MapImageLayer | API Reference | ArcGIS Maps SDK for JavaScript 4.30

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.

require(["esri/layers/MapImageLayer"], function(MapImageLayer){
  // 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 on terms of use, see the Terms of Use FAQ.

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

MapImageLayer Constructor new MapImageLayer(properties)

Parameter

properties Object

optional

See the properties 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: [ {}, {}, {} ]
});

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.

Show inherited properties

Hide inherited properties

Type	Summary	Class
Collection<Sublayer>	A flat Collection of all the sublayers in the MapImageLayer including the sublayers of its sublayers.	MapImageLayer
String	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.	MapImageLayer
Object	Indicates the layer's supported capabilities.	MapImageLayer
String	The copyright text as defined by the service.	MapImageLayer
Object\|null\|undefined	A list of custom parameters appended to the URL of all resources fetched by the layer.	MapImageLayer
String	The time zone that dates are stored in.	MapImageLayer
Boolean	This property is set by the service publisher and indicates that dates should be considered without the local timezone.	MapImageLayer
String	The name of the class.	Accessor
Number	The output dots per inch (DPI) of the MapImageLayer.	MapImageLayer
Effect\|null\|undefined	Effect provides various filter functions that can be performed on the layer to achieve different visual effects similar to how image filters work.	MapImageLayer
Extent	The full extent of the layer as defined by the map service.	MapImageLayer
String	The version of the geodatabase of the map service data.	MapImageLayer
String	The unique ID assigned to the layer.	Layer
String	The output image type.	MapImageLayer
Number	Indicates the maximum height of the image exported by the service.	MapImageLayer
Number	Indicates the maximum width of the image exported by the service.	MapImageLayer
Boolean	Indicates whether the background of the image exported by the service is transparent.	MapImageLayer
Boolean	Indicates whether the layer will be included in the legend.	MapImageLayer
String	Indicates how the layer should display in the LayerList widget.	Layer
Boolean	Indicates whether the layer's resources have loaded.	MapImageLayer
Error	The Error object returned if an error occurred while loading.	Layer
String	Represents the status of a load operation.	Layer
Object []	A list of warnings which occurred while loading.	Layer
Number	The maximum scale (most zoomed in) at which the layer is visible in the view.	MapImageLayer
Number	The minimum scale (most zoomed out) at which the layer is visible in the view.	MapImageLayer
Number	The opacity of the layer.	Layer
Map\|Basemap\|Ground\|GroupLayer\|CatalogDynamicGroupLayer\|CatalogLayer	The parent to which the layer belongs.	Layer
Boolean	Enable persistence of the layer in a WebMap or WebScene.	MapImageLayer
PortalItem\|null\|undefined	The portal item from which the layer is loaded.	MapImageLayer
String	The IANA time zone the author of the service intended data from date fields to be viewed in.	MapImageLayer
Number	Refresh interval of the layer in minutes.	MapImageLayer
Object	The map service's metadata JSON exposed by the ArcGIS REST API.	MapImageLayer
SpatialReference	The spatial reference of the layer as defined by the service.	MapImageLayer
Collection<Sublayer>	A Collection of Sublayer objects that allow you to alter the properties of one or more sublayers of the MapImageLayer.	MapImageLayer
Collection<Sublayer>	A flat Collection of all the tables in the layer including the tables of its sublayers.	MapImageLayer
TimeExtent\|null\|undefined	The layer's time extent.	MapImageLayer
TimeInfo\|null\|undefined	TimeInfo provides information such as date fields that store start and end time for each feature and the fullTimeExtent for the layer.	MapImageLayer
TimeInterval\|null\|undefined	A temporary offset of the time data based on a certain TimeInterval.	MapImageLayer
String\|null\|undefined	The title of the layer used to identify it in places such as the Legend and LayerList widgets.	MapImageLayer
String	For MapImageLayer the type is always "map-image".	MapImageLayer
String	The URL to the REST endpoint of the map service.	MapImageLayer
Boolean	Determines if the time enabled layer will update its temporal data based on the view's timeExtent.	MapImageLayer
Number	The version of ArcGIS Server in which the map service is published.	MapImageLayer
TimeExtent\|null\|undefined	Specifies a fixed time extent during which a layer should be visible.	Layer
Boolean	Indicates if the layer is visible in the View.	Layer

Property Details

allSublayers Property allSublayers Collection<Sublayer>readonly

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;
});

blendMode Property blendMode String Since: ArcGIS Maps SDK for JavaScript 4.16 MapImageLayer since 4.0, blendMode added at 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

The blendMode in 3D SceneViews is supported on BaseTileLayer, ImageryTileLayer, OpenStreetMapLayer, TileLayer, VectorTileLayer, WCSLayer, WebTileLayer, WMTSLayer and GroupLayer.
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 terrain basemap 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.

Default Value:normal

See also

Layer blending samples

capabilities Property capabilities Objectreadonly Since: ArcGIS Maps SDK for JavaScript 4.8 MapImageLayer since 4.0, capabilities added at 4.8.

Indicates the layer's supported capabilities.

Properties

exportMap Object|null|undefined

Indicates options supported by the exportMap operation. Will be null if the supportsExportMap is false.

Specification: supportsArcadeExpressionForLabeling Boolean

Indicates if sublayers support Arcade expressions for labeling. Only applies to MapImageLayer. This has been available since version 4.19.

supportsDynamicLayers Boolean

Indicates if sublayers rendering can be modified or added using dynamic layers.

supportsSublayersChanges Boolean

Indicates if sublayers can be added, or removed. supportsDynamicLayers must be true as well to be able to reorder sublayers.

supportsSublayerDefinitionExpression Boolean

Indicates if sublayers definition expression can be set.

supportsSublayerVisibility Boolean

Indicates if sublayers visibility can be changed.

supportsCIMSymbols Boolean

Since 4.23 Indicates if CIMSymbol can be used in a sublayer's renderer.

exportTiles Object|null|undefined

Indicates options supported by the exportTiles operation. Will be null if the supportsExportTiles is false.

Specification: maxExportTilesCount Number

Specifies the maximum number of tiles that can be exported to a cache dataset or a tile package.

operations Object

Indicates operations that can be performed on the service.

Specification: supportsExportMap Boolean

Indicates if the service can generate images.

supportsExportTiles Boolean

Indicates if the tiles from the service can be exported.

supportsIdentify Boolean

Indicates if the service supports the identify operation.

supportsQuery Boolean

Indicates if features in the sublayers can be queried.

supportsTileMap Boolean

Indicates if the service exposes a tile map that describes the presence of tiles.

copyright Property copyright String

The copyright text as defined by the service.

customParameters Property customParameters Object |null |undefined Since: ArcGIS Maps SDK for JavaScript 4.18 MapImageLayer since 4.0, customParameters added at 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 Property dateFieldsTimeZone Stringreadonly Since: ArcGIS Maps SDK for JavaScript 4.28 MapImageLayer since 4.0, dateFieldsTimeZone added at 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 FieldIndex.getTimeZone() to get the time zone for the given date field.

See also

datesInUnknownTimezone Property datesInUnknownTimezone Booleanreadonly Since: ArcGIS Maps SDK for JavaScript 4.21 MapImageLayer since 4.0, datesInUnknownTimezone added at 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, 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.

Default Value:false

See also

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

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

dpi Property dpi Number

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

Default Value:96

effect Property effect Effect |null |undefinedautocast Since: ArcGIS Maps SDK for JavaScript 4.18 MapImageLayer since 4.0, effect added at 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 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 featureReduction of type cluster enabled.
See print for known printing limitations.

Default Value:null

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 Property fullExtent Extent

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 gdbVersion String

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 id 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 imageFormat String

The output image type.

Possible Values:"png" |"png8" |"png24" |"png32" |"jpg" |"pdf" |"bmp" |"gif" |"svg" |"pngjpg"

Default Value:png24

imageMaxHeight Property imageMaxHeight Number Since: ArcGIS Maps SDK for JavaScript 4.3 MapImageLayer since 4.0, imageMaxHeight added at 4.3.

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

Default Value:2048

imageMaxWidth Property imageMaxWidth Number Since: ArcGIS Maps SDK for JavaScript 4.3 MapImageLayer since 4.0, imageMaxWidth added at 4.3.

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

Default Value:2048

imageTransparency Property imageTransparency Boolean

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

Default Value:true

legendEnabled Property legendEnabled Boolean

Indicates whether the layer will be included in the legend.

Default Value:true

listMode Inherited Property listMode String Inherited from Layer

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 Property loaded Booleanreadonly

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

Default Value:false

loadError Inherited Property loadError Errorreadonly Inherited from Layer

The Error object returned if an error occurred while loading.

Default Value:null

loadStatus Inherited Property loadStatus Stringreadonly Inherited from Layer

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 Inherited Property loadWarnings Object[]readonly Inherited from Layer

A list of warnings which occurred while loading.

maxScale Property maxScale Number

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 Property minScale Number

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 opacity 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.

Default Value:1

Example

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

The parent to which the layer belongs.

persistenceEnabled Property persistenceEnabled Boolean Since: ArcGIS Maps SDK for JavaScript 4.28 MapImageLayer since 4.0, persistenceEnabled added at 4.28.

Enable persistence of the layer in a WebMap or WebScene.

Default Value:true

portalItem Property portalItem 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.

Example

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

preferredTimeZone Property preferredTimeZone Stringreadonly Since: ArcGIS Maps SDK for JavaScript 4.28 MapImageLayer since 4.0, preferredTimeZone added at 4.28.

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

Default Value:null

See also

Wikipedia - List of tz database time zones

refreshInterval Property refreshInterval Number Since: ArcGIS Maps SDK for JavaScript 4.6 MapImageLayer since 4.0, refreshInterval added at 4.6.

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

Default Value:0

See also

refresh()
refresh event

Example

// the layer will be refreshed every 6 seconds.
layer.refreshInterval = 0.1;

sourceJSON Property sourceJSON Object Since: ArcGIS Maps SDK for JavaScript 4.13 MapImageLayer since 4.0, sourceJSON added at 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 Property spatialReference SpatialReferencereadonly

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

sublayers Property sublayers Collection<Sublayer>autocast Autocasts from Object []

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 Property subtables Collection<Sublayer> Since: ArcGIS Maps SDK for JavaScript 4.30 MapImageLayer since 4.0, subtables added at 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 Property timeExtent TimeExtent |null |undefinedautocast Since: ArcGIS Maps SDK for JavaScript 4.14 MapImageLayer since 4.0, timeExtent added at 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.

Default Value:null

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 Property timeInfo TimeInfo |null |undefinedautocast Since: ArcGIS Maps SDK for JavaScript 4.11 MapImageLayer since 4.0, timeInfo added at 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 startField and endField can be date, date-only or timestamp-offset field type for FeatureLayer and MapImageLayer.

Default Value:null

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 Property timeOffset TimeInterval |null |undefinedautocast Since: ArcGIS Maps SDK for JavaScript 4.14 MapImageLayer since 4.0, timeOffset added at 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.

Default Value:null

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 title String |null |undefined

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

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 Property type Stringreadonly

For MapImageLayer the type is always "map-image".

url Property url String

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 Property useViewTime Boolean Since: ArcGIS Maps SDK for JavaScript 4.14 MapImageLayer since 4.0, useViewTime added at 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 Property version Numberreadonly

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

Example

// Prints the version number to the console, e.g. 10.2, 10.3, 10.41.
console.log(layer.version);

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

Specifies a fixed time extent during which a layer should be visible. This property can be used to configure a layer that does not have time values stored in an attribute field to work with time. Once configured, the TimeSlider widget will display the layer within the set time extent. In the case that only one of the start or end date values are available, the layer remains visible indefinitely in the direction where there is no time value.

Aerial imagery can capture seasonal variations in vegetation, water bodies, and land use patterns. For example, in agricultural regions, aerial imageries taken during different growing seasons provide insights into crop health and productivity. Defining a fixed time extent on imageries from specific time periods provides temporal context and facilitates focused analysis based on specific time periods or events.

Default Value:null

See also

Sample - GraphicsLayer with visibilityTimeExtent

visible Inherited Property visible 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;

Method Overview

Show inherited methods

Hide inherited methods

Return Type	Summary	Class
	Adds one or more handles which are to be tied to the lifecycle of the object.	Accessor
	Cancels a load() operation if it is already in progress.	Layer
Object	Gets the parameters of the exported image to use when calling the export REST operation.	MapImageLayer
Promise<LayerView>	Called by the views, such as MapView and SceneView, when the layer is added to the Map.layers collection and a layer view must be created for it.	Layer
Collection<Sublayer>	Returns a deep clone of a map service's sublayers as defined by the service.	MapImageLayer
	Destroys the layer and any associated resources (including its portalItem, if it is a property on the layer).	Layer
Boolean	Emits an event on the instance.	Layer
Promise<object>	Fetches custom attribution data for the layer when it becomes available.	Layer
Promise<HTMLImageElement>	This method fetches the image for the specified extent and size.	MapImageLayer
Sublayer	Returns the sublayer with the given layerId.	MapImageLayer
Boolean	Indicates whether there is an event listener on the instance that matches the provided event name.	Layer
Boolean	Returns true if a named group of handles exist.	Accessor
Boolean	`isFulfilled()` may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected).	Layer
Boolean	`isRejected()` may be used to verify if creating an instance of the class is rejected.	Layer
Boolean	`isResolved()` may be used to verify if creating an instance of the class is resolved.	Layer
Promise	Loads the resources referenced by this class.	Layer
Promise<Sublayer>	Loads all of the sublayers and subtables.	MapImageLayer
Object	Registers an event handler on the instance.	Layer
	Fetches all the data for the layer.	MapImageLayer
	Removes a group of handles owned by the object.	Accessor
Promise	`when()` may be leveraged once an instance of the class is created.	Layer

Method Details

addHandles Inherited Method addHandles(handleOrHandles, groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, addHandles added at 4.25.

Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.

// Manually manage handles
const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true }
);

this.addHandles(handle);

// Destroy the object
this.destroy();

Parameters

handleOrHandles WatchHandle|WatchHandle []

Handles marked for removal once the object is destroyed.

groupKey *

optional

Key identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.

cancelLoad Inherited Method cancelLoad() Inherited from Layer

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

createExportImageParameters Method createExportImageParameters(extent, width, height, options){Object}

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

Parameters

Specification

extent Extent

The extent of the exported image

width Number

The width of the exported image

height Number

The height of the exported image

options Object

optional

The parameter options is an object with the following properties.

Specification

rotation Number

optional

The rotation in degrees of the exported image. Available since ArcGIS Server 10.3.

pixelRatio Number

optional

The pixel ratio to apply to the dpi of the exported image.

timeExtent TimeExtent

optional

The time instant or time extent of content to render.

Returns

Type	Description
Object	The parameters of the exported image. Use this object to call the export REST operation against the map service.

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

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

createServiceSublayers Method createServiceSublayers(){Collection<Sublayer>}

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

Type	Description
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 destroy() Inherited from Layer Since: ArcGIS Maps SDK for JavaScript 4.17 Layer since 4.0, destroy added at 4.17.

Destroys the layer and any associated resources (including its portalItem, if it is a property on the layer). The layer can no longer be used once it has been destroyed.

The destroyed layer will be removed from its parent object like Map, WebMap, WebScene, Basemap, Ground, or GroupLayer.

See also

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

Emits an event on the instance. This method should only be used when creating subclasses of this class.

Parameters

type String

The name of the event.

event Object

optional

The event payload.

Returns

Type	Description
Boolean	`true` if a listener was notified

fetchAttributionData Inherited Method fetchAttributionData(){Promise<object>} Inherited from Layer

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.

fetchImage Method fetchImage(extent, width, height, options){Promise<HTMLImageElement>}

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

Parameters

Specification

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 Object

optional

The parameter options is an object with the following properties.

Specification

rotation Number

optional

The rotation in degrees of the exported image. Available since ArcGIS Server 10.3.

pixelRatio Number

optional

The ratio of the resolution in physical pixels of the image to the resolution it will be displayed at.

timeExtent TimeExtent

optional

The time instant or time extent of content to render.

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<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 Method findSublayerById(id){Sublayer}

Returns the sublayer with the given layerId.

Parameter

id Number

The id of the sublayer.

Returns

Type	Description
Sublayer	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 hasEventListener(type){Boolean} Inherited from Layer

Indicates whether there is an event listener on the instance that matches the provided event name.

Parameter

type String

The name of the event.

Returns

Type	Description
Boolean	Returns true if the class supports the input event.

hasHandles Inherited Method hasHandles(groupKey){Boolean} Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, hasHandles added at 4.25.

Returns true if a named group of handles exist.

Parameter

groupKey *

optional

A group key.

Returns

Type	Description
Boolean	Returns `true` if a named group of handles exist.

Example

// Remove a named group of handles if they exist.
if (obj.hasHandles("watch-view-updates")) {
  obj.removeHandles("watch-view-updates");
}

isFulfilled Inherited Method isFulfilled(){Boolean} Inherited from Layer

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 Inherited Method isRejected(){Boolean} Inherited from Layer

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 Inherited Method isResolved(){Boolean} Inherited from Layer

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 Inherited Method load(signal){Promise} Inherited from Layer

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.

loadAll Method loadAll(){Promise<Sublayer>} Since: ArcGIS Maps SDK for JavaScript 4.15 MapImageLayer since 4.0, loadAll added at 4.15.

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

Returns

Type	Description
Promise<Sublayer>	Resolves when all the loadable resources have been loaded. Rejects if at least one of the loadable resources failed to load.

See also

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 on(type, listener){Object} Inherited from Layer

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);
});

refresh Method refresh() Since: ArcGIS Maps SDK for JavaScript 4.6 MapImageLayer since 4.0, refresh added at 4.6.

Fetches all the data for the layer.

See also

refreshInterval
refresh event

removeHandles Inherited Method removeHandles(groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, removeHandles added at 4.25.

Removes a group of handles owned by the object.

Parameter

groupKey *

optional

A group key or an array or collection of group keys to remove.

Example

obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");

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

when() may be leveraged once an instance of the class is created. This method takes two input parameters: a callback function and an errback function. The callback executes when the instance of the class loads. The errback executes if the instance of the class fails to load.

Parameters

callback Function

optional

The function to call when the promise resolves.

errback Function

optional

The function to execute when the promise fails.

Returns

Type	Description
Promise	Returns a new promise for the result of `callback` that may be used to chain additional functions.

Example

// Although this example uses MapView, any class instance that is a promise may use when() in the same way
let view = new MapView();
view.when(function(){
  // This function will execute once the promise is resolved
}, function(error){
  // This function will execute if the promise is rejected due to an error
});

Event Overview

Show inherited events

Hide inherited events

Type	Summary	Class
{view: View,layerView: LayerView}	Fires after the layer's LayerView is created and rendered in a view.	Layer
{view: View,error: Error}	Fires when an error emits during the creation of a LayerView after a layer has been added to the map.	Layer
{view: View,layerView: LayerView}	Fires after the layer's LayerView is destroyed and no longer renders in a view.	Layer
{dataChanged: Boolean}	Fires if the layer has the refreshInterval set or when refresh() method is called.	MapImageLayer

Event Details

layerview-create Inherited Event layerview-create Inherited from Layer

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

Properties

view View

The view in which the layerView was created.

layerView LayerView

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

See also

View.whenLayerView()

Example

// This function will fire each time a layer view is created for this
// particular view.
layer.on("layerview-create", function(event){
  // The LayerView for the layer that emitted this event
  event.layerView;
});

layerview-create-error Inherited Event layerview-create-error Inherited from Layer

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

Properties

view View

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

error Error

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

See also

View.whenLayerView()

Example

// This function fires when an error occurs during the creation of the layer's layerview
layer.on("layerview-create-error", function(event) {
  console.error("LayerView failed to create for layer with the id: ", layer.id, " in this view: ", event.view);
});

layerview-destroy Inherited Event layerview-destroy Inherited from Layer

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.

refresh Event refresh Since: ArcGIS Maps SDK for JavaScript 4.21 MapImageLayer since 4.0, refresh added at 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.

Property

dataChanged Boolean

Indicates if the layer's data has changed.

See also

refreshInterval
refresh()

Example

// listen to layer's refresh event to fetch the attachments
// for the updated features.
layer.on("refresh", function(event){
  if (event.dataChanged){
    const query = layer.createQuery();
    layer.queryObjectIds(query).then(function (objectIds) {
      let attachmentQuery = {
        objectIds: objectIds,
        definitionExpression: layer.definitionExpression,
        attachmentTypes: ["image/jpeg"]
      };
      layer.queryAttachments(attachmentQuery).then(function (attachments) {
        attachmentQuery.objectIds.forEach(function (objectId) {
          if (attachments[objectId]) {
            // process the updated attachments
            let attachment = attachments[objectId];
          }
        });
      })
      .catch(function (error) {
        console.log("attachment query error", error);
      });
    });
  }
});