Layer | API Reference | ArcGIS Maps SDK for JavaScript 4.31

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 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 Layer.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

Property Overview

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

Show inherited properties

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Type	Summary	Class
String	The name of the class.	Accessor
Extent\|null\|undefined	The full extent of the layer.	Layer
String	The unique ID assigned to the layer.	Layer
String	Indicates how the layer should display in the LayerList widget.	Layer
Error	The Error object returned if an error occurred while loading.	Layer
String	Represents the status of a load operation.	Layer
Object []	A list of warnings which occurred while loading.	Layer
Boolean	Indicates whether the layer's resources have loaded.	Layer
Number	The opacity of the layer.	Layer
Map\|Basemap\|Ground\|GroupLayer\|CatalogDynamicGroupLayer\|CatalogLayer	The parent to which the layer belongs.	Layer
Boolean	When `true`, the layer can be persisted.	Layer
String\|null\|undefined	The title of the layer used to identify it in places such as the LayerList widget.	Layer
String	The layer type provides a convenient way to check the type of the layer without the need to import specific layer modules.	Layer
TimeExtent\|null\|undefined	Specifies a fixed time extent during which a layer should be visible.	Layer
Boolean	Indicates if the layer is visible in the View.	Layer

Property Details

declaredClass Inherited Property declaredClass Stringreadonly Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.7 Accessor since 4.0, declaredClass added at 4.7.

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

fullExtent Property fullExtent Extent |null |undefinedautocast

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.

Example

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

id Property id 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 listMode String

Indicates how the layer should display in the LayerList widget. 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, TileLayer or WMSLayer, hide the children layers from the table of contents.

Possible Values:"show" |"hide" |"hide-children"

Default Value:"show"

loadError Property loadError Errorreadonly

The Error object returned if an error occurred while loading.

Default Value:null

loadStatus Property loadStatus Stringreadonly

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.

Possible Values:"not-loaded" |"loading" |"failed" |"loaded"

Default Value:"not-loaded"

loadWarnings Property loadWarnings Object[]readonly

A list of warnings which occurred while loading.

loaded Property loaded Booleanreadonly

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

Default Value:false

opacity Property opacity 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.

Default Value:1

Example

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

The parent to which the layer belongs.

persistenceEnabled Property persistenceEnabled Boolean Since: ArcGIS Maps SDK for JavaScript 4.28 Layer since 4.0, persistenceEnabled added at 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 title String |null |undefined

The title of the layer used to identify it in places such as the LayerList widget.

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 Property type Stringreadonly

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

visibilityTimeExtent Property visibilityTimeExtent TimeExtent |null |undefinedautocast Since: ArcGIS Maps SDK for JavaScript 4.30 Layer since 4.0, visibilityTimeExtent added at 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 start or 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.

Default Value:null

See also

Sample - GraphicsLayer with visibilityTimeExtent

visible Property visible 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;
    }
  }
);

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
	Cancels a load() operation if it is already in progress.	Layer
Promise<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.	Layer
	Destroys the layer and any associated resources (including its portalItem, if it is a property on the layer).	Layer
Boolean	Emits an event on the instance.	Layer
Promise<Object>	Fetches custom attribution data for the layer when it becomes available.	Layer
Promise<Layer>	Creates a new layer instance from an ArcGIS Server URL.	Layer
Promise<Layer>	Creates a new layer instance of the appropriate layer class from an ArcGIS Online or ArcGIS Enterprise portal item.	Layer
Boolean	Indicates whether there is an event listener on the instance that matches the provided event name.	Layer
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).	Layer
Boolean	`isRejected()` may be used to verify if creating an instance of the class is rejected.	Layer
Boolean	`isResolved()` may be used to verify if creating an instance of the class is resolved.	Layer
Promise	Loads the resources referenced by this class.	Layer
Object	Registers an event handler on the instance.	Layer
	Removes a group of handles owned by the object.	Accessor
Promise	`when()` may be leveraged once an instance of the class is created.	Layer

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.

cancelLoad Method cancelLoad()

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

createLayerView Method createLayerView(view, options){Promise<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.

Parameters

view *

The parent view.

options Object

optional

An object specifying additional options. See the object specification table below for the required properties of this object.

Specification

signal AbortSignal

optional

A signal to abort the creation of the layerview.

Returns

Type	Description
Promise<LayerView>	Resolves with a LayerView instance.

See also

Sample - Custom WebGL layer view

destroy Method destroy() Since: ArcGIS Maps SDK for JavaScript 4.17 Layer since 4.0, destroy added at 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

emit Method emit(type, event){Boolean} Since: ArcGIS Maps SDK for JavaScript 4.5 Layer since 4.0, emit added at 4.5.

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

fetchAttributionData Method fetchAttributionData(){Promise<Object>}

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

Returns

Type	Description
Promise<Object>	Resolves to an object containing custom attribution data for the layer.

fromArcGISServerUrl Method fromArcGISServerUrl(params){Promise<Layer>}static

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, IntegratedMesh3DTilesLayer, 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 isTable returns `false`.
Feature service with one table	FeatureLayer where 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

Parameters

Specification

params Object

Input parameters for creating the layer.

Specification

url String

The ArcGIS Server URL used to create the layer.

properties Object

optional

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

Returns

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

See also

isTable

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 Method fromPortalItem(params){Promise<Layer>}static

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 `isTable` returns `false`.
Feature service with one table	FeatureLayer where `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 `isTable` returns `false`.
Feature collection with one table	FeatureLayer where `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.

Parameters

params Object

The parameters for loading the portal item.

Specification

portalItem PortalItem

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

Returns

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

See also

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);
    }
  });
});

hasEventListener Method hasEventListener(type){Boolean}

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 Method 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

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

isRejected Method 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

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

isResolved Method 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

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

load Method load(signal){Promise}

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.

Parameter

signal AbortSignal

optional

Signal object that can be used to abort the asynchronous task. The returned promise will be rejected with an Error named AbortError when an abort is signaled. See also AbortController for more information on how to construct a controller that can be used to deliver abort signals.

Returns

Type	Description
Promise	Resolves when the resources have loaded.

on Method on(type, listener){Object}

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);
});

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");

when Method when(callback, errback){Promise} Since: ArcGIS Maps SDK for JavaScript 4.6 Layer since 4.0, when added at 4.6.

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` 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
});

Event Overview

Type	Summary	Class
{view: View,layerView: LayerView}	Fires after the layer's LayerView is created and rendered in a view.	Layer
{view: View,error: Error}	Fires when an error emits during the creation of a LayerView after a layer has been added to the map.	Layer
{view: View,layerView: LayerView}	Fires after the layer's LayerView is destroyed and no longer renders in a view.	Layer

Event Details

layerview-create Event layerview-create

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

Properties

view View

The view in which the layerView was created.

layerView LayerView

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

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

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

Properties

view View

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

error Error

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

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

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

Properties: view View

The view in which the layerView was destroyed.

layerView LayerView

The destroyed LayerView representing the layer.