Basemap | References | ArcGIS Maps SDK for JavaScript

import Basemap from "@arcgis/core/Basemap.js";

Inheritance:: Basemap→Accessor

Since: ArcGIS Maps SDK for JavaScript 4.0

Overview

A basemap is a collection of layers that provide geographic context to a map or scene with data such as topographic features, road networks, buildings, and labels. These features can be represented with different styles as applicable to your application, such as streets, topographic, or imagery.

A basemap can contain both base layers, which comprise one or more layers, and reference layers. Reference layers are displayed on top of the base layers and all other layers in the map. They can be used to display labels on top of terrain or streets.

Creating a Basemap

Creates a new basemap object. Basemaps can be created in a variety of ways:

From a PortalItem
```
// in this case the portalItem has to be a webmap
const basemap = new Basemap({
  portalItem: {
    id: "8dda0e7b5e2d4fafa80132d59122268c" // WGS84 Streets Vector webmap
  }
});
```

From a basemap id

// create the basemap from a basemap id
Basemap.fromId("topo-vector");

From a basemap style

// create a basemap from the basemap styles service
const basemap = new Basemap({
  style: {
    id: "arcgis/outdoor",
    language: "es" // displays basemap place labels in spanish
  }
});

From a custom basemap layer. These basemaps may be created from services you publish to your own server, or from services published by third parties.

// create from a third party source
const basemap = new Basemap({
  baseLayers: [
    new WebTileLayer(...)
  ],
  referenceLayers: [
    new WebTileLayer(...)
  ]
});

Setting the LOD

The MapView.constraints.lods property should be specified when using a dynamic service for a basemap. Do this by either explicitly setting the lods within this property, or create the lods via the TileInfo.create() method on the TileInfo class. This method is used to create a new TileInfo instance with preset properties for TileInfo.lods. See Zoom and LODs section in MapView SDK document for more information.

// create a basemap from a dynamic MapServer
const basemap = new Basemap({
  baseLayers: [
    new MapImageLayer({
      url: "url to your dynamic MapServer",
      title: "Basemap"
    })
  ],
  title: "basemap",
  id: "basemap"
});

const map = new Map({
  basemap: basemap
});

// create a TileInfo instance using the default settings and
// pass its resulting LOD's to a MapView's constraints
// in this case, lods will match the ArcGIS Online web mercator LODs
const view = new MapView({
  container: "viewDiv",
  map: map,
  constraints: {
    lods: TileInfo.create().lods
  }
});

Waiting for Load

The when() method on the Basemap instance can be called to execute processes that may only run after the Basemap is loaded.

Note: Basemaps containing 3D layers can only be used in a SceneView.

See also

Constructors

Constructor

Parameters

Parameter	Type	Description	Required
properties	`BasemapProperties`

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
`baseLayers`	`Collection<Layer>`
`declaredClass` readonly inherited	`string`	Accessor
`groundLayers`	`Collection<BasemapGroundLayer>`
`id`	`string \| null \| undefined`
`loaded` readonly	`boolean`
`loadError` readonly inherited	`EsriError \| null \| undefined`	LoadableMixin
`loadStatus` readonly inherited	`"not-loaded" \| "loading" \| "failed" \| "loaded"`	LoadableMixin
`loadWarnings` readonly inherited	`any[]`	LoadableMixin
`portalItem`	`PortalItem \| null \| undefined`
`referenceLayers`	`Collection<Layer>`
`spatialReference`	`SpatialReference`
`style`	`BasemapStyle \| null \| undefined`
`thumbnailUrl`	`string \| null \| undefined`
`title`	`string`

baseLayers

autocast Property

Type: Collection<Layer>

A collection of layers that make up the basemap's features.

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.

groundLayers

Property

Type: Collection<BasemapGroundLayer>

A collection of 3D Tiles IM layers (currently at most one supported) If any layer is added here that has global coverage, it will override both ground.layers and basemap.baselayers

id

Property

Type: string | null | undefined

An identifier used to refer to the basemap when referencing it elsewhere.

Example

const customBasemap = new Basemap({
  baseLayers: [layers],
  title: "Custom Basemap",
  id: "myBasemap"
});

loaded

readonly Property

Type: boolean

Indicates whether the basemap instance has 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.

portalItem

autocast Property

Type: PortalItem | null | undefined

The portal item.

referenceLayers

autocast Property

Type: Collection<Layer>

A collection of reference layers which are displayed over the base layers and all other layers in the map. They can be used to display labels on top of terrain or streets.

spatialReference

autocast Property

Type: SpatialReference

Since: ArcGIS Maps SDK for JavaScript 4.14

The spatial reference of the Basemap. For complete listings of supported coordinate systems, see Using spatial references.

When using an Esri basemap, the default spatial reference is Web Mercator Auxiliary Sphere.

style

autocast Property

Type: BasemapStyle | null | undefined

Since: ArcGIS Maps SDK for JavaScript 4.28

The style of the basemap from the basemap styles service (v2). The basemap styles service is a ready-to-use location service that serves vector and image tiles representing geographic features around the world.

You can use the service to display:

Streets and navigation styles
Imagery, oceanic, and topographic styles
Creative styles such as nova and blueprint
Localized place labels
Places with styles - since 4.29
Worldview boundaries - since 4.29

Use of the basemap style service requires authentication via an API key or user authentication. To learn more about API key authentication, see the API key authentication page in the Esri Developer documentation.

Examples

// creates an arcgis streets basemap with french place labels
const basemap = new Basemap({
  style: {
    id: "arcgis/streets",
    language: "fr"
  }
});

// creates an arcgis navigation basemap with places
const basemap = new Basemap({
  style: {
    id: "arcgis/navigation",
    places: "all"
  }
});

thumbnailUrl

Property

Type: string | null | undefined

The URL pointing to an image that represents the basemap. When using a custom basemap in the Basemap Toggle component, the image specified here will display in the component. When the user clicks the image, the map's basemap will update to the basemap associated with the image.

See also

Sample - Custom basemap

title

Property

Type: string

The title of the basemap.

Default value: "Basemap"

Methods

Method	Signature	Class
`fromId` static	`fromId(id: string): Basemap \| null \| undefined`
`fromJSON` inherited static	`fromJSON(json: any): any`	JSONSupportMixin
`cancelLoad` inherited	`cancelLoad(): this`	LoadableMixin
`clone`	`clone(): Basemap`
`destroy`	`destroy(): void`
`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
`loadAll`	`loadAll(): Promise<this>`
`toJSON` inherited	`toJSON(): any`	JSONSupportMixin
`when` inherited	`when<TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> \| null \| undefined, onRejected?: OnRejectedCallback<TResult2> \| null \| undefined): Promise<TResult1 \| TResult2>`	EsriPromiseMixin

fromId

static Method

Signature: fromId (id: string): Basemap | null | undefined

Creates a new basemap instance from a basemap id. See basemap id for a list of possible values.

Parameters

Parameter	Type	Description	Required
id	`string`	The basemap id.

Returns: Basemap | null | undefined
A new Basemap instance.

Examples

const streetsBasemap = Basemap.fromId("streets-vector");

const nightBasemap = Basemap.fromId("streets-night-vector");

fromJSON

inheritedstatic Method

Signature: fromJSON (json: any): any

Inherited from: JSONSupportMixin

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product. The object passed into the input json parameter often comes from a response to a query operation in the REST API or a toJSON() method from another ArcGIS product. See the Using fromJSON() topic in the Guide for details and examples of when and how to use this function.

Parameters

Parameter	Type	Description	Required
json	`any`	A JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects.

Returns: any
Returns a new instance of this class.

cancelLoad

inherited Method

Signature: cancelLoad (): this

Inherited from: LoadableMixin

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

Returns: this

clone

Method

Signature: clone (): Basemap

Creates a deep clone of this object.

Returns: Basemap
A deep clone of the Basemap instance that invoked this method.

destroy

Method

Signature: destroy (): void

Since: ArcGIS Maps SDK for JavaScript 4.17

Destroys the basemap, and any associated resources, including its baseLayers and portalItem. These can no longer be used once the basemap has been destroyed. To prevent these objects from being destroyed, remove them from the basemap before calling destroy().

// prevent the layers from being destroyed by removing them from the basemap
const baseLayers = basemap.baseLayers.removeAll();
const referenceLayers = basemap.referenceLayers.removeAll();

// unset portalItem from the basemap so that it is not destroyed
const portalItem = basemap.portalItem;
basemap.portalItem = null;

// destroy the basemap and any remaining associated resources
basemap.destroy();

See also

Returns: void

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.

loadAll

Method

Signature: loadAll (): Promise<this>

Since: ArcGIS Maps SDK for JavaScript 4.9

Loads all the externally loadable resources associated with the basemap. For the basemap this will load all the base layers and reference layers.

See also

load()

Returns: Promise<this>
Resolves when all the loadable resources have been loaded. Rejects if at least one of the loadable resources failed to load.

Example

// Load all resources but ignore if one or more of them failed to load
basemap.loadAll()
  .catch(function(error) {
    // Ignore any failed resources
  })
  .then(function() {
    console.log("All loaded");
  });

toJSON

inherited Method

Signature: toJSON (): any

Inherited from: JSONSupportMixin

Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.

Returns: any
The ArcGIS portal JSON representation of an instance of this class.

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
});