewDestroyEvent>

layerview-create

Event

layerview-create: CustomEvent<LayerLayerviewCreateEvent>

Fires after the layer's LayerView is created and rendered in a view.

See also

View.whenLayerView()

Example

// This function will fire each time a layer view is created for this
// particular view.
layer.on("layerview-create", function(event){
  // The LayerView for the layer that emitted this event
  event.layerView;
});

layerview-create-error

Event

layerview-create-error: CustomEvent<LayerLayerviewCreateErrorEvent>

Fires when an error emits during the creation of a LayerView after a layer has been added to the map.

See also

View.whenLayerView()

Example

// This function fires when an error occurs during the creation of the layer's layerview
layer.on("layerview-create-error", function(event) {
  console.error("LayerView failed to create for layer with the id: ", layer.id, " in this view: ", event.view);
});

layerview-destroy

Event

layerview-destroy: CustomEvent<LayerLayerviewDestroyEvent>

Fires after the layer's LayerView is destroyed and no longer renders in a view.

Type definitions

FromArcGISServerUrlParameters

Type definition

url

Property

Type: string

The ArcGIS Server URL used to create the layer.

properties

Property

Type: Record<string, unknown> | undefined

Set any of the layer's properties here for constructing the layer instance (e.g. popupTemplate, renderer, etc.).

LayerFromPortalItemParameters

Type definition

portalItem

Property

Type: PortalItem

The object representing an ArcGIS Online or ArcGIS Enterprise portal item from which to load the layer.

LayerLayerviewCreateEvent

Type definition

view

Property

Type: View

The view in which the layerView was created.

layerView

Property

Type: LayerView

The LayerView rendered in the view representing the layer in layer.

LayerLayerviewCreateErrorEvent

Type definition

view

Property

Type: View

The view that failed to create a layerview for the layer emitting this event.

error

Property

Type: Error

An error object describing why the layer view failed to create.

LayerLayerviewDestroyEvent

Type definition

view

Property

Type: View

The view in which the layerView was destroyed.

layerView

Property

Type: LayerView

The destroyed LayerView representing the layer.