BaseElevationLayer | References | ArcGIS Maps SDK for JavaScript

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

Inheritance:: BaseElevationLayer→Layer→Accessor

Since: ArcGIS Maps SDK for JavaScript 4.4

BaseElevationLayer is intended to be extended for creating custom elevation layers. You create a custom ElevationLayer by calling Accessor.createSubclass() on the BaseElevationLayer.

If the new layer needs to fetch and prepare resources, you can initialize properties asynchronously prior to loading the layer. This is handled in the load() method. This method is called once, either by you or by the view, when the layer is about to be displayed. In the body of the method you can call addResolvingPromise() to add a promise that has to be resolved before the layer is considered loaded.

You must overwrite the logic in the fetchTile() method to return the values of the custom elevation data. This can be done to exaggerate actual elevation values or for mapping thematic data as an elevation layer. When transforming the values of the elevation data it is recommended to keep the no data value unchanged.

const ExaggeratedElevationLayer = BaseElevationLayer.createSubclass({
  load: function() {
    // add loadable dependencies here and include
    // their returned promises in the
    // addResolvingPromise() method
    this._elevation = new ElevationLayer({
      url: "//elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"
    });
    this.addResolvingPromise(this._elevation.load());
  },

  fetchTile: function(level, row, col, options) {
    // must resolve to an object with the following properties:
    // values <number[]>: an array of elevation values for each pixel
    // width <number>: the width of the tile in pixels
    // height <number>: the height of the tile in pixels
    // noDataValue <number>: value of pixels where no elevation data is present
    return this._elevation.fetchTile(level, row, col, options).then(function(data) {
      let exaggeration = this.exaggeration;
      // `data` is an object that contains the width of the tile in pixels,
      // the height of the tile in pixels, and the values of each pixel
      for (let i = 0; i < data.values.length; i++) {
         // each value represents an elevation sample for the
         // given pixel position in the tile
         // check if the value is a no data value
         if (data.values[i] !== data.noDataValue) {
           // multiply the elevation value by the exaggeration value
           data.values[i] *= exaggeration;
         }
      }
      return data;
    }.bind(this))
  }
});

Once the layer is created, you must add it to the layers of the Map.ground property and add the map to a SceneView instance.

let map = new Map({
  basemap: "satellite",
  ground: {
    layers: [ new ExaggeratedElevationLayer() ]
  }
});
sceneView.map = map;

See also

Constructors

Constructor

Parameters

Parameter	Type	Description	Required
properties	`BaseElevationLayerProperties`

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

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` inherited	`Extent \| null \| undefined`	Layer
`id` inherited	`string`	Layer
`listMode` inherited	`LayerListMode`	Layer
`loaded` readonly inherited	`boolean`	Layer
`loadError` readonly inherited	`EsriError \| null \| undefined`	LoadableMixin
`loadStatus` readonly inherited	`"not-loaded" \| "loading" \| "failed" \| "loaded"`	LoadableMixin
`loadWarnings` readonly inherited	`any[]`	LoadableMixin
`maxScale` inherited	`number`	ScaleRangeLayer
`minScale` inherited	`number`	ScaleRangeLayer
`opacity` inherited	`number`	Layer
`parent` inherited	`Map \| Basemap \| Ground \| GroupLayer \| CatalogDynamicGroupLayer \| CatalogLayer \| null \| undefined`	Layer
`persistenceEnabled` readonly inherited	`boolean`	Layer
`spatialReference`	`SpatialReference`
`tileInfo`	`TileInfo`
`title` inherited	`string \| null \| undefined`	Layer
`type` readonly	`"base-elevation"`
`uid` readonly inherited	`string`	IdentifiableMixin
`visibilityTimeExtent` inherited	`TimeExtent \| null \| undefined`	Layer
`visible` inherited	`boolean`	Layer

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 inherited Property

Type: Extent | null | undefined

Inherited from: Layer

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

inherited Property

Type: string

Inherited from: Layer

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

listMode

inherited Property

Type: LayerListMode

Inherited from: Layer

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

readonlyinherited Property

Type: boolean

Inherited from: Layer

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.

maxScale

inherited Property

Type: number

Inherited from: ScaleRangeLayer

The maximum scale (most zoomed in) at which the layer is visible in the view. If the map is zoomed in beyond this scale, the layer will not be visible. A value of 0 means the layer does not have a maximum scale. The maxScale value should always be smaller than the minScale value, and greater than or equal to the service specification.

Default value: 0

Examples

// The layer will not be visible when the view is zoomed in beyond a scale of 1:1,000
layer.maxScale = 1000;

// The layer's visibility is not restricted to a maximum scale.
layer.maxScale = 0;

minScale

inherited Property

Type: number

Inherited from: ScaleRangeLayer

The minimum scale (most zoomed out) at which the layer is visible in the view. If the map is zoomed out beyond this scale, the layer will not be visible. A value of 0 means the layer does not have a minimum scale. The minScale value should always be larger than the maxScale value, and lesser than or equal to the service specification.

Default value: 0

Examples

// The layer will not be visible when the view is zoomed out beyond a scale of 1:3,000,000
layer.minScale = 3000000;

// The layer's visibility is not restricted to a minimum scale.
layer.minScale = 0;

opacity

inherited Property

Type: number

Inherited from: Layer

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

inherited Property

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

Inherited from: Layer

Since: ArcGIS Maps SDK for JavaScript 4.27

The parent to which the layer belongs.

persistenceEnabled

readonlyinherited Property

Type: boolean

Inherited from: Layer

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

spatialReference

autocast Property

Type: SpatialReference

The spatial reference of the layer.

Default value: {@link geometry/SpatialReference#WebMercator}

tileInfo

autocast Property

Type: TileInfo

The tiling scheme information for the layer.

title

inherited Property

Type: string | null | undefined

Inherited from: Layer

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: "base-elevation"

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 inherited Property

Type: TimeExtent | null | undefined

Inherited from: Layer

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

inherited Property

Type: boolean

Inherited from: Layer

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` inherited static	`fromArcGISServerUrl(params: string \| FromArcGISServerUrlParameters): Promise<Layer>`	Layer
`fromPortalItem` inherited static	`fromPortalItem(params: LayerFromPortalItemParameters): Promise<Layer>`	Layer
`addResolvingPromise`	`addResolvingPromise<U, V extends EsriPromiseMixin>(promiseToLoad: PromiseLike<U> \| V \| PromiseLike<V> \| null \| undefined): void`
`cancelLoad` inherited	`cancelLoad(): this`	LoadableMixin
`createElevationSampler`	`createElevationSampler(extent: Extent, options?: CreateElevationSamplerOptions): Promise<ElevationSampler>`
`createLayerView` inherited	`createLayerView<T extends LayerView = LayerView>(view: View<T>, options?: AbortOptions): Promise<T>`	Layer
`destroy` inherited	`destroy(): void`	Layer
`emit` inherited	`emit<Type extends EventNames<this>>(type: Type, event?: this["@eventTypes"][Type]): boolean`	EventedMixin
`fetchAttributionData` inherited	`fetchAttributionData(): Promise<any>`	Layer
`fetchTile`	`fetchTile(level: number, row: number, column: number, options?: FetchTileOptions): Promise<ElevationTileData>`
`getTileBounds`	`getTileBounds(level: number, row: number, column: number, out?: [ number, number, number, number ]): [ number, number, number, number ]`
`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
`queryElevation`	`queryElevation(geometry: Point, options?: ElevationQueryOptions): Promise<ElevationQueryResult<Point>>`
`queryElevation`	`queryElevation(geometry: Multipoint, options?: ElevationQueryOptions): Promise<ElevationQueryResult<Multipoint>>`
`queryElevation`	`queryElevation(geometry: Polyline, options?: ElevationQueryOptions): Promise<ElevationQueryResult<Polyline>>`
`queryElevation`	`queryElevation(geometry: ElevationQueryGeometry, options?: ElevationQueryOptions): Promise<ElevationQueryResult<ElevationQueryGeometry>>`
`when` inherited	`when<TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> \| null \| undefined, onRejected?: OnRejectedCallback<TResult2> \| null \| undefined): Promise<TResult1 \| TResult2>`	EsriPromiseMixin

fromArcGISServerUrl

inheritedstatic Method

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

Inherited from: 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

inheritedstatic Method

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

Inherited from: 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);
    }
  });
});

addResolvingPromise

Method

Signature: addResolvingPromise <U, V extends EsriPromiseMixin>(promiseToLoad: PromiseLike<U> | V | PromiseLike<V> | null | undefined): void

Type parameters: <U, V extends EsriPromiseMixin>

Adds a promise to the layer's loadable chain. This is typically used in the load() method to ensure that all loadable resources required for the layer to function are loaded prior to this layer resolving and becoming loaded.

Parameters

Parameter	Type	Description	Required
promiseToLoad	`PromiseLike \| V \| PromiseLike \| null \| undefined`	A promise that must resolve for the layer to resolve and move from the `loading` status to being loaded.

Returns: void

Example

// the _elevationLayer must load() prior to the ExaggeratedElevationLayer
// resolving and moving to the "loaded" status
const ExaggeratedElevationLayer = BaseElevationLayer.createSubclass({
  load: function() {
    this._elevationLayer = new ElevationLayer({
      url: "//elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"
    });

    this.addResolvingPromise(this._elevationLayer.load());
  }
});

cancelLoad

inherited Method

Signature: cancelLoad (): this

Inherited from: LoadableMixin

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

Returns: this

createElevationSampler

Method

Signature: createElevationSampler (extent: Extent, options?: CreateElevationSamplerOptions): Promise<ElevationSampler>

Since: ArcGIS Maps SDK for JavaScript 4.12

Creates an elevation sampler for the given Extent by querying the service layer for elevation data and caching it so values may be sampled quickly afterwards.

The resolution of the cached data can be set using the demResolution option. In many cases, auto demResolution can be used to get high quality elevation samples without the need to know exactly where the data in the service is located. This is particularly useful for services which combine elevation data from many sources (such as the world elevation service). If more control, or higher quality samples are required, use either finest-contiguous or a fixed {number} resolution.

Parameters

Parameter	Type	Description	Required
extent	`Extent`	The extent for which to create the sampler.
options	`CreateElevationSamplerOptions`	Additional query options.

Returns: Promise<ElevationSampler>
An elevation sampler.

createLayerView

inherited Method

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

Type parameters: <T extends LayerView = LayerView>

Inherited from: Layer

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

inherited Method

Signature: destroy (): void

Inherited from: Layer

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

inherited Method

Signature: fetchAttributionData (): Promise<any>

Inherited from: Layer

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.

fetchTile

Method

Signature: fetchTile (level: number, row: number, column: number, options?: FetchTileOptions): Promise<ElevationTileData>

Fetches a tile at the given level, row, and column present in the view. This method must be overwritten to display custom elevation values in the Map.ground. Note that this method must return a promise that resolves to an object with the properties defined in ElevationTileData.

See the following samples for examples of how to overwrite this method:

Parameters

Parameter	Type	Description
level	`number`	The level of detail of the tile to fetch.
row	`number`	The row (y) position of the tile to fetch.
column	`number`	The column (x) position of the tile to fetch.
options	`FetchTileOptions`	Optional settings for the tile request.

Returns: Promise<ElevationTileData>
Resolves to an instance of ElevationTileData.

getTileBounds

Method

Signature: getTileBounds (level: number, row: number, column: number, out?: [ number, number, number, number ]): [ number, number, number, number ]

Returns the bounds of the tile as an array of four numbers that can be readily converted to an Extent object. See the table in the returns section below for more details about the values returned by this method.

This function can be used inside fetchTile() so you can get the bounds of the current tile, convert it to an extent object, and request the desired data for the given extent. See the Custom ElevationLayer: Thematic data as elevation sample for an example of how this method works.

See also

Parameters

Parameter	Type	Description
level	`number`	The level of detail (LOD) of the tile.
row	`number`	The tile's row (y) position in the dataset.
column	`number`	The tiles column (x) position in the dataset.
out	`[ number, number, number, number ]`	Array for storing the tile bounds or extent.

Returns

[ number, number, number, number ]

Returns an array representing the tile bounds or extent. The array has four items, each representing one bound of the extent. The values of each item are described in the table below.

Index	Value
0	Minimum x-value
1	Minimum y-value
2	Maximum x-value
3	Maximum y-value

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);
});

queryElevation

Method

Signature: queryElevation (geometry: Point, options?: ElevationQueryOptions): Promise<ElevationQueryResult<Point>>

Parameters

Parameter	Type	Description	Required
geometry	`Point`
options	`ElevationQueryOptions`

Returns: Promise<ElevationQueryResult<Point>>

queryElevation

Method

Signature: queryElevation (geometry: Multipoint, options?: ElevationQueryOptions): Promise<ElevationQueryResult<Multipoint>>

Parameters

Parameter	Type	Description	Required
geometry	`Multipoint`
options	`ElevationQueryOptions`

Returns: Promise<ElevationQueryResult<Multipoint>>

queryElevation

Method

Signature: queryElevation (geometry: Polyline, options?: ElevationQueryOptions): Promise<ElevationQueryResult<Polyline>>

Parameters

Parameter	Type	Description	Required
geometry	`Polyline`
options	`ElevationQueryOptions`

Returns: Promise<ElevationQueryResult<Polyline>>

queryElevation

Method

Signature: queryElevation (geometry: ElevationQueryGeometry, options?: ElevationQueryOptions): Promise<ElevationQueryResult<ElevationQueryGeometry>>

Since: ArcGIS Maps SDK for JavaScript 4.12

Queries the service layer for elevation values for the given geometry.

The returned result contains a copy of the geometry with z-values sampled from elevation data from the service. The resolution from which the elevation is queried can be set using the demResolution option. In many cases, auto demResolution can be used to get high quality elevation samples without the need to know exactly where the data in the service is located. This is particularly useful for services which combine elevation data from many sources (such as the world elevation service). If more control, or higher quality samples are required, use either finest-contiguous or a fixed {number} resolution.

See also

ElevationLayer.queryElevation()

Parameters

Parameter	Type	Description	Required
geometry	`ElevationQueryGeometry`	The geometry to use for sampling elevation data.
options	`ElevationQueryOptions`	Additional query options.

Returns: Promise<ElevationQueryResult<ElevationQueryGeometry>>
Resolves to an object with the sampled geometry, resolution information, and no data value.

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

layerview-create

inherited Event

layerview-create: CustomEvent<LayerLayerviewCreateEvent>

Inherited from: Layer

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

inherited Event

layerview-create-error: CustomEvent<LayerLayerviewCreateErrorEvent>

Inherited from: Layer

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

inherited Event

layerview-destroy: CustomEvent<LayerLayerviewDestroyEvent>

Inherited from: Layer

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

Type definitions

FetchTileOptions

Type definition

Supertypes: AbortOptions

noDataValue

Property

Type: number | undefined

The value representing pixels in the tile that don't contain an elevation value.