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import GeoJSONLayer from "@arcgis/core/layers/GeoJSONLayer.js";
Inheritance:
GeoJSONLayerLayerAccessor
Since
ArcGIS Maps SDK for JavaScript 4.11

Overview

The GeoJSONLayer class is used to create a layer based on GeoJSON. GeoJSON is a format for encoding a variety of geographic data structures. The GeoJSON data must comply with the RFC 7946 specification which states that the coordinates are in SpatialReference.WGS84. Refer to FeatureLayer's querying your data section to learn more about how to query your geojson data, and the data visualization section to learn how to change the GeoJSONLayer's visualization.

Please see the table below for supported geometry objects from GeoJSON and their corresponding geometry types:

GeoJSON Geometry ObjectAPI Geometry Type
PointPoint
MultiPointMultipoint
LineString/MultiLineStringPolyline
Polygon/MultiPolygonPolygon

Creating a GeoJSONLayer

GeoJSONLayer is created by setting its url property to point to geojson feed or to a blob url for in memory geojson data.

Reference a geojson feed URL

To create a GeoJSONLayer instance from a geojson feed, you must set the url property to the url of the geojson feed.

const GeoJSONLayer = await $arcgis.import("@arcgis/core/layers/GeoJSONLayer.js");
// points to the states layer in a service storing U.S. census data
const geojsonlayer = new GeoJSONLayer({
url: "https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson",
copyright: "USGS Earthquakes"
});
map.add(geojsonlayer); // adds the layer to the map

Reference in memory geojson data by a blob url

You can also create a GeoJSONLayer from in memory geojson data by passing a blob url to the url property of the layer. The following snippet shows how to create a new GeoJSONLayer from a blob url.

// create a geojson layer from geojson feature collection
const geojson = {
type: "FeatureCollection",
features: [
{
type: "Feature",
id: 1,
geometry: {
type: "Polygon",
coordinates: [
[
[100.0, 0.0],
[101.0, 0.0],
[101.0, 1.0],
[100.0, 1.0],
[100.0, 0.0]
]
]
},
properties: {
type: "single",
recordedDate: "2018-02-07T22:45:00-08:00"
}
}
]
};
// create a new blob from geojson featurecollection
const blob = new Blob([JSON.stringify(geojson)], {
type: "application/json"
});
// URL reference to the blob
const url = URL.createObjectURL(blob);
// create new geojson layer using the blob url
const layer = new GeoJSONLayer({
url
});

Notes

Each GeoJSONLayer will only accept one geometry type. If there are multiple types of geometries, only the type specified in geometryType will be loaded. If geometryType is not specified, it will default to the geometry type of the first geometry. Each GeoJSONLayer will only accept one schema of the properties. The fields property can be used to specify the desired fields for the layer. If fields is not defined, the schema used by the first feature will be used to deduce the fields schema for the layer. GeometryCollection is not supported. Using Object as attribute value for GeoJSON features is not supported. Geometries that cross the Antimeridian line are not currently supported. Date fields will be created implicitly when GeoJSONLayer is loaded, if the geojson feature objects have properties containing date and time values such as ISO8601 date strings.

See also

Constructors

Constructor

Constructor
Parameters
ParameterTypeDescriptionRequired
properties
See the properties table for a list of all the properties that may be passed into the constructor.
Example
const geoJSONLayer = new GeoJSONLayer({
url: "https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson",
copyright: "USGS Earthquakes",
});
map.add(geoJSONLayer); // adds the layer to the map

Properties

Any properties can be set, retrieved or listened to. See the Watch for changes topic.
PropertyTypeClass
blendMode
inherited
capabilities
readonly
declaredClass
readonly inherited
displayFilterInfo
inherited
effect
inherited
featureEffect
inherited
featureReduction
inherited
Field[]
fieldsIndex
readonly
"point" | "polygon" | "polyline" | "multipoint" | null | undefined
hasZ
readonly
id
inherited
isTable
readonly
listMode
inherited
loaded
readonly inherited
loadError
readonly inherited
loadStatus
readonly inherited
"not-loaded" | "loading" | "failed" | "loaded"
loadWarnings
readonly inherited
any[]
maxScale
inherited
minScale
inherited
opacity
inherited
orderBy
inherited
parent
inherited
persistenceEnabled
inherited
trackInfo
inherited
type
readonly
"geojson"
uid
readonly inherited
url
visible
inherited

attributeTableTemplate

autocast Property
Type
AttributeTableTemplate | null | undefined
Since
ArcGIS Maps SDK for JavaScript 4.31

This property is used to configure the associated layer's FeatureTable. It is meant to configure how the columns display within the table in regard to visibility, column order, and sorting.

This property differs from the FeatureTable's tableTemplate property. The TableTemplate provides more fine-grained control over how the table is rendered within the application by offering more advanced configurations such as custom cell rendering, column formatting, and more. TableTemplate is useful for application-level development that remains within an application. Use the attributeTableTemplate property to access the table's settings across different applications. By using this property, the settings can be saved within a webmap or layer. Please refer to the AttributeTableTemplate and TableTemplate documentation for more information.

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.

color-blend

Known 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.
Read More
Blend modeDescription
normalThe top layer is displayed over the background layer. The data of the top layer block the data of background layer where they overlap.
averageTakes 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 modeDescription
lightenCompares 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.
lighterColors 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.
plusColors 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.
screenMultiplies 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-dodgeDivides 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 modeDescription
darkenEmphasizes 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.
multiplyEmphasizes 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-burnIntensifies 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 modeOverlay blend mode
no-blendmodeoverlay-blend
Blend modeDescription
overlayUses 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-lightApplies 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-lightMultiplies 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-lightUses 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.

color-blend
Blend modeDescription
hueCreates an effect with the hue of the top layer and the luminosity and saturation of the background layer.
saturationCreates 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.
luminosityCreates 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.
colorCreates 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).

destination-in
Blend modeDescription
destination-overDestination/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-atopDestination/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-inDestination/background layer is drawn only where it overlaps with the top layer. Everything else is made transparent.
destination-outDestination/background layer is drawn where it doesn't overlap the top layer. Everything else is made transparent.
source-atopSource/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-inSource/top layer is drawn only where it overlaps with the background layer. Everything else is made transparent.
source-outSource/top layer is drawn where it doesn't overlap the background layer. Everything else is made transparent.
xorTop 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.

color-blend
Blend modeDescription
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.
exclusionSimilar 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.
minusSubtracts 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.
invertInverts the background colors wherever the top and background layers overlap. The invert blend mode inverts the layer similar to a photographic negative.
reflectThis 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
Default value
"normal"

capabilities

readonly Property
Type
FeatureLayerCapabilities

Describes the layer's supported capabilities.

Example
// Once the layer loads, check if the supportsStatistics operations is enabled on the layer
await layer.load();
if (layer.capabilities.query.supportsStatistics) {
// query for the sum of the population in all features
let sumPopulation = {
onStatisticField: "POP_2015", // service field for 2015 population
outStatisticFieldName: "Pop_2015_sum",
statisticType: "sum"
}
let query = layer.createQuery();
query.outStatistics = [ sumPopulation ];
const result = await layer.queryFeatures(query);
// process the stats query result
}
Property
Type
string | null | undefined

Copyright information for the layer.

customParameters

Property
Type
CustomParameters | null | undefined
Since
ArcGIS Maps SDK for JavaScript 4.22

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.

See also
Examples
// set customParameters to request the top 3 earthquakes since 1900.
// The USGS earthquakes catalog returns earthquakes with specified query parameters.
const geojsonLayer = new GeoJSONLayer({
url: "https://earthquake.usgs.gov/fdsnws/event/1/query",
customParameters: {
format: "geojson",
starttime: "1900-01-01",
endtime: "2021-01-01",
minmagnitude: "8",
orderby:"magnitude",
limit: "3"
}
});
// 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. Time zone is always UTC for GeoJSONLayer. This property may be useful when constructing date or time where clauses.

declaredClass

readonlyinherited Property
Type
string
Inherited from: Accessor

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

definitionExpression

Property
Type
string | null | undefined

The SQL where clause used to filter features on the client. Only the features that satisfy the definition expression are displayed in the View. Definition expressions may be set when a layer is constructed prior to it loading in the view or after it has been added to the map. If the definition expression is set after the layer has been added to the map, the view will automatically refresh itself to display the features that satisfy the new definition expression.

Examples
// Set definition expression in constructor to only display earthquakes magnitude 5.0 and greater
const layer = new GeoJSONLayer({
url: "https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson",
definitionExpression: "mag >= 5"
});
// Set the definition expression directly on layer instance after it has loaded
layer.definitionExpression = "mag >= 5";

displayField

Property
Type
string | null | undefined

The name of the layer's primary display field. The value of this property matches the name of one of the fields of the layer.

displayFilterEnabled

inherited Property
Type
boolean
Inherited from: DisplayFilteredLayer
Since
ArcGIS Maps SDK for JavaScript 4.32

Indicates whether the layer's displayFilterInfo is applied when rendering the layer in the view. If false, the layer's display filter is ignored and all features are rendered without filtering. To ignore display filters across all layers in the view, set the view's View.displayFilterEnabled property to false.

Default value
true

displayFilterInfo

autocast inherited Property
Type
DisplayFilterInfo | null | undefined
Inherited from: DisplayFilteredLayer
Since
ArcGIS Maps SDK for JavaScript 4.32

Information related to a display filter associated with a layer. Display filters control which features are visible on the map. They allow you to display a subset of features while retaining access to all features for querying and analysis. Unlike FeatureLayer.definitionExpression, which filters data at the source level, display filters only affect visibility on the map. Therefore display filters should be ignored when querying data to present to users. Display filters can be disabled for all layers in the map by setting the view's View.displayFilterEnabled property to false.

Notes: To optimize memory usage for rendering, display filters may be appended to the layer's FeatureLayer.definitionExpression when querying the service. As a result, the filtered features may not be available on the client for executing layer view queries. To determine if all features are available in the view, check the layer view's FeatureLayerView.hasAllFeaturesInView property when layer view's FeatureLayerView.dataUpdating is false. If false, the layer view does not have all features in the view and you should query the layer instead.

See also
Example
// set a scale-dependent display filter on a layer
const layer = new FeatureLayer({
portalItem: {
id: "28dbd58ad90e4a47ab0e0334d2b69427"
},
minScale: 0,
maxScale: 0,
outFields: ["*"],
// set scale-dependent display filters to declutter the display at different scales.
// Show more streams as user zooms in and less as user zooms out.
displayFilterInfo: new DisplayFilterInfo({
mode: "scale",
filters: [
{
title: "streamOrder >= 8",
minScale: 0,
maxScale: 18_489_297.737236,
where: "streamOrder >= 8"
},
{
title: "streamOrder >= 6",
minScale: 18_489_297.737236
maxScale: 9_244_648.868618,
where: "streamOrder >= 6"
},
{
title: "streamOrder >= 4",
minScale: 9_244_648.868618,
maxScale: 577790.5542885
where: "streamOrder >= 4"
},
{
title: "all",
minScale: 577790.5542885,
maxScale: 0
}
]
})
});

editingEnabled

Property
Type
boolean
Since
ArcGIS Maps SDK for JavaScript 4.22

Indicates if the layer is editable. The GeoJSONLayer features are only editable in memory. The source geojson file is not modified when editing features. Therefore editingEnabled is false by default. If set to true, the source geojson file needs to be updated manually.

See also
Default value
false

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

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)"
}
];

elevationInfo

autocast Property
Type
ElevationInfo | null | undefined

Specifies how features are placed on the vertical axis (z). This property may only be used in a SceneView. See the ElevationInfo sample for an example of how this property may be used.

If the elevation info is not specified, the effective elevation depends on the context and could vary per graphic.

featureEffect

autocast inherited Property
Type
FeatureEffect | null | undefined
Inherited from: FeatureEffectLayer
Since
ArcGIS Maps SDK for JavaScript 4.22

The featureEffect can be used to draw attention to features of interest. It allows for the selection of features via a filter, and an includedEffect and excludedEffect are applied to those features that respectively pass or fail the filter requirements.

Notes

  • Set the effect property if the effect needs to be applied to the entire layer.
  • If the featureEffect is set on the layer, it will be inherited by layerView.featureEffect unless the developer overrides it on the layer view. The layerView.featureEffect will take precedence over layer.featureEffect if both properties are set.
  • If all of the following four properties are applied, then they will be applied in this order: featureEffect, effect, opacity and blendMode.

Known Limitations

FeatureEffect is not supported in the following scenarios:

See also
Examples
// gray out features that fall outside of the 3 mile buffer of the mouse's location
// by setting feature effect on excluded features
layer.featureEffect = new FeatureEffect({
filter: new FeatureFilter({
geometry: filterGeometry,
spatialRelationship: "intersects",
distance: 3,
units: "miles"
}),
excludedEffect: "grayscale(100%) opacity(30%)"
});
// Apply a drop-shadow feature effect to the features that intersect the borough boundaries,
// while applying blur and brightness effects to the features that are excluded from filter criteria.
// The resulting map will make it easier to spot if the residents are more likely to experience deprivation
// if they live on a borough boundary.
const featureFilter = new FeatureFilter({
where: "BoroughEdge='true'"
});
layer.featureEffect = new FeatureEffect({
filter: featureFilter,
includedEffect: "drop-shadow(3px, 3px, 3px, black)",
excludedEffect: "blur(1px) brightness(65%)"
});

featureReduction

autocast inherited Property
Type
FeatureReductionUnion | null | undefined
Inherited from: FeatureReductionLayer

Configures the method for reducing the number of features in the view. By default this property is null, which indicates the layer view should draw every feature.

There are three types of feature reduction: selection, cluster, and binning.

  • Selection only applies to points in a SceneView and involves thinning overlapping features so no features intersect on screen. This has been available since version 4.4.
  • Cluster groups points, lines, or polygons in a MapView into clusters defined in screen space. Each cluster is a point geometry whose size is proportional to the number of features within the cluster. This has been available since version 4.14.
  • Binning spatially groups points, lines, or polygons in a MapView into bins, clearly defining the area aggregating features in map space. Each bin is a polygon geometry typically rendered so its color represents the number of features within the bin. This has been available since version 4.24.
See also
Examples
// clusters features based on their spatial proximity to other features
layer.featureReduction = {
type: "cluster",
clusterRadius: 100
};
// thins features in the view
layer.featureReduction = {
type: "selection"
};
// Aggregates features to bins
layer.featureReduction = {
type: "binning",
renderer: {
type: "simple", // autocasts as new SimpleRenderer()
symbol: {
type: "simple-fill", // autocasts as new SimpleFillSymbol()
outline: { // autocasts as new SimpleLineSymbol()
width: 0.5,
color: "white"
}
},
visualVariables: [{
type: "color",
field: "aggregateCount",
stops: [
{ value: 1, color: "white" },
{ value: 1000, color: "blue" }
]
}]
},
popupTemplate: {
content: "This bin contains <b>{aggregateCount}</b> features.",
fieldInfos: [{
fieldName: "aggregateCount",
format: {
digitSeparator: true,
places: 0
}
}]
}
};

fields

autocast Property
Type
Field[]

An array of fields in the layer.

Example
// define each field's schema
let fields = [
new Field({
"name": "ObjectID",
"alias": "ObjectID",
"type": "oid"
}), new Field({
"name": "description",
"alias": "Description",
"type": "string"
}), new Field ({
"name": "title",
"alias": "Title",
"type": "string"
})
];

fieldsIndex

readonly Property
Type
FieldsIndex<Field>
Since
ArcGIS Maps SDK for JavaScript 4.12

A convenient property that can be used to make case-insensitive lookups for a field by name. It can also provide a list of the date fields in a layer.

Example
// lookup a field by name. name is case-insensitive
const field = layer.fieldsIndex.get("SoMeFiEld");
if (field) {
console.log(field.name); // SomeField
}

fullExtent

autocast Property
Type
Extent | null | undefined

The full extent of the layer.

Example
// Once the layer loads, set the view's extent to the layer's full extent
layer.when(function(){
view.extent = layer.fullExtent;
});

geometryType

Property
Type
"point" | "polygon" | "polyline" | "multipoint" | null | undefined

The geometry type of features in the layer. All features must be of the same type. The GeoJSONLayer can consume GeoJSON feature collections with mixed geometries and will only read the features with the specified geometry type if geometryType is set, otherwise the geometry type is determined from the first feature with a geometry. The geometry type is null if isTable is true.

hasZ

readonly Property
Type
boolean

Indicates whether the client-side features in the layer have Z (elevation) values. Refer to elevationInfo for details regarding placement and rendering of features with z-values in 3D SceneViews. Use the supportsZ property in the layer's capabilities.data object to verify if Z values are supported on the features.

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.

isTable

readonly Property
Type
boolean
Since
ArcGIS Maps SDK for JavaScript 4.24

Returns true if the layer is loaded from a non-spatial table in a service. Non-spatial geojson tables do not have geometry object that represent geographic features. The geometryType of the layer will be null if the isTable is true.

Non-spatial table instance can be created from the url and the table must be loaded by calling load() method.

See also
Default value
false

labelingInfo

autocast Property
Type
LabelClass[] | null | undefined

The label definition for this layer, specified as an array of LabelClass. Use this property to specify labeling properties for the layer such as label expression, placement, and size.

Multiple Label classes with different where clauses can be used to define several labels with varying styles on the same feature. Likewise, multiple label classes may be used to label different types of features (for example blue labels for lakes and green labels for parks).

Known Limitations

3D SceneViews only support displaying one LabelClass per feature.

See also
Example
const statesLabelClass = new LabelClass({
labelExpressionInfo: { expression: "$feature.NAME" },
symbol: {
type: "text", // autocasts as new TextSymbol()
color: "black",
haloSize: 1,
haloColor: "white"
}
});
geoJSONLayer.labelingInfo = [ statesLabelClass ];

labelsVisible

Property
Type
boolean

Indicates whether to display labels for this layer. If true, labels will appear as defined in the labelingInfo property.

Known Limitations

3D SceneViews only support displaying one LabelClass per feature.

Default value
true

legendEnabled

Property
Type
boolean

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.

ValueDescription
showThe layer is visible in the table of contents.
hideThe layer is hidden in the table of contents.
hide-childrenIf the layer is a GroupLayer, BuildingSceneLayer, KMLLayer, MapImageLayer, SubtypeGroupLayer, TileLayer, or WMSLayer, hide the children layers from the table of contents.
Default value
"show"

loaded

readonlyinherited Property
Type
boolean
Inherited from: Layer

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

Default value
false

loadError

readonlyinherited Property
Type
EsriError | null | undefined
Inherited from: LoadableMixin

The Error object returned if an error occurred while loading.

loadStatus

readonlyinherited Property
Type
"not-loaded" | "loading" | "failed" | "loaded"
Inherited from: LoadableMixin

Represents the status of a load() operation.

ValueDescription
not-loadedThe object's resources have not loaded.
loadingThe object's resources are currently loading.
loadedThe object's resources have loaded without errors.
failedThe 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;

objectIdField

Property
Type
string
Since
ArcGIS Maps SDK for JavaScript 4.15

The name of a field containing a unique value or identifier for each feature in the layer. if the feature id is present in the GeoJSON, it will be used as the oid field. Starting at version 4.22, this field will be a type of an oid field if the feature id is an integer, or will be a string field if the feature id is a string. If the feature id property is not present and objectIDField is not specified, __ObjectID field will be generated for each feature starting from 1.

See also

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.

Default value
1
Example
// Makes the layer 50% transparent
layer.opacity = 0.5;

orderBy

autocast inherited Property
Type
OrderByInfo[] | null | undefined
Inherited from: OrderedLayer
Since
ArcGIS Maps SDK for JavaScript 4.21

Determines the order in which features are drawn in the view. You can sort features by a field value or the value returned from an Arcade expression in ascending or descending order.

When null (default), features are drawn in the order they are returned from the service or client.

Known Limitations

  • This property only controls feature drawing order in MapView. Configuring feature drawing order in SceneView is not supported.
  • This property does not control the drawing order of clusters. It only applies to individual features.
  • Feature drawing order configurations defined with Arcade expressions cannot be saved to web maps.
  • Currently, you can only sort features by one field or expression.
See also
Examples
// Features with smaller population values will
// be rendered on top of larger features.
layer.orderBy = [{
field: "POPULATION"
}];
// Features with larger population values will
// be rendered on top of smaller features.
layer.orderBy = [{
field: "POPULATION",
order: "descending"
}];
// Orders features by date in descending order.
// The most recent features will be rendered
// on top of older features.
layer.orderBy = [{
field: "Alarm_Date",
order: "descending"
}];
// Orders features by storm warning duration in descending order.
// Warnings with longer durations
// be rendered on top of warnings with shorter durations.
layer.orderBy = [{
valueExpression: "DateDiff($feature.Watch_End, $feature.Watch_Start, 'hours' )",
order: "descending"
}];
// Orders features by data values used in a size visual variable
const sizeVariable = layer.renderer.visualVariables.find( vv => vv.type === "size");
const { field, valueExpression } = sizeVariable;
layer.orderBy = [{
field,
valueExpression,
order: "ascending"
}];

outFields

Property
Type
string[] | null | undefined
Since
ArcGIS Maps SDK for JavaScript 4.15

An array of field names from the geoJSON file to include with each feature. To fetch the values from all fields in the layer, use ["*"]. The required fields used for layer rendering, labeling, and setting the elevation info, along with the fields specified in outFields are used to populate FeatureLikeLayerView.availableFields. Set this property to include the fields that will be used for client-side queries if the fields are not part of required fields.

See also
Examples
// Includes all fields from the service in the layer
layer.outFields = ["*"];
// Get the specified fields from the service in the layer
// These fields will be added to FeatureLayerView.availableFields
// along with rendering and labeling fields. Use these fields
// for client-side filtering and querying.
layer.outFields = ["NAME", "POP_2010", "FIPS", "AREA"];

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

popupEnabled

Property
Type
boolean

Indicates whether to display popups when features in the layer are clicked. The layer needs to have a popupTemplate to define what information should be displayed in the popup. Alternatively, a default popup template may be automatically used if Popup.defaultPopupTemplateEnabled is set to true.

See also
Default value
true

popupTemplate

autocast Property
Type
PopupTemplate | null | undefined

The popup template for the layer. When set on the layer, the popupTemplate allows users to access attributes and display their values in the view's Popup when a feature is selected using text and/or charts. See the PopupTemplate sample for an example of how PopupTemplate interacts with a FeatureLayer.

A default popup template is automatically used if no popupTemplate has been defined when Popup.defaultPopupTemplateEnabled is set to true.

See also

portalItem

autocast Property
Type
PortalItem | null | undefined
Since
ArcGIS Maps SDK for JavaScript 4.25

The portal item referencing the geojson file from which the GeoJSONLayer is loaded.

Examples
// Initialize GeoJSONLayer by referencing a portalItem id pointing to geojson file.
const layer = new GeoJSONLayer({
portalItem: { // autocasts as new PortalItem()
id: "81e769cd7031482797e1b0768f23c7e1"
}
});
// 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/"
})
}
});
// 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"
}
});

refreshInterval

Property
Type
number
Since
ArcGIS Maps SDK for JavaScript 4.22

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

See also
Default value
0
Examples
// the layer will be refreshed every 1 minute.
layer.refreshInterval = 1;
// the layer will be refreshed every minute.
layer.refreshInterval = 1;

renderer

autocast Property
Type
RendererUnion | null | undefined

The renderer assigned to the layer. The renderer defines how to visualize each feature in the layer. Depending on the renderer type, features may be visualized with the same symbol, or with varying symbols based on the values of provided attribute fields or functions. If not specified, a default renderer will be generated based on the geometry type.

See also

screenSizePerspectiveEnabled

Property
Type
boolean

Apply perspective scaling to screen-size symbols in a SceneView. When true, screen sized objects such as icons, labels or callouts integrate better in the 3D scene by applying a certain perspective projection to the sizing of features. This only applies when using a SceneView.

layer.screenSizePerspectiveEnabled = true

screen-size-perspective

layer.screenSizePerspectiveEnabled = false

no-screen-size-perspective

Known Limitations

Screen size perspective is currently not optimized for situations where the camera is very near the ground, or for scenes with visual elements located far from the ground surface. In these cases it may be better to turn off screen size perspective. As screen size perspective changes the size based on distance to the camera, it should be set to false when using size visual variables.

Default value
true

spatialReference

autocast Property
Type
SpatialReference

The spatial reference of the layer. The default value is WGS84. This property can be set explicitly to project the longitude and latitude coordinates when the layer parses the GeoJSON file. While not required, explicitly setting the spatial reference of the layer will improve the performance when projecting to a spatial reference other than the one used by the coordinates in the raw data.

See also
Default value
SpatialReference.WGS84
Example
const geoJSONLayer = new GeoJSONLayer({
url: "example.geojson",
spatialReference: {
wkid: 5936
}
});

templates

autocast Property
Type
FeatureTemplate[] | null | undefined

An array of feature templates defined in the layer. See ArcGIS Pro subtypes document.

timeExtent

autocast Property
Type
TimeExtent | null | undefined
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)
}
});
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 Property
Type
TimeInfo | null | undefined

TimeInfo provides information such as date fields that store start and end time for each feature and the TimeInfo.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 GeoJSONLayer. The timeInfo parameters cannot be changed after the layer is loaded. The TimeInfo.fullTimeExtent for timeInfo is automatically calculated based on its startField and endField properties.

Examples
// 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.
// timeExtent is automatically calculated from the start and end date fields
// The date values must be in milliseconds number from the UNIX epoch specified in UTC.
timeInfo: {
startField: "time"
}
});
// 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 Property
Type
TimeInterval | null | undefined
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.

Examples
// Offset a geojson Layer containing hurricanes from 2015 so that they appear in 2019 (+4 years).
let layer = new GeoJSONLayer({
url: `hurricanes-and-storms-2015.geojson`,
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"
}
}
}
});
// 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.

Default value
"GeoJSON"

trackInfo

autocast inherited Property
Type
TrackInfo | null | undefined
Inherited from: TrackableLayer
Since
ArcGIS Maps SDK for JavaScript 4.32
beta

Allows you to render track data for a layer, including a track line, previous observations, and latest observations. For trackInfo to work, the layer must have timeInfo defined with a valid trackIdField.

type

readonly Property
Type
"geojson"

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 of the GeoJSON file.

Examples
// create geojson layer from USGS earthquakes data
const layer = new GeoJSONLayer({
url: "https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson"
});
// create a geojson layer from geojson feature collection
const geojson = {
type: "FeatureCollection",
features: [
{
type: "Feature",
id: 1,
geometry: {
type: "Polygon",
coordinates: [
[
[100.0, 0.0],
[101.0, 0.0],
[101.0, 1.0],
[100.0, 1.0],
[100.0, 0.0]
]
]
},
properties: {
prop0: "value0",
}
}
]
};
// create a new blob from geojson featurecollection
const blob = new Blob([JSON.stringify(geojson)], {
type: "application/json"
});
// URL reference to the blob
const url = URL.createObjectURL(blob);
// create new geojson layer using the blob url
const layer = new GeoJSONLayer({
url
});

useViewTime

Property
Type
boolean
Since
ArcGIS Maps SDK for JavaScript 4.14

Determines if the layer will update its temporal data based on the view's View.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.

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

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

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

MethodSignatureClass
fromArcGISServerUrl
inherited static
fromArcGISServerUrl(params: string | FromArcGISServerUrlParameters): Promise<Layer>
fromPortalItem
inherited static
fromPortalItem(params: LayerFromPortalItemParameters): Promise<Layer>
applyEdits(edits: Edits): Promise<EditsResult>
cancelLoad
inherited
cancelLoad(): this
createLayerView
inherited
createLayerView<T extends LayerView = LayerView>(view: View<T>, options?: AbortOptions): Promise<T>
createPopupTemplate(options?: CreatePopupTemplateOptions): PopupTemplate | null | undefined
createQuery(): Query
destroy
inherited
destroy(): void
emit
inherited
emit<Type extends EventNames<this>>(type: Type, event?: this["@eventTypes"][Type]): boolean
fetchAttributionData(): Promise<any>
getField(fieldName: string): Field | null | undefined
getFieldDomain(fieldName: string, options?: FieldDomainOptions): DomainUnion | null | undefined
hasEventListener
inherited
hasEventListener<Type extends EventNames<this>>(type: Type): boolean
isFulfilled
inherited
isFulfilled(): boolean
isRejected
inherited
isRejected(): boolean
isResolved
inherited
isResolved(): boolean
load
inherited
load(options?: AbortOptions | null | undefined): Promise<this>
on
inherited
on<Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle
queryAttributeBins(binsQuery: AttributeBinsQueryProperties, options?: RequestOptions): Promise<AttributeBinsFeatureSet>
queryExtent(query?: QueryProperties | null | undefined, options?: RequestOptions): Promise<{ count: number; extent: Extent | null; }>
queryFeatureCount(query?: QueryProperties | null | undefined, options?: RequestOptions): Promise<number>
queryFeatures(query?: QueryProperties | null | undefined, options?: RequestOptions): Promise<FeatureSet>
queryObjectIds(query?: QueryProperties | null | undefined, options?: RequestOptions): Promise<ObjectId[]>
refresh(): void
when
inherited
when<TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> | null | undefined, onRejected?: OnRejectedCallback<TResult2> | null | undefined): Promise<TResult1 | TResult2>

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.

URLReturns
Feature service with one layerFeatureLayer where FeatureLayer.isTable returns false.
Feature service with one tableFeatureLayer 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 LayersN/A
See also
Parameters
ParameterTypeDescriptionRequired
params

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 layerFeatureLayer where FeatureLayer.isTable returns false.
Feature service with one tableFeatureLayer where FeatureLayer.isTable returns true.
Feature service with more than one layer(s)/table(s)GroupLayer with layers and tables.
Feature collection with one layerFeatureLayer where FeatureLayer.isTable returns false.
Feature collection with one tableFeatureLayer where FeatureLayer.isTable returns true.
Feature collection with more than one layer(s)/table(s)GroupLayer with layers and tables.

Known Limitations

See also
Parameters
ParameterTypeDescriptionRequired
params

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);
}
});
});

applyEdits

Method
Signature
applyEdits (edits: Edits): Promise<EditsResult>

Applies edits to features in a layer. New features can be created and existing features can be updated or deleted on the client side. Feature geometries and/or attributes may be modified.

If client-side features are added, removed or updated at runtime using applyEdits() then use queryFeatures() to return updated features.

See also
Parameters
ParameterTypeDescriptionRequired
edits

Object containing features to be added, updated or deleted.

Returns
Promise<EditsResult>

Resolves to an object containing edit results. See the object specification table below for details.

PropertyTypeDescription
addFeatureResultsFeatureEditResult[]Result of adding features.
deleteFeatureResultsFeatureEditResult[]Result of deleting features.
updateFeatureResultsFeatureEditResult[]Result of updating features.
Example
function addFeature(geometry) {
const attributes = {};
attributes["Description"] = "This is the description";
attributes["Address"] = "380 New York St";
// Date.now() returns number of milliseconds elapsed
// since 1 January 1970 00:00:00 UTC.
attributes["Report_Date"] = Date.now();
const addFeature = new Graphic({
geometry: geometry,
attributes: attributes
});
const deleteFeature = {
objectId: [467]
};
const promise = geoJSONLayer.applyEdits({
addFeatures: [addFeature],
deleteFeatures: [deleteFeature]
});
}

cancelLoad

inherited Method
Signature
cancelLoad (): this
Inherited from: LoadableMixin

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

Returns
this

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
Parameters
ParameterTypeDescriptionRequired
view

The parent view.

options

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.

createPopupTemplate

Method
Signature
createPopupTemplate (options?: CreatePopupTemplateOptions): PopupTemplate | null | undefined

Creates a popup template for the layer, populated with all the fields of the layer.

Parameters
ParameterTypeDescriptionRequired
options

Options for creating the popup template.

Returns
PopupTemplate | null | undefined

The popup template, or null if the layer does not have any fields.

createQuery

Method
Signature
createQuery (): Query

Creates query parameter object that can be used to fetch features that satisfy the layer's configurations such as definitionExpression. It will return Z and M values based on the layer's data capabilities. It sets the query parameter's Query.outFields property to ["*"].

See also
Returns
Query

The query object representing the layer's definition expression and other configurations.

Example
// Get a query object for the layer's current configuration
// queryParams.outFields will be set to ["*"] to get values
// for all available fields.
const queryParams = layer.createQuery();
// set a geometry for filtering features by a region of interest
queryParams.geometry = extentForRegionOfInterest;
// Add to the layer's current definitionExpression
queryParams.where = queryParams.where + " AND TYPE = 'Extreme'";
// query the layer with the modified params object
layer.queryFeatures(queryParams).then(function(results){
// prints the array of result graphics to the console
console.log(results.features);
});

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

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

Parameters
ParameterTypeDescriptionRequired
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.

getField

Method
Signature
getField (fieldName: string): Field | null | undefined

Returns the Field instance for a field name (case-insensitive).

See also
Parameters
ParameterTypeDescriptionRequired
fieldName

Name of the field.

Returns
Field | null | undefined

the matching field or undefined

getFieldDomain

Method
Signature
getFieldDomain (fieldName: string, options?: FieldDomainOptions): DomainUnion | null | undefined

Returns the Domain associated with the given field name. The domain can be either a CodedValueDomain or RangeDomain.

Parameters
ParameterTypeDescriptionRequired
fieldName

Name of the field.

options

An object specifying additional options. See the object specification table below for the required properties of this object.

Returns
DomainUnion | null | undefined

The Domain object associated with the given field name for the given feature.

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
ParameterTypeDescriptionRequired
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
ParameterTypeDescriptionRequired
options

Additional options.

Returns
Promise<this>

Resolves when the resources have loaded.

on

inherited Method
Signature
on <Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle
Type parameters
<Type extends EventNames<this>>
Inherited from: EventedMixin

Registers an event handler on the instance. Call this method to hook an event with a listener.

Parameters
ParameterTypeDescriptionRequired
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).

PropertyTypeDescription
removeFunctionWhen 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);
});

queryAttributeBins

Method
Signature
queryAttributeBins (binsQuery: AttributeBinsQueryProperties, options?: RequestOptions): Promise<AttributeBinsFeatureSet>
Since
ArcGIS Maps SDK for JavaScript 4.33

Executes a AttributeBinsQuery against a GeoJSONLayer, which groups features into bins based on ranges in numeric or date fields, and returns a AttributeBinsFeatureSet containing the series of bins. Please refer to the AttributeBinsQuery document for more detailed information on how to configure the bin parameters.

Binned data can condense complex information into meaningful insight. This query allows you to classify data into meaningful categories and summarize the data within each bin with summary statistics. Binned data can be effectively visualized in histograms (or bar charts), providing clearer insights into data distributions and trends. It can reveal underlying patterns that might be obscured in raw data. For example, bins can show concentrations of values in common ranges.

Notes

The queryAttributeBins() method is unrelated to querying bins in FeatureReductionBinning.

See also
Parameters
ParameterTypeDescriptionRequired
binsQuery

Specifies the parameters of the queryAttributeBins() operation. The AttributeBinsQuery.binParameters property must be set.

options

An object with the following properties.

Returns
Promise<AttributeBinsFeatureSet>

When resolved, returns a AttributeBinsFeatureSet containing a series of bins. Each feature in the AttributeBinsFeatureSet represents a bin. The attributes of each feature contains statistics summarizing the data in the bin, including count, average, standard deviation, etc.

Example
// Query the temperature field in the feature layer and create a histogram
// Analyze temperature data over a year, create 100 bins for different temperature ranges
// to assess frequency and identify patterns.
const binQuery = new AttributeBinsQuery({
where: "UnitTop = 0",
binParameters: new AutoIntervalBinParameters({
bins: 100,
field: "temp",
start: 0, // lowest temp value to be included in the bin query
end: 30 // highest temp value to be included
})
});
layer.queryAttributeBins(query).then((results) => {
const bins = results.features.map((bin) => {
return {
minValue: bin.attributes.lowerBoundary,
maxValue: bin.attributes.upperBoundary,
count: bin.attributes.temperature_count,
};
});
// get the lower boundary of the first bin
const min = results.features[0].attributes.lowerBoundary;
// get the upper boundary of the last bin
const max = results.features[results.features.length - 1].attributes.upperBoundary;
// calculate the average for the bins
const average = results.features[0].attributes.lowerBoundary + results.features[results.features.length - 1].attributes.upperBoundary) / 2;
const histogram = new Histogram({
container: "histogramDiv",
bins: bins,
min: min,
max: max,
average: average,
barCreatedFunction:(index, element) => {
element.setAttribute("fill", "#FFA500");
element.setAttribute("opacity", 0.5);
},
labelFormatFunction: (value, type) => {
return (Math.round(value)).toLocaleString();
},
dataLines: [{
value: histogram.min,
label: histogram.min.toLocaleString()
}, {
value: histogram.average,
label: histogram.average.toLocaleString()
}, {
value: histogram.max,
label: histogram.max.toLocaleString()
}]
});
});

queryExtent

Method
Signature
queryExtent (query?: QueryProperties | null | undefined, options?: RequestOptions): Promise<{ count: number; extent: Extent | null; }>

Executes a Query against the layer and returns the Extent of features that satisfy the query. If no parameters are specified, then the extent and count of all features satisfying the layer's configuration/filters are returned.

Known Limitations

Spatial queries have the same limitations as those listed in the projectOperator documentation. Spatial queries are not currently supported if the layer view has any of the following SpatialReferences:

  • GDM 2000 (4742) – Malaysia
  • Gusterberg (Ferro) (8042) – Austria/Czech Republic
  • ISN2016 (8086) - Iceland
  • SVY21 (4757) - Singapore
Parameters
ParameterTypeDescriptionRequired
query

Specifies the attributes and spatial filter of the query. If no parameters are specified, then the extent and count of all features satisfying the layer's configuration/filters are returned.

options

An object with the following properties.

Returns
Promise<{ count: number; extent: Extent | null; }>

When resolved, returns the extent and count of the features that satisfy the input query. See the object specification table below for details.

PropertyTypeDescription
countNumberThe number of features that satisfy the input query.
extentExtent | nullThe extent of the features that satisfy the query.
Examples
// Queries for the extent of all features matching the layer's configurations
// e.g. definitionExpression
layer.queryExtent().then(function(results){
// go to the extent of the results satisfying the query
view.goTo(results.extent);
});
const layer = new GeoJSONLayer({
url: dataUrl
});
const query = new Query();
query.where = "region = 'Southern California'";
layer.queryExtent(query).then(function(results){
view.goTo(results.extent); // go to the extent of the results satisfying the query
});

queryFeatureCount

Method
Signature
queryFeatureCount (query?: QueryProperties | null | undefined, options?: RequestOptions): Promise<number>

Executes a Query against the layer and returns the number of features that satisfy the query. If no parameters are specified, the total number of features satisfying the layer's configuration/filters is returned.

Known Limitations

Spatial queries have the same limitations as those listed in the projectOperator documentation. Spatial queries are not currently supported if the layer view has any of the following SpatialReferences:

  • GDM 2000 (4742) – Malaysia
  • Gusterberg (Ferro) (8042) – Austria/Czech Republic
  • ISN2016 (8086) - Iceland
  • SVY21 (4757) - Singapore
Parameters
ParameterTypeDescriptionRequired
query

Specifies the attributes and spatial filter of the query. If no parameters are specified, the total number of features satisfying the layer's configuration/filters is returned.

options

An object with the following properties.

Returns
Promise<number>

When resolved, returns the number of features that satisfy the query.

Examples
// Queries for the count of all features matching the layer's configurations
// e.g. definitionExpression
layer.queryFeatureCount().then(function(numFeatures){
// prints the total count to the console
console.log(numFeatures);
});
const layer = new GeoJSONLayer({
url: dataUrl
});
const query = new Query();
query.where = "region = 'Southern California'";
layer.queryFeatureCount(query).then(function(numResults){
console.log(numResults); // prints the number of results satisfying the query
});

queryFeatures

Method
Signature
queryFeatures (query?: QueryProperties | null | undefined, options?: RequestOptions): Promise<FeatureSet>

Executes a Query against the layer and returns a FeatureSet once the promise resolves. A FeatureSet contains an array of Graphic features, which can be added to the view's graphics. This array will not be populated if zero results are found.

Known Limitations

Attribute values used in attribute queries executed against GeoJSONLayer are case sensitive. Spatial queries have the same limitations as those listed in the projectOperator documentation. Spatial queries are not currently supported if the layer view has any of the following SpatialReferences:

  • GDM 2000 (4742) – Malaysia
  • Gusterberg (Ferro) (8042) – Austria/Czech Republic
  • ISN2016 (8086) - Iceland
  • SVY21 (4757) - Singapore
See also
Parameters
ParameterTypeDescriptionRequired
query

Specifies the attributes and spatial filter of the query. If no parameters are specified, then all features satisfying the layer's configuration/filters are returned.

options

An object with the following properties.

Returns
Promise<FeatureSet>

When resolved, a FeatureSet containing an array of graphic features is returned.

Examples
// Queries for all the features matching the layer's configurations
// e.g. definitionExpression
layer.queryFeatures().then(function(results){
// prints the array of result graphics to the console
console.log(results.features);
});
const layer = new GeoJSONLayer({
url: geojsonUrl // points to a GeoJSON data url
});
const query = new Query();
query.where = "STATE_NAME = 'Washington'";
query.outSpatialReference = { wkid: 102100 };
query.returnGeometry = true;
query.outFields = [ "CITY_NAME" ];
layer.queryFeatures(query).then(function(results){
console.log(results.features); // prints the array of features to the console
});
// Get a query object for the layer's current configuration
const queryParams = layer.createQuery();
// set a geometry for filtering features by a region of interest
queryParams.geometry = extentForRegionOfInterest;
// Add to the layer's current definitionExpression
queryParams.where = queryParams.where + " AND TYPE = 'Extreme'";
// query the layer with the modified params object
layer.queryFeatures(queryParams).then(function(results){
// prints the array of result graphics to the console
console.log(results.features);
});

queryObjectIds

Method
Signature
queryObjectIds (query?: QueryProperties | null | undefined, options?: RequestOptions): Promise<ObjectId[]>

Executes a Query against the layer and returns an array of Object IDs for features that satisfy the input query. If no parameters are specified, then the Object IDs of all features satisfying the layer's configuration/filters are returned.

Known Limitations

Spatial queries have the same limitations as those listed in the projectOperator documentation. Spatial queries are not currently supported if the layer view has any of the following SpatialReferences:

  • GDM 2000 (4742) – Malaysia
  • Gusterberg (Ferro) (8042) – Austria/Czech Republic
  • ISN2016 (8086) - Iceland
  • SVY21 (4757) - Singapore
Parameters
ParameterTypeDescriptionRequired
query

Specifies the attributes and spatial filter of the query. If no parameters are specified, then the Object IDs of all features satisfying the layer's configuration/filters are returned.

options

An object with the following properties.

Returns
Promise<ObjectId[]>

When resolved, returns an array of numbers representing the object IDs of the features satisfying the query.

Examples
// Queries for all the Object IDs of features matching the layer's configurations
// e.g. definitionExpression
layer.queryObjectIds().then(function(results){
// prints the array of Object IDs to the console
console.log(results);
});
const layer = new GeoJSONLayer({
url: dataUrl
});
const query = new Query();
query.where = "region = 'Southern California'";
layer.queryObjectIds(query).then(function(ids){
console.log(ids); // an array of object IDs
});

refresh

Method
Signature
refresh (): void
Since
ArcGIS Maps SDK for JavaScript 4.22

Fetches all the data for the layer.

See also
Returns
void
Example
// update the customParameters for the query then call
// refresh method to fetch new features from the geojson
geojsonLayer.customParameters.limit = 10;
geojsonLayer.refresh();

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

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
ParameterTypeDescriptionRequired
onFulfilled

The function to call when the promise resolves.

onRejected

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

edits

inherited Event
Inherited from: EditBusLayerEvents

Fires after FeatureLayer.applyEdits() is completed successfully. The event payload includes only successful edits, not the failed edits. applyEdits() will pass in a sessionId during an active edit session.

See also
bubbles composed cancelable
Example
// This function will fire each time applyEdits() is completed successfully
layer.on("edits", function(event) {
const extractObjectId = function(result) {
return result.objectId;
};
const adds = event.addedFeatures.map(extractObjectId);
console.log("addedFeatures: ", adds.length, adds);
const updates = event.updatedFeatures.map(extractObjectId);
console.log("updatedFeatures: ", updates.length, updates);
const deletes = event.deletedFeatures.map(extractObjectId);
console.log("deletedFeatures: ", deletes.length, deletes);
});

layerview-create

inherited Event
Inherited from: LayerEvents

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

See also
bubbles composed cancelable
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
bubbles composed cancelable
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
Inherited from: LayerEvents

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

bubbles composed cancelable

refresh

inherited Event
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
bubbles composed cancelable
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