MapImageLayer | References | ArcGIS Maps SDK for JavaScript

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

Inheritance:: MapImageLayer→Layer→Accessor

Since: ArcGIS Maps SDK for JavaScript 4.0

Overview

MapImageLayer allows you to display and analyze data from sublayers defined in a map service, exporting images instead of features. Map service images are dynamically generated on the server based on a request, which includes an LOD (level of detail), a bounding box, dpi, spatial reference and other options. In 2D, the exported image is of the entire map extent specified. In 3D, two images are exported: an image with higher resolution for the area closer to the camera and a lower resolution image for the area farther away from the camera.

Unlike FeatureLayer, MapImageLayer processing is handled by the server, not the client. Offloading the processing to the server allows MapImageLayer to render more features with a higher level of performance in some cases.

MapImageLayer does not display tiled images. To display tiled map service layers, see TileLayer.

Creating a MapImageLayer

MapImageLayer may be created in one of two ways: from a service URL or from an ArcGIS Portal item ID.

Reference a service URL

To create a MapImageLayer instance from a service, you must set the url property to the REST endpoint of a layer in a Map Service. The URL will typically look like the following.

https://<hostname>/arcgis/rest/services/<service-name>/MapServer

For a layer to be visible in a view, it must be added to the Map referenced by the view. See Map.add() for information about adding layers to a map.

const MapImageLayer = await $arcgis.import("@arcgis/core/layers/MapImageLayer.js");
// points to the states layer in a service storing U.S. census data
let layer = new MapImageLayer({
  url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer"
});
map.add(layer);  // adds the layer to the map

If the map service is requested from a different domain, a CORS enabled server or a proxy is required.

Reference an ArcGIS portal Item ID

You can also create a MapImageLayer from its ID if it exists as an item in ArcGIS Online or ArcGIS Enterprise. For example, the following snippet shows how to add a new MapImageLayer instance to a map using the portalItem property.

// references an ArcGIS Online item pointing to a Map Service Layer
let layer = new MapImageLayer({
  portalItem: {  // autocasts as esri/portal/PortalItem
    id: "8444e275037549c1acab02d2626daaee"
  }
});
map.add(layer);  // adds the layer to the map

Sublayers

Map services contain one or more sublayers. Sublayers may even contain nested sublayers. When the sublayers property of the MapImageLayer is not specified, then an image of all sublayers in the service is exported to the client. If a subset of sublayers from the service are specified, then only the subset of sublayers are rendered on the client. Sublayers have default rendering, scale visibility, labels, and other properties saved to the server. However, these properties may be dynamically changed so a new map image is exported to the view. Sublayers of a MapImageLayer can only be styled with 2D symbology even if they are rendered in a WebScene. To learn more about working with sublayers, see the Sublayer API documentation.

Dynamic layers

Sublayers may be rendered on the fly as dynamic layers. There are two types of dynamic layers: DynamicMapLayer and DynamicDataLayer.

Dynamic map layers allow you to override sublayers in the map service with new renderers, definition expressions, opacity, scale visibility, etc. Multiple dynamic map layers may exist for a single map service layer.

Dynamic data layers provide the ability to create layers on the fly from data referenced in registered workspaces. The data may be tables with or without geometries, feature classes, and rasters. These data sources are not directly visible to the services directory, but may be published and configured with the ArcGIS Server Manager. Data from tables may be joined to other tables or dynamic map layers.

Esri requires that when you use an ArcGIS Online basemap in your app, the map must include Esri attribution and you must be licensed to use the content. For detailed guidelines on working with attribution, please visit the official attribution in your app documentation. For information, see the Terms of Use documentation.

See also

Example

let layer = new MapImageLayer({
url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer",
  sublayers: [
   {
     id: 3,
     visible: false
   }, {
     id: 2,
     visible: true
   }, {
     id: 1,
     visible: true
   }, {
     id: 0,
     visible: true,
     definitionExpression: "pop2000 > 100000"
   }
 ]
});

Constructors

Constructor

Parameters

Parameter	Type	Description	Required
properties	`MapImageLayerProperties`

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

Example

// Typical usage
let layer = new MapImageLayer({
  // URL to the map service
  url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer",
  // dynamic sublayers. See sublayers documentation for more info
  sublayers: [ {}, {}, {} ]
});

Properties

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

Property	Type	Class
`allSublayers` readonly	`Collection<Sublayer>`
`apiKey` inherited	`string \| null \| undefined`	APIKeyMixin
`blendMode` inherited	`BlendMode`	BlendLayer
`capabilities` readonly inherited	`MapServiceCapabilities`	ArcGISMapService
`copyright` inherited	`string \| null \| undefined`	ArcGISMapService
`customParameters` inherited	`CustomParameters \| null \| undefined`	CustomParametersMixin
`dateFieldsTimeZone` readonly	`TimeZone \| null \| undefined`
`datesInUnknownTimezone` readonly	`boolean`
`declaredClass` readonly inherited	`string`	Accessor
`dpi`	`number`
`effect` inherited	`Effect \| null \| undefined`	BlendLayer
`fullExtent` inherited	`Extent \| null \| undefined`	ArcGISMapService
`gdbVersion`	`string \| null \| undefined`
`id` inherited	`string`	Layer
`imageFormat`	`MapImageLayerImageFormat`
`imageMaxHeight`	`number`
`imageMaxWidth`	`number`
`imageTransparency`	`boolean`
`legendEnabled` inherited	`boolean`	ArcGISMapService
`listMode` inherited	`LayerListMode`	Layer
`loaded` readonly	`boolean`
`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` inherited	`boolean`	OperationalLayer
`portalItem`	`PortalItem \| null \| undefined`
`preferredTimeZone` readonly	`TimeZone \| null \| undefined`
`refreshInterval` inherited	`number`	RefreshableLayer
`sourceJSON`	`any \| null \| undefined`
`spatialReference` readonly inherited	`SpatialReference`	ArcGISMapService
`sublayers`	`Collection<Sublayer> \| null \| undefined`
`subtables` inherited	`Collection<Sublayer> \| null \| undefined`	SublayersOwner
`timeExtent` inherited	`TimeExtent \| null \| undefined`	TemporalLayer
`timeInfo` inherited	`TimeInfo \| null \| undefined`	TemporalLayer
`timeOffset` inherited	`TimeInterval \| null \| undefined`	TemporalLayer
`title`	`string \| null \| undefined`
`type` readonly	`"map-image"`
`uid` readonly inherited	`string`	IdentifiableMixin
`url`	`string \| null \| undefined`
`useViewTime` inherited	`boolean`	TemporalLayer
`version` readonly inherited	`number`	ArcGISMapService
`visibilityTimeExtent` inherited	`TimeExtent \| null \| undefined`	Layer
`visible` inherited	`boolean`	Layer

allSublayers

readonly Property

Type: Collection<Sublayer>

A flat Collection of all the sublayers in the MapImageLayer including the sublayers of its sublayers. All sublayers are referenced in the order in which they are drawn in the view (bottom to top).

Example

// finds the census tracts sublayer from a parent sublayer of the
// MapImageLayer containing various census sublayers
let tractsId = 5;
let tracksSublayer = layer.allSublayers.find(function(sublayer){
  return sublayer.id === tracksId;
});

apiKey

inherited Property

Type: string | null | undefined

Inherited from: APIKeyMixin

Since: ArcGIS Maps SDK for JavaScript 4.20

An authorization string used to access a resource or service. This property will append the API key to all requests made by the layer to the service. API keys are generated and managed in the portal. An API key is tied explicitly to an ArcGIS account; it is also used to monitor service usage. Setting a fine-grained API key on a specific class overrides the global API key.

If loading a secure layer with API authentication via a PortalItem, the API key needs to be set on the layer's portalItem property.

See also

Example

// set the api key to access a protected service
const layer = new FeatureLayer({
  url: serviceUrl,
  apiKey: "YOUR_API_KEY"
});

blendMode

inherited Property

Type: BlendMode

Inherited from: BlendLayer

Since: ArcGIS Maps SDK for JavaScript 4.16

Blend modes are used to blend layers together to create an interesting effect in a layer, or even to produce what seems like a new layer. Unlike the method of using transparency which can result in a washed-out top layer, blend modes can create a variety of very vibrant and intriguing results by blending a layer with the layer(s) below it.

When blending layers, a top layer is a layer that has a blend mode applied. All layers underneath the top layer are background layers. The default blending mode is normal where the top layer is simply displayed over the background layer. While this default behavior is perfectly acceptable, the use of blend modes on layers open up a world of endless possibilities to generate creative maps.

The layers in a GroupLayer are blended together in isolation from the rest of the map.

In the following screenshots, the vintage shaded relief layer is displayed over a firefly world imagery layer. The color blend mode is applied to the vintage shaded relief and the result looks like a new layer.

Known Limitations

In 3D SceneViews, the blendMode is supported on BaseTileLayer, ImageryTileLayer, OpenStreetMapLayer, TileLayer, VectorTileLayer, WCSLayer, WebTileLayer, WMTSLayer and GroupLayer.
When working with GroupLayers in a 3D SceneView, the blendMode is only applied to the sublayers that support it.
The blendMode is not supported in the Legend.
See print for known printing limitations.

The following factors will affect the blend result:

Order of all layers
Layer opacity
Opacity of features in layers
Visibility of layers
By default, the very bottom layer in a map is drawn on a transparent background. You can change the MapView's background color.

Blend mode	Description
normal	The top layer is displayed over the background layer. The data of the top layer block the data of background layer where they overlap.
average	Takes the mathematical average of top and background layers. Result of `average` blend mode is often similar to the effect of setting the layer's opacity to 50%.

Lighten blend modes:

The following blend modes create lighter results than all layers. In lighten blend modes, pure black colors in the top layer become transparent allowing the background layer to show through. White in the top layer will stay unchanged. Any color that is lighter than pure black is going to lighten colors in the top layer to varying degrees all way to pure white.

Lighten blend modes can be useful when lightening dark colors of the top layer or removing black colors from the result. The plus, lighten and screen modes can be used to brighten layers that have faded or dark colors on a dark background.

Blend mode	Description
lighten	Compares top and background layers and retains the lighter color. Colors in the top layer become transparent if they are darker than the overlapping colors in the background layer allowing the background layer to show through completely. Can be thought of as the opposite of `darken` blend mode.
lighter	Colors in top and background layers are multiplied by their alphas (layer opacity and layer's data opacity. Then the resulting colors are added together. All overlapping midrange colors are lightened in the top layer. The opacity of layer and layer's data will affect the blend result.
plus	Colors in top and background layers are added together. All overlapping midrange colors are lightened in the top layer. This mode is also known as `add` or `linear-dodge`.
screen	Multiplies inverted colors in top and background layers then inverts the colors again. The resulting colors will be lighter than the original color with less contrast. Screen can produce many different levels of brightening depending on the luminosity values of the top layer. Can be thought of as the opposite of the `multiply` mode.
color-dodge	Divides colors in background layer by the inverted top layer. This lightens the background layer depending on the value of the top layer. The brighter the top layer, the more its color affects the background layer. Decreases the contrast between top and background layers resulting in saturated mid-tones and blown highlights.

Darken blend modes:

The following blend modes create darker results than all layers. In darken blend modes, pure white in the top layer will become transparent allowing the background layer to show through. Black in the top layer will stay unchanged. Any color that is darker than pure white is going to darken a top layer to varying degrees all the way to pure black.

The multiply blend mode is often used to highlight shadows, show contrast, or accentuate an aspect of a map. For example, you can use multiply blend mode on a topographic map displayed over hillshade when you want to have your elevation show through the topographic layer. See the intro to layer blending sample.

The multiply and darken modes can be used to have dark labels of the basemap to show through top layers. See the darken blending sample.

The color-burn mode works well with colorful top and background layers since it increases saturation in mid-tones. It increases the contrast by tinting pixels in overlapping areas in top and bottom layers more towards the top layer color. Use this blend mode, when you want an effect with more contrast than multiply or darken.

The following screenshots show how the multiply blend mode used for creating a physical map of the world that shows both boundaries and elevation. multiply-blend

Blend mode	Description
darken	Emphasizes the darkest parts of overlapping layers. Colors in the top layer become transparent if they are lighter than the overlapping colors in the background layer, allowing the background layer to show through completely.
multiply	Emphasizes the darkest parts of overlapping layers by multiplying colors of the top layer and the background layer. Midrange colors from top and background layers are mixed together more evenly.
color-burn	Intensifies the dark areas in all layers. It increases the contrast between top and background layers, by tinting colors in overlapping area towards the top color. To do this it inverts colors of the background layer, divides the result by colors of the top layer, then inverts the results.

Contrast blend modes:

The following blend modes create contrast by both lightening the lighter areas and darkening the darker areas in the top layer by using lightening or darkening blend modes to create the blend. The contrast blend modes will lighten the colors lighter than 50% gray ([128,128,128]), and darken the colors darker than 50% gray. 50% gray will be transparent in the top layer. Each mode can create a variety of results depending on the colors of top and background layers being blended together. The overlay blend mode makes its calculations based on the brightness of the colors in the background layer while all of the other contrast blend modes make their calculations based on the brightness of the top layer. Some of these modes are designed to simulate the effect of shining a light through the top layer, effectively projecting upon the layers beneath it.

Contrast blend modes can be used to increase the contrast and saturation to have more vibrant colors and give a punch to your layers. For example, you can duplicate a layer and set overlay blend mode on the top layer to increase the contrast and tones of your layer. You can also add a polygon layer with a white fill symbol over a dark imagery layer and apply soft-light blend mode to increase the brightness in the imagery layer.

The following screenshots show an effect of the overlay blend mode on a GraphicsLayer. The left image shows when the buffer graphics layer has the normal blend mode. As you can see, the gray color for the buffer polygon is blocking the intersecting census tracts. The right image shows when the overlay blend mode is applied to the buffer graphics layer. The overlay blend mode darkens or lightens the gray buffer polygon depending on the colors of the background layer while the census tracts layer is shining through. See this in action.

Normal blend mode	Overlay blend mode

Blend mode	Description
overlay	Uses a combination of `multiply` and `screen` modes to darken and lighten colors in the top layer with the background layer always shining through. The result is darker color values in the background layer intensify the top layer, while lighter colors in the background layer wash out overlapping areas in the top layer.
soft-light	Applies a half strength `screen` mode to lighter areas and half strength `multiply` mode to darken areas of the top layer. You can think of the `soft-light` as a softer version of the `overlay` mode.
hard-light	Multiplies or screens the colors, depending on colors of the top layer. The effect is similar to shining a harsh spotlight on the top layer.
vivid-light	Uses a combination of `color-burn` or `color-dodge` by increasing or decreasing the contrast, depending on colors in the top layer.

Component blend modes:

The following blend modes use primary color components, which are hue, saturation and luminosity to blend top and background layers. You can add a feature layer with a simple renderer over any layer and set hue, saturation, color or luminosity blend mode on this layer. With this technique, you create a brand new looking map.

The following screenshots show where the topo layer is blended with world hillshade layer with luminosity blend mode. The result is a drastically different looking map which preserves the brightness of the topo layer while adapting the hue and saturation of the hillshade layer.

Blend mode	Description
hue	Creates an effect with the hue of the top layer and the luminosity and saturation of the background layer.
saturation	Creates an effect with the saturation of the top layer and the hue and luminosity of the background layer. 50% gray with no saturation in the background layer will not produce any change.
luminosity	Creates effect with the luminosity of the top layer and the hue and saturation of the background layer. Can be thought of as the opposite of `color` blend mode.
color	Creates an effect with the hue and saturation of the top layer and the luminosity of the background layer. Can be thought of as the opposite of `luminosity` blend mode.

Composite blend modes:

The following blend modes can be used to mask the contents of top, background or both layers.

Destination modes are used to mask the data of the top layer with the data of the background layer.
Source modes are used to mask the data of the background layer with the data of the top layer.

The destination-in blend mode can be used to show areas of focus such as earthquakes, animal migration, or point-source pollution by revealing the underlying map, providing a bird's eye view of the phenomenon. Check out multiple blending and groupLayer blending samples to see composite blend modes in action.

The following screenshots show feature and imagery layers on the left side on their own in the order they are drawn in the view. The imagery layer that contains land cover classification rasters. The feature layer contains 2007 county crops data. The right image shows the result of layer blending where destination-in blendMode is set on the imagery layer. As you can see, the effect is very different from the original layers. The blended result shows areas of cultivated crops only (where both imagery and feature layers overlap).

Blend mode	Description
destination-over	Destination/background layer covers the top layer. The top layer is drawn underneath the destination layer. You'll see the top layer peek through wherever the background layer is transparent or has no data.
destination-atop	Destination/background layer is drawn only where it overlaps the top layer. The top layer is drawn underneath the background layer. You'll see the top layer peek through wherever the background layer is transparent or has no data.
destination-in	Destination/background layer is drawn only where it overlaps with the top layer. Everything else is made transparent.
destination-out	Destination/background layer is drawn where it doesn't overlap the top layer. Everything else is made transparent.
source-atop	Source/top layer is drawn only where it overlaps the background layer. You will see the background layer peek through where the source layer is transparent or has no data.
source-in	Source/top layer is drawn only where it overlaps with the background layer. Everything else is made transparent.
source-out	Source/top layer is drawn where it doesn't overlap the background layer. Everything else is made transparent.
xor	Top and background layers are made transparent where they overlap. Both layers are drawn normal everywhere else.

Invert blend modes:

The following blend modes either invert or cancel out colors depending on colors of the background layer. These blend modes look for variations between top and background layers. For example, you can use difference or exclusion blend modes on two imagery layers of forest covers to visualize how forest covers changed from one year to another.

The invert blend mode can be used to turn any light basemap into a dark basemap to accommodate those who work in low-light conditions. The following screenshots show how setting the invert blend mode set on a feature layer with a simple renderer turns the world Hillshade into a dark themed basemap in no time.

Blend mode	Description
difference	Subtracts the darker of the overlapping colors from the lighter color. When two pixels with the same value are subtracted, the result is black. Blending with black produces no change. Blending with white inverts the colors. This blending mode is useful for aligning layers with similar content.
exclusion	Similar to the `difference` blend mode, except that the resulting image is lighter overall. Overlapping areas with lighter color values are lightened, while darker overlapping color values become transparent.
minus	Subtracts colors of the top layer from colors of the background layer making the blend result darker. In the case of negative values, black is displayed.
invert	Inverts the background colors wherever the top and background layers overlap. The invert blend mode inverts the layer similar to a photographic negative.
reflect	This blend mode creates effects as if you added shiny objects or areas of light in the layer. Black pixels in the background layer are ignored as if they were transparent.

See also

Layer blending samples

Default value: "normal"

capabilities

readonlyinherited Property

Type: MapServiceCapabilities

Inherited from: ArcGISMapService

Since: ArcGIS Maps SDK for JavaScript 4.8

Indicates the layer's supported capabilities.

copyright

inherited Property

Type: string | null | undefined

Inherited from: ArcGISMapService

The copyright text as defined by the service.

customParameters

inherited Property

Type: CustomParameters | null | undefined

Inherited from: CustomParametersMixin

Since: ArcGIS Maps SDK for JavaScript 4.18

A list of custom parameters appended to the URL of all resources fetched by the layer. It's an object with key-value pairs where value is a string. The layer's refresh() method needs to be called if the customParameters are updated at runtime.

Example

// send a custom parameter to your special service
let layer = new MapImageLayer({
  url: serviceUrl,
  customParameters: {
    "key": "my-special-key"
  }
});

dateFieldsTimeZone

readonly Property

Type: TimeZone | null | undefined

Since: ArcGIS Maps SDK for JavaScript 4.28

The time zone that dates are stored in. This property does not apply to date fields referenced by timeInfo.

Even though dates are transmitted as UTC epoch values, this property may be useful when constructing date or time where clauses for querying. If constructing date or time where clauses, use FieldsIndex.getTimeZone() to get the time zone for the given date field.

See also

datesInUnknownTimezone

readonly Property

Type: boolean

Since: ArcGIS Maps SDK for JavaScript 4.21

This property is set by the service publisher and indicates that dates should be considered without the local timezone. This applies to both requests and responses.

Known Limitations

This capability is only available with services published with ArcGIS Enterprise 10.9 or greater. When setting timeExtent in a Query, FeatureLayerView.filter or layer, dates must be defined in terms of UTC as illustrated in the code below. When using layer.timeInfo.fullTimeExtent in conjunction with TimeSlider, the local timezone offset must be removed. See the code snippet below.

See also

Default value: false

Examples

// Only download data for the year 2020.
// if the layer supports unknown time zone then create
// the dates in UTC
if (layer.datesInUnknownTimezone) {
  layer.timeExtent = new TimeExtent({
    start: new Date(Date.UTC(2020, 0, 1)),
    end: new Date(Date.UTC(2021, 0, 1))
  });
}
else {
  layer.timeExtent = new TimeExtent({
    start: new Date(2020, 0, 1),
    end: new Date(2021, 0, 1)
  });
}

// set up the timeslider for a service with an unknown timezone
if (layer.datesInUnknownTimezone) {
  const timeSlider = new TimeSlider({
    view: view,
    container: "timeSliderDiv",
    timeVisible: true,
  });
  view.ui.add(timeSlider, "bottom-left");

  view.whenLayerView(layer).then((layerView) => {
   // get the layer's fullTimeExtent and remove the local
   // time zone offset
    const timExtent = new TimeExtent({
      start: removeLocalOffset(layer.timeInfo.fullTimeExtent.start),
      end: removeLocalOffset(layer.timeInfo.fullTimeExtent.end)
    });

    timeSlider.fullTimeExtent = timExtent;
    timeSlider.stops = {
      interval: layer.timeInfo.interval;
    };
  });
}

// Remove the local time zone offset from dates
function removeLocalOffset(localTime) {
  return new Date(
    localTime.getUTCFullYear(),
    localTime.getUTCMonth(),
    localTime.getUTCDate(),
    localTime.getUTCHours(),
    localTime.getUTCMinutes(),
    localTime.getUTCSeconds(),
    localTime.getUTCMilliseconds()
  );
}

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.

dpi

Property

Type: number

The output dots per inch (DPI) of the MapImageLayer.

Default value: 96

effect

inherited Property

Type: Effect | null | undefined

Inherited from: BlendLayer

Since: ArcGIS Maps SDK for JavaScript 4.18

Effect provides various filter functions that can be performed on the layer to achieve different visual effects similar to how image filters work. This powerful capability allows you to apply css filter-like functions to layers to create custom visual effects to enhance the cartographic quality of your maps. This is done by applying the desired effect to the layer's effect property as a string or an array of objects to set scale dependent effects.

Notes

Set featureEffect property on a layer if different effects need to be applied features that meet or fail a specified filter. If all of the following four properties are applied, then they will be applied in this order: featureEffect, effect, opacity and blendMode.

Known Limitations

The effect is not supported in 3D SceneViews.
The effect cannot be applied to a layer with a heatmap renderer.
The effect is not supported in layers with FeatureLayer.featureReduction of type cluster enabled.
See print for known printing limitations.

See also

Examples

// the following effect will be applied to the layer at all scales
// brightness will be applied first, then hue-rotate followed by contrast
// changing order of the effects will change the final result
layer.effect = "brightness(5) hue-rotate(270deg) contrast(200%)";

// set a scale dependent bloom effect on the layer
layer.effect = [
  {
    scale: 36978595,
    value: "drop-shadow(3px, 3px, 4px)"
  },
  {
    scale: 18489297,
    value: "drop-shadow(2px, 2px, 3px)"
  },
  {
    scale: 4622324,
    value: "drop-shadow(1px, 1px, 2px)"
  }
];

fullExtent

autocast inherited Property

Type: Extent | null | undefined

Inherited from: ArcGISMapService

The full extent of the layer as defined by the map service.

Example

// zooms the view to the full extent of the layer
layer.when(function(){
  view.goTo(layer.fullExtent);
});

gdbVersion

Property

Type: string | null | undefined

The version of the geodatabase of the map service data. Read the Overview of versioning topic for more details about this capability.

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.

imageFormat

Property

Type: MapImageLayerImageFormat

The output image type.

Default value: "png24"

imageMaxHeight

Property

Type: number

Since: ArcGIS Maps SDK for JavaScript 4.3

Indicates the maximum height of the image exported by the service.

Default value: 2048

imageMaxWidth

Property

Type: number

Since: ArcGIS Maps SDK for JavaScript 4.3

Indicates the maximum width of the image exported by the service.

Default value: 2048

imageTransparency

Property

Type: boolean

Indicates whether the background of the image exported by the service is transparent.

Default value: true

legendEnabled

inherited Property

Type: boolean

Inherited from: ArcGISMapService

Indicates whether the layer will be included in the legend.

Default value: true

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

readonly Property

Type: boolean

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

Default value: false

loadError

readonlyinherited Property

Type: EsriError | null | undefined

Inherited from: LoadableMixin

The Error object returned if an error occurred while loading.

loadStatus

readonlyinherited Property

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

Inherited from: LoadableMixin

Represents the status of a load() operation.

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

Default value: "not-loaded"

loadWarnings

readonlyinherited Property

Type: any[]

Inherited from: LoadableMixin

A list of warnings which occurred while loading.

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

inherited Property

Type: boolean

Inherited from: OperationalLayer

Since: ArcGIS Maps SDK for JavaScript 4.28

Enable persistence of the layer in a WebMap or WebScene.

Default value: true

portalItem

autocast Property

Type: PortalItem | null | undefined

The portal item from which the layer is loaded. This will load the layer along with any overridden properties (e.g. renderers, definition expressions, etc.) saved to the portal item, not the map service.

Examples

let layer = new MapImageLayer({
  portalItem: {  // autocasts as new PortalItem()
    id: "caa9bd9da1f4487cb4989824053bb847"
  }
});

// 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/references/core/config/#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(() => {
  if (table.isTable) {
    map.tables.add(table);
  }
});

// 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 esri/portal/PortalItem
    id: "caa9bd9da1f4487cb4989824053bb847",
    // Set an API key to access a secure portal item configured with API key authentication.
    apiKey: "APIKEY"
  }
});

preferredTimeZone

readonly Property

Type: TimeZone | null | undefined

Since: ArcGIS Maps SDK for JavaScript 4.28

The IANA time zone the author of the service intended data from date fields to be viewed in.

See also

Wikipedia - List of tz database time zones

refreshInterval

inherited Property

Type: number

Inherited from: RefreshableLayer

Since: ArcGIS Maps SDK for JavaScript 4.6

Refresh interval of the layer in minutes. Value of 0 indicates no refresh.

See also

Default value: 0

Example

// the layer will be refreshed every minute.
layer.refreshInterval = 1;

sourceJSON

Property

Type: any | null | undefined

Since: ArcGIS Maps SDK for JavaScript 4.13

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

spatialReference

readonlyinherited Property

Type: SpatialReference

Inherited from: ArcGISMapService

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

sublayers

autocast Property

Type: Collection<Sublayer> | null | undefined

A Collection of Sublayer objects that allow you to alter the properties of one or more sublayers of the MapImageLayer. If this property is not specified, all the sublayers from the service are displayed as defined in the service. If an empty array is passed to this property then none of the sublayers from the service are displayed in the layer.

All sublayers are referenced in the order in which they are drawn in the view (bottom to top). They may be added, removed, or reordered using the Collection methods. Because Sublayer extends Accessor, its properties may be watched.

Examples

// Only includes the first sublayer from the map service
let layer = new MapImageLayer({
  url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer",
  sublayers: [{
    id: 0
  }]
});

// toggles the visibility of the first sublayer to false
layer.findSublayerById(0).visible = false;

// sublayers from the service are excluded from the layer
layer = new MapImageLayer({
  url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer",
  sublayers: []
});

// Moves the cities sublayer from index 3 to index 0.
let citiesLayer = layer.sublayers.at(3);
layer.sublayers.reorder(citiesLayer, 0);

// Overrides the drawing info on the layer with a custom renderer
let citiesLayer = layer.sublayers.at(3);
citiesLayer.renderer = {
  type: "simple",  // autocasts as new SimpleRenderer()
  symbol: {
    type: "simple-marker",  // autocasts as new SimpleMarkerSymbol()
    color: "blue",
    size: 3
  }
};

subtables

autocast inherited Property

Type: Collection<Sublayer> | null | undefined

Inherited from: SublayersOwner

Since: ArcGIS Maps SDK for JavaScript 4.30

A flat Collection of all the tables in the layer including the tables of its sublayers. Apps can add them to a map as standalone tables.

Example

// Apps can add tables to a map as standalone tables
layer.subtables.forEach((subtable) => {
  const featureLayer = await subtable.createFeatureLayer();
  map.tables.add(featureLayer);
});

timeExtent

autocast inherited Property

Type: TimeExtent | null | undefined

Inherited from: TemporalLayer

Since: ArcGIS Maps SDK for JavaScript 4.14

The layer's time extent. When the layer's useViewTime is false, the layer instructs the view to show data from the layer based on this time extent. If the useViewTime is true, and both layer and view time extents are set, then features that fall within the intersection of the view and layer time extents will be displayed. For example, if the layer's time extent is set to display features between 1970 and 1975 and the view has a time extent set to 1972-1980, the effective time on the feature layer will be 1972-1975.

Examples

if (!layer.useViewTime) {
  if (layer.timeExtent) {
    console.log("Current timeExtent:", layer.timeExtent.start, " - ", layer.timeExtent.end}
  } else {
    console.log("The layer will display data within the view's timeExtent.");
    console.log("Current view.timeExtent:", view.timeExtent.start, " - ", view.timeExtent.end}
  }
}

// set the timeExtent on the layer and useViewTime false
// In this case, the layer will honor its timeExtent and ignore
// the view's timeExtent
const layer = new ImageryLayer({
  url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/ScientificData/SeaTemperature/ImageServer",
  timeExtent: {
    start: new Date(2014, 4, 18),
    end: new Date(2014, 4, 19)
  },
  useViewTime: false
});

// timeExtent is set on the layer and the view
// In this case, the layer will display features that fall
// within the intersection of view and layer time extents
// features within Jan 1, 1976 - Jan 1, 1981 will be displayed
const view = new MapView({
  timeExtent: {
    start: new Date(1976, 0, 1),
    end: new Date(2002, 0, 1)
  }
});
const layer = new FeatureLayer({
  url: myUrl,
  timeExtent: {
    start: new Date(1974, 0, 1),
    end: new Date(1981, 0, 1)
  }
});

timeInfo

autocast inherited Property

Type: TimeInfo | null | undefined

Inherited from: TemporalLayer

Since: ArcGIS Maps SDK for JavaScript 4.11

TimeInfo provides information such as date fields that store start and end time for each feature and the fullTimeExtent for the layer. The timeInfo property, along with its startField and endField properties, must be set at the time of layer initialization if it is being set for a CSVLayer, GeoJSONLayer or FeatureLayer initialized from client-side features. The fullTimeExtent for timeInfo is automatically calculated based on its startField and endField properties. The timeInfo parameters cannot be changed after the layer is loaded.

TimeInfo's TimeInfo.startField and endField can be date, date-only or timestamp-offset field type for FeatureLayer and MapImageLayer.

Example

// create geojson layer from usgs earthquakes geojson feed
const geojsonLayer = new GeoJSONLayer({
  url: "https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson",
  copyright: "USGS Earthquakes",
  fields: [
    { "name": "mag", "type": "double" },
    { "name": "place", "type": "string" },
    { "name": "time", "type": "date" }, // date field
    { "name": "depth", "type": "double" }
  ],
  // timeInfo can be used to do temporal queries
  // set the startField and endField.
  // timeExtent is automatically calculated from the
  // the start and end date fields
  // The date values must be in milliseconds number from the UNIX epoch specified in UTC.
  timeInfo: {
    startField: "time"
  }
});

timeOffset

autocast inherited Property

Type: TimeInterval | null | undefined

Inherited from: TemporalLayer

Since: ArcGIS Maps SDK for JavaScript 4.14

A temporary offset of the time data based on a certain TimeInterval. This allows users to overlay features from two or more time-aware layers with different time extents. For example, if a layer has data recorded for the year 1970, an offset value of 2 years would temporarily shift the data to 1972. You can then overlay this data with data recorded in 1972. A time offset can be used for display purposes only. The query and selection are not affected by the offset.

Example

// Offset a CSV Layer containing hurricanes from 2015 so that they appear in 2019 (+4 years).
let layer = new CSVLayer({
  url: `hurricanes-and-storms-2015.csv`,
  timeOffset: {
    value: 4,
    unit: "years"
  },
  timeInfo: {
    startField: "ISO_time"
  },
  renderer: {
    type: "simple",
    symbol: {
      type: "simple-marker",
      size: 6,
      color: "red",
      outline: {
        width: 0.5,
        color: "black"
      }
    }
  }
});

title

Property

Type: string | null | undefined

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

When loading a layer by service url, the title is derived from the service name. The titles for the sublayers will be the same as the names of the sublayers in the service. 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

readonly Property

Type: "map-image"

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.

url

Property

Type: string | null | undefined

The URL to the REST endpoint of the map service.

Example

// Layer from Map Service on ArcGIS Server
layer.url = "http://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer";

useViewTime

inherited Property

Type: boolean

Inherited from: TemporalLayer

Since: ArcGIS Maps SDK for JavaScript 4.14

Determines if the time enabled layer will update its temporal data based on the view's timeExtent. When false, the layer will display its temporal data based on the layer's timeExtent, regardless of changes to the view. If both view and layer time extents are set while this property is true, then the features that fall within the intersection of the view and layer time extents will be displayed. For example, if a layer's time extent is set to display features between 1970 and 1975 and the view has a time extent set to 1972-1980, the effective time on the feature layer will be 1972-1975.

Changing useViewTime to false does not affect layer's visibilityTimeExtent.

Default value: true

Example

if (featureLayer.useViewTime) {
  console.log("Displaying data between:", view.timeExtent.start, " - ", view.timeExtent.end);
}

version

readonlyinherited Property

Type: number

Inherited from: ArcGISMapService

The version of ArcGIS Server in which the map service is published.

Example

// Prints the version number to the console - e.g. 10.91, 11.2, 11.3.
console.log(layer.version);

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
`cancelLoad` inherited	`cancelLoad(): this`	LoadableMixin
`createExportImageParameters`	`createExportImageParameters(extent: Extent \| null \| undefined, width: number, height: number, options?: Omit<FetchImageOptions, "signal">): object`
`createLayerView` inherited	`createLayerView<T extends LayerView = LayerView>(view: View<T>, options?: AbortOptions): Promise<T>`	Layer
`createServiceSublayers` inherited	`createServiceSublayers(): Collection<Sublayer>`	SublayersOwner
`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
`fetchImage`	`fetchImage(extent: Extent, width: number, height: number, options?: FetchImageOptions): Promise<HTMLImageElement>`
`findSublayerById` inherited	`findSublayerById(id: number): Sublayer \| null \| undefined`	SublayersOwner
`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
`loadAll`	`loadAll(): Promise<this>`
`on` inherited	`on<Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle`	EventedMixin
`refresh` inherited	`refresh(): void`	RefreshableLayer
`save`	`save(options?: LayerSaveOptions): Promise<PortalItem>`
`saveAs`	`saveAs(portalItem: PortalItemProperties, options?: LayerSaveAsOptions): Promise<PortalItem>`
`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);
    }
  });
});

cancelLoad

inherited Method

Signature: cancelLoad (): this

Inherited from: LoadableMixin

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

Returns: this

createExportImageParameters

Method

Signature: createExportImageParameters (extent: Extent | null | undefined, width: number, height: number, options?: Omit<FetchImageOptions, "signal">): object

Gets the parameters of the exported image to use when calling the export REST operation.

Parameters

Parameter	Type	Description
extent	`Extent \| null \| undefined`	The extent of the exported image
width	`number`	The width of the exported image
height	`number`	The height of the exported image
options	`Omit<FetchImageOptions, "signal">`	The parameter options is an object with the following properties.

Returns: object
The parameters of the exported image. Use this object to call the export REST operation against the map service.

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.

createServiceSublayers

inherited Method

Signature: createServiceSublayers (): Collection<Sublayer>

Inherited from: SublayersOwner

Returns a deep clone of a map service's sublayers as defined by the service. This is useful for scenarios when the developer is unfamiliar with the service sublayers and needs to "reset" the layer's sublayers to match those defined by the service.

Returns: Collection<Sublayer>
A collection of sublayers as defined by the map service.

Example

Layer.fromPortalItem({
  portalItem: {
    portalId: "dbb9b48477444015912061b182f196b9"
  }
}).then(function(layer){
  let serviceSublayers = layer.createServiceSublayers();
  layer.sublayers = serviceSublayers;
});

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.

fetchImage

Method

Signature: fetchImage (extent: Extent, width: number, height: number, options?: FetchImageOptions): Promise<HTMLImageElement>

This method fetches the image for the specified extent and size.

Parameters

Parameter	Type	Description
extent	`Extent`	The extent of the view.
width	`number`	The width of the view in pixels.
height	`number`	The height of the view in pixels.
options	`FetchImageOptions`	The parameter options is an object with the following properties.

Returns: Promise<HTMLImageElement>
Returns a promise that resolves to an HTMLImageElement.

Example

// Fetch an image for the layer from the server for a given extent, height, width.
layer.when(function(){
  layer.fetchImage(view.extent, view.width, view.height).then(function(result){
    imageDiv.appendChild(result);
  });
});

findSublayerById

inherited Method

Signature: findSublayerById (id: number): Sublayer | null | undefined

Inherited from: SublayersOwner

Returns the sublayer with the given layerId.

Parameters

Parameter	Type	Description	Required
id	`number`	The Sublayer.id of the sublayer.

Returns: Sublayer | null | undefined
Returns the sublayer at the given layer ID.

Example

// returns the sublayer with a layerId of 0
let sublayer0 = layer.findSublayerById(0);

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.

loadAll

Method

Signature: loadAll (): Promise<this>

Since: ArcGIS Maps SDK for JavaScript 4.15

Loads all of the sublayers and subtables. See loaded or loadStatus properties to check the status.

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
mapImageLayer.loadAll()
  .catch(function(error) {
    // Ignore any failed resources
  })
  .then(function() {
    console.log("All 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);
});

refresh

inherited Method

Signature: refresh (): void

Inherited from: RefreshableLayer

Since: ArcGIS Maps SDK for JavaScript 4.6

Fetches all the data for the layer.

See also

Returns: void

save

Method

Signature: save (options?: LayerSaveOptions): Promise<PortalItem>

Since: ArcGIS Maps SDK for JavaScript 4.33

Saves the layer to its existing portal item in the Portal authenticated within the user's current session. If the layer is not saved to a PortalItem, then you should use saveAs().

Known Limitation

This method does not support saving cached map services.

Parameters

Parameter	Type	Description	Required
options	`LayerSaveOptions`	Various options for saving the layer.

Returns: Promise<PortalItem>
When resolved, returns the portal item to which the layer is saved.

Example

const portalItem = await layer.save();

saveAs

Method

Signature: saveAs (portalItem: PortalItemProperties, options?: LayerSaveAsOptions): Promise<PortalItem>

Since: ArcGIS Maps SDK for JavaScript 4.33

Saves the layer to a new portal item in the Portal authenticated within the user's current session.

Known Limitation

This method does not support saving cached map services.

Parameters

Parameter	Type	Description	Required
portalItem	`PortalItemProperties`	The portal item to which the layer will be saved.
options	`LayerSaveAsOptions`	Various options for saving the layer.

Returns: Promise<PortalItem>
When resolved, returns the portal item to which the layer is saved.

Example

const portalItem = new PortalItem();
await layer.saveAs(portalItem);

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>
`refresh` inherited	CustomEvent<RefreshEvent>

layerview-create

inherited Event

layerview-create: CustomEvent<LayerLayerviewCreateEvent>

Inherited from: LayerEvents

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: LayerEvents

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: LayerEvents

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

refresh

inherited Event

refresh: CustomEvent<RefreshEvent>

Inherited from: RefreshableLayerEvents

Since: ArcGIS Maps SDK for JavaScript 4.21

Fires if the layer has the refreshInterval set or when refresh() method is called. The event payload indicates if the layer's data has changed.

See also

Examples

// listen to layer's refresh event to fetch the attachments
// for the updated features.
layer.on("refresh", async (event) =>{
  if (!event.dataChanged){
    return;
  }

  try {
    const query = layer.createQuery();
    const objectIds = await layer.queryObjectIds(query);
    let attachmentQuery = {
      objectIds: objectIds,
      definitionExpression: layer.definitionExpression,
      attachmentTypes: ["image/jpeg"]
    };

    const attachments = await layer.queryAttachments(attachmentQuery);

    attachmentQuery.objectIds.forEach(function (objectId) {
      if (attachments[objectId]) {
        // process the updated attachments
        let attachment = attachments[objectId];
        console.log("Attachments for objectId ", objectId, attachment);
      }
    });
  } catch (error) {
    console.log("attachment query error", error);
  }
});

// listen to layer's refresh event to fetch object ids of completed features
layer.on("refresh", function(event){
  if (event.dataChanged){
    const query = layer.createQuery();
    query.where = "Status = 'Completed'";
    layer.queryObjectIds(query).then((objectIds) => {
     // process returned features
    });
  }
});

Type definitions

MapImageLayerImageFormat

Type definition

Type: "png" | "png8" | "png24" | "png32" | "jpg" | "pdf" | "bmp" | "gif" | "pngjpg"