ElevationLayer

let elevLyr = new ElevationLayer({
  // Custom elevation service
  url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Elevation/MtBaldy_Elevation/ImageServer"
});
// Add elevation layer to the map's ground.
map.ground.layers.add(elevLyr);

Property Overview

Property Details

copyright String

The copyright text as defined by the service.

declaredClass Stringreadonly inherited

Since: ArcGIS Maps SDK for JavaScript 4.7

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

fullExtent Extentautocast inherited

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 String inherited

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

listMode String inherited

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"

loaded Booleanreadonly inherited

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

Default Value:false

loadError Errorreadonly inherited

The Error object returned if an error occurred while loading.

Default Value:null

loadStatus Stringreadonly inherited

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 Object[]readonly inherited

A list of warnings which occurred while loading.

opacity Number inherited

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;

portalItem PortalItem

The portal item from which the layer is loaded. If the portal item references a Feature Service or Scene Service, then you can specify a single layer to load with the layerId property.

Beginning with 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.

Examples

// While this example uses FeatureLayer, this same pattern can be
// used for other layers that may be loaded from portalItem ids.
const layer = new FeatureLayer({
  portalItem: {  // autocasts as new PortalItem()
    id: "caa9bd9da1f4487cb4989824053bb847"
  }  // the first layer in the service is returned
});

// Set hostname when using an on-premise portal (default is ArcGIS Online)
// esriConfig.portalUrl = "http://myHostName.esri.com/arcgis";

// While this example uses FeatureLayer, this same pattern can be
// used for SceneLayers.
const layer = new FeatureLayer({
  portalItem: {  // autocasts as new PortalItem()
    id: "8d26f04f31f642b6828b7023b84c2188"
  },
  // loads the third item in the given feature service
  layerId: 2
});

// Initialize GeoJSONLayer by referencing a portalItem id pointing to geojson file.
const layer = new GeoJSONLayer({
  portalItem: new PortalItem({
    id: "81e769cd7031482797e1b0768f23c7e1",
    // optionally define the portal, of the item.
    // if not specified, the default portal defined is used.
    // see https://developers.arcgis.com/javascript/latest/api-reference/esri-config.html#portalUrl
    portal: new Portal({
      url: "https://jsapi.maps.arcgis.com/"
    })
  }
});

// This snippet loads a table hosted in ArcGIS Online.
const table = new FeatureLayer({
  portalItem: { // autocasts as esri/portal/PortalItem
    id: "123f4410054b43d7a0bacc1533ceb8dc"
  }
});

// Before adding the table to the map, it must first be loaded and confirm it is the right type.
table.load().then(function() {
  if (table.isTable) {
    map.tables.add(table);
  }
});

sourceJSON Object

Since: ArcGIS Maps SDK for JavaScript 4.13

The image service's metadata JSON exposed by the ArcGIS REST API. While most commonly used properties are exposed on the ElevationLayer class directly, this property gives access to all information returned by the elevation image service. This property is useful if working in an application built using an older version of the API which requires access to elevation image service properties from a more recent version.

spatialReference SpatialReferencereadonly

The spatial reference of the layer as defined by the service.

tileInfo TileInfo

Contains information about the tiling scheme for the layer.

title String

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

When loading a layer by service url, the title is derived from the service name. When the layer is loaded from a portal item, the title of the portal item will be used instead. Finally, 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 Stringreadonly

For ElevationLayer the type is always "elevation".

url String

URL pointing to the Elevation layer resource on an ArcGIS Image Server.

Example

url: "http://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"

visible Boolean inherited

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;

Method Overview

Method Details

addHandles(handleOrHandles, groupKey)inherited

Since: ArcGIS Maps SDK for JavaScript 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()inherited

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

createElevationSampler(extent, options){Promise<ElevationSampler>}

Since: ArcGIS Maps SDK for JavaScript 4.7

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

Specification

extent Extent The extent for which to create the sampler.

options Object optional Additional query options. See the table below. Specification demResolution Number|String optional Default Value: auto Controls the horizontal resolution (cell size) in meters from which elevation data is sampled (defaults to auto). See ElevationLayer for more details. noDataValue Number optional Default Value: 0 The value to use when there is no data available. signal AbortSignal optional An AbortSignal to abort the request. If canceled, the promise will be rejected with an error named AbortError. See also AbortController.

Returns

Type	Description
Promise<ElevationSampler>	An elevation sampler.

createLayerView(view, options){Promise<LayerView>}inherited

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()inherited

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

• Map.destroy()
• WebMap.destroy()
• WebScene.destroy()
• Basemap.destroy()
• Ground.destroy()
• PortalItem.destroy()

emit(type, event){Boolean}inherited

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

type String The name of the event.

event Object optional The event payload.

Returns

Type	Description
Boolean	true if a listener was notified

fetchAttributionData(){Promise<object>}inherited

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.

fetchTile(level, row, column, options){Promise<ElevationTileData>}

Requests a tile from the service and decodes the data into a linear array of elevation values.

The returned promise resolves with a plain object describing the obtained elevation data for the tile. The object has the following properties:

Property	Type	Description
values	Float32Array	The elevation values contained in the tile.
width	number	The number of elevation values in one row of the tile.
height	number	The number of elevation values in one column of the tile.
maxZError	number	The upper bound for the compression error on the elevation values.

Parameters

Specification

level Number the tile level.

row Number the tile row.

column Number the tile column.

options Object optional Optional settings for the tile request. Specification noDataValue Number optional The value representing pixels in the tile that don't contain an elevation value. signal AbortSignal optional An AbortSignal to abort the request. If canceled, the promise will be rejected with an error named AbortError. See also AbortController.

Returns

Type	Description
Promise<ElevationTileData>	a Promise which resolves with elevation tile data.

getTileUrl(level, row, col){String}

This method returns a URL to a tile for a given level, row and column.

Parameters

level Number The requested tile's level.

row Number The requested tile's row.

col Number The requested tile's column.

Returns

Type	Description
String	Returns the tile URL.

hasEventListener(type){Boolean}inherited

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(groupKey){Boolean}inherited

Since: ArcGIS Maps SDK for JavaScript 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(){Boolean}inherited

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(){Boolean}inherited

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(){Boolean}inherited

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(signal){Promise}inherited

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(type, listener){Object}inherited

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);
});

queryElevation(geometry, options){Promise<ElevationQueryResult>}

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.

Parameters

Specification

geometry Point|Multipoint|Polyline The geometry to use for sampling elevation data.

options Object optional Additional query options. See the table below. Specification demResolution Number|String optional Default Value: auto Controls the horizontal resolution (cell size) in meters from which elevation data is sampled (defaults to auto). See the table below for more details on the different settings. demResolution Description auto Automatically chooses an appropriate resolution for each coordinate of the input geometry. The current implementation will try to use the finest available resolution given that the total required number of tile requests does not exceed a certain maximum amount (currently 20). Note that this may result in values being sampled from different resolutions. finest-contiguous Sample elevation from the finest available resolution (cell size) across the entire geometry. {number} Sample elevation from the resolution closest to the specified resolution (in meters). returnSampleInfo Boolean optional Default Value: false Indicates whether to return additional sample information for each coordinate. noDataValue Number optional Default Value: 0 The value to use when there is no data available. signal AbortSignal optional An AbortSignal to abort the request. If canceled, the promise will be rejected with an error named AbortError. See also AbortController.

Returns

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

Example

require(["esri/layers/ElevationLayer", "esri/geometry/Multipoint"], function (
 ElevationLayer,
 Multipoint
) {
 const url =
   "//elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer/";
 const layer = new ElevationLayer(url);

 // Various points across a ridge of the mount everest
 const points = [
   [86.9252, 27.9883],
   [86.9265, 27.9894],
   [86.9292, 27.9923],
   [86.9324, 27.996],
   [86.9359, 27.9992]
 ];

 // Uses "auto" resolution by default
 layer
   .queryElevation(new Multipoint({ points }), {
     returnSampleInfo: true
   })

   // Successfully sampled all points
   .then(function (result) {
     // Print result of each sampled point to the console
     result.geometry.points.forEach(function (point, index) {
       const elevation = Math.round(point[2]);
       const resolution = result.sampleInfo[index].demResolution;

       const coordinateText = "(" + point[0] + ", " + point[1] + ")";
       const resolutionText = Math.round(resolution) + " meter resolution";

       console.log("Sampled " + coordinateText + ": " + elevation + " at " + resolutionText);
     });
   })

   // Failed to sample (e.g. service unavailable)
   .catch(function (error) {
     console.error("Failed to query elevation:", error);
   });
});

removeHandles(groupKey)inherited

Since: ArcGIS Maps SDK for JavaScript 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(callback, errback){Promise}inherited

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: 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
});

Type Definitions

ElevationQueryResult

Object returned when queryElevation() promise resolves:

Properties

geometry Point|Multipoint|Polyline The geometry with sampled z-values.

sampleInfo Object[] optional Contains additional information about how the geometry was sampled. This property is present depending on whether the user set options.returnSampleInfo = true, for each coordinate in the geometry. Specification demResolution Number The resolution at which the z-value was sampled. If no data was available for sampling for a given coordinate, the dem resolution value will be -1 for that coordinate.

noDataValue Number The value used when there is no data available.

Event Overview

Event Details

layerview-createinherited

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-errorinherited

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-destroyinherited

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.