KnowledgeGraphSublayer

AMD: require(["esri/layers/knowledgeGraph/KnowledgeGraphSublayer"], (KnowledgeGraphSublayer) => { /* code goes here */ });
ESM: import KnowledgeGraphSublayer from "@arcgis/core/layers/knowledgeGraph/KnowledgeGraphSublayer.js";
Class: esri/layers/knowledgeGraph/KnowledgeGraphSublayer
Inheritance: KnowledgeGraphSublayerLayerAccessor
Since: ArcGIS Maps SDK for JavaScript 4.26
beta

A KnowledgeGraphSublayer is a sublayer of a KnowledgeGraphLayer or LinkChartLayer that contains all instances of a named type. For example, lets say a knowledge graph has Supplier, Part, and Manufacturer as entity types and buys_part and makes_part as relationship types.

When knowledge graph data is added to a map, each of the named types is a sublayer in the KnowledgeGraphLayer. Each sublayer contains all of the entity or relationship instances for that named type. Sublayers of spatial entity types contain features that will be added to the map or displayed in geographic layout on a link chart.

See also
Example
//to access individual sublayers in a KnowledgeGraphLayer
knowledgeGraphLayer.layers.items.forEach((sublayer)=>{
 sublayer.popupTemplate = new PopupTemplate({
  title: "{common_name}",
  content: [{
    type: "text",
    text: "Scientific Name: {name}"
  }]
 });
})

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.
Show inherited properties Hide inherited properties
Name Type Summary Class

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.

KnowledgeGraphSublayer

Describes the layer's supported capabilities.

KnowledgeGraphSublayer

The name of the class.

Accessor

The definition of the default popup template for the sublayer.

KnowledgeGraphSublayer

The SQL where clause used to filter features on the client.

KnowledgeGraphSublayer

The name of the sublayer's primary display field.

KnowledgeGraphSublayer

Effect provides various filter functions that can be performed on the layer to achieve different visual effects similar to how image filters work.

KnowledgeGraphSublayer

Specifies how features are placed on the vertical axis (z).

KnowledgeGraphSublayer

The featureEffect can be used to draw attention features of interest.

KnowledgeGraphSublayer

Configures the method for reducing the number of features in the view.

KnowledgeGraphSublayer

An array of fields in the layer.

KnowledgeGraphSublayer

A convenient property that can be used to make case-insensitive lookups for a field by name.

KnowledgeGraphSublayer

The full extent of the layer.

Layer

The name of the geometry field for the sublayer.

KnowledgeGraphSublayer

The geometry type of features in the sublayer.

KnowledgeGraphSublayer

Specifies whether the sublayer represents an entity type or relationship type.

KnowledgeGraphSublayer

Indicates whether the features in the sublayer have M (measurement) values.

KnowledgeGraphSublayer

Indicates whether the features in the layer have Z (elevation) values.

KnowledgeGraphSublayer

The unique ID assigned to the layer.

Layer

The label definition for this sublayer, specified as an array of label classes.

KnowledgeGraphSublayer

Indicates whether to display labels for this sublayer.

KnowledgeGraphSublayer

Indicates whether the layer will be included in the legend.

KnowledgeGraphSublayer

Indicates how the layer should display in the LayerList widget.

Layer

The Error object returned if an error occurred while loading.

Layer

Represents the status of a load operation.

Layer

A list of warnings which occurred while loading.

Layer

Indicates whether the layer's resources have loaded.

Layer

The maximum scale (most zoomed in) at which the layer is visible in the view.

KnowledgeGraphSublayer

The minimum scale (most zoomed out) at which the layer is visible in the view.

KnowledgeGraphSublayer

The name of an oid containing a unique value or identifier for each feature in the sublayer.

KnowledgeGraphSublayer

Outlines the type definition for the named type represented by the sublayer.

KnowledgeGraphSublayer

The opacity of the layer.

Layer

Determines the order in which features are drawn in the view.

KnowledgeGraphSublayer

The parent to which the layer belongs.

Layer

The KnowledgeGraphLayer of which this is a sublayer for a specific entity or relationship type.

KnowledgeGraphSublayer

When true, the layer can be persisted.

Layer

Enable persistence of the layer in a WebMap or WebScene.

persistenceEnabled

Indicates whether to display popups when features in the layer are clicked.

KnowledgeGraphSublayer

The popup template for the sublayer.

KnowledgeGraphSublayer

The renderer assigned to the sublayer.

KnowledgeGraphSublayer

The layer's time extent.

KnowledgeGraphSublayer

TimeInfo provides information such as date fields that store start and end time for each feature and the fullTimeExtent for the layer.

KnowledgeGraphSublayer

A temporary offset of the time data based on a certain TimeInterval.

KnowledgeGraphSublayer

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

Layer
For KnowledgeGraphSublayer the type is always "knowledge-graph-sublayer". KnowledgeGraphSublayer

Determines if the time enabled layer will update its temporal data based on the view's timeExtent.

KnowledgeGraphSublayer

Specifies a fixed time extent during which a layer should be visible.

Layer

Indicates if the layer is visible in the View.

Layer

Property Details

blendMode

Property
blendMode 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. 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.
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
no-blendmode overlay-blend
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.

color-blend
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).

destination-in
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.

color-blend
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.

Possible Values:"average" |"color-burn" |"color-dodge" |"color" |"darken" |"destination-atop" |"destination-in" |"destination-out" |"destination-over" |"difference" |"exclusion" |"hard-light" |"hue" |"invert" |"lighten" |"lighter" |"luminosity" |"minus" |"multiply" |"normal" |"overlay" |"plus" |"reflect" |"saturation" |"screen" |"soft-light" |"source-atop" |"source-in" |"source-out" |"vivid-light" |"xor"

Default Value:"normal"
See also

capabilities

Property
capabilities Capabilitiesreadonly

Describes the layer's supported capabilities.

Example
// Once the layer loads, check if the
// supportsAdd operations is enabled on the layer
featureLayer.when(function(){
  if (featureLayer.capabilities.operations.supportsAdd) {
    // if new features can be created in the layer
    // set up the UI for editing
    setupEditing();
  }
});

declaredClass

Inherited
Property
declaredClass Stringreadonly
Inherited from Accessor

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

defaultPopupTemplate

Property
defaultPopupTemplate PopupTemplatereadonly

The definition of the default popup template for the sublayer.

definitionExpression

Property
definitionExpression String

The SQL where clause used to filter features on the client. Only the features that satisfy the definition expression are displayed in the View. A definition expression is different from an inclusion list because it is applied after the parent KnowledgeGraphLayer is returned. Setting a definition expression is useful when the dataset is large and you don't want to bring all features to the client for analysis.

Example
// Set the definition expression directly on sublayer instance to only suppliers with more than 50 employees.
knowledgeGraphLayer.layers.items[0].definitionExpression = "employee_count > 50";

displayField

Property
displayField String

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

effect

Property
effect Effect |null |undefinedautocast

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.
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

Property
elevationInfo Object

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.

Known Limitations

  • KnowledgeGraphServices do not currently support Z-values.
  • If the elevation info is not specified, the effective elevation depends on the context and could vary per graphic.
Properties
mode String

Defines how the feature is placed with respect to the terrain surface or 3D objects in the scene. If the geometry consists of multiple points (e.g. lines or polygons), the elevation is evaluated separately for each point. See the table below for a list of possible values.

elevation-info

Mode Description
on-the-ground Features are aligned to the Ground. If the scene contains an IntegratedMeshLayer or IntegratedMesh3DTilesLayer, then features are aligned to the IntegratedMeshLayer or IntegratedMesh3DTilesLayer. If features have z-values, then the z-values are ignored in this mode. Features with 2D symbols are draped on the Ground or IntegratedMeshLayer or IntegratedMesh3DTilesLayer. This is the default mode for layers without z-values containing Polyline, Polygon features or Point features rendered with ObjectSymbol3DLayer.
absolute-height Features are placed at an absolute elevation (z-value) above sea level. This z-value is determined by the geometry's z-value (if present). If featureExpressionInfo is defined, the result of the expression is used instead of the geometry’s z-value. This mode doesn't take the elevation of the Ground or any other layers into account. This is the default value of features with any geometry type where hasZ is true.
relative-to-ground Features are placed at an elevation relative to the Ground or IntegratedMeshLayer or IntegratedMesh3DTilesLayer. The feature's elevation is determined by summing up the elevation of the Ground or IntegratedMeshLayer or IntegratedMesh3DTilesLayer and the geometry's z-value (if present). If featureExpressionInfo is defined, the result of the expression is used instead of the geometry’s z-value. If the geometries don't have z-values, relative-to-ground is the default value for Point geometries rendered with IconSymbol3DLayers.
relative-to-scene Features are aligned to extruded polygons, meshes, 3D Object SceneLayers or BuildingSceneLayers, depending on which one has higher elevation. If the feature is not directly above a building or any other feature, it is aligned to the elevation of the Ground or the IntegratedMeshLayer or IntegratedMesh3DTilesLayer. If present, the geometry's z-value is added to the elevation. If featureExpressionInfo is defined, the result of the expression is used instead of the geometry’s z-value.

Possible Values:"on-the-ground"|"relative-to-ground"|"absolute-height"|"relative-to-scene"

offset Number|null
optional

An elevation offset, which is added to the vertical position of the feature. If unit is not defined, the offset is in meters. When mode = "on-the-ground", this property has no effect.

featureExpressionInfo Object
optional

Defines how to override a feature's Z-value based on its attributes.

Specification
title String
optional

Title of the expression.

expression String
optional

An Arcade expression following the specification defined by the Arcade Feature Z Profile. Expressions may reference field values using the $feature profile variable and must return a number representing the z-value of the feature. When mode = "on-the-ground", this property has no effect. For line and polygon geometries the result of the expression is the same for all vertices of a feature.

optional

The unit for featureExpressionInfo and offset values.

See also

featureEffect

Property
featureEffect FeatureEffect |null |undefinedautocast

The featureEffect can be used to draw attention 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

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%)"
});

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.
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

Property
fields Field[]autocast
Autocasts from Object[]

An array of fields in the layer. Each field represents an attribute that may contain a value for each feature in the layer.

Example
// define each field's schema
const 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

Property
fieldsIndex FieldsIndex |null |undefinedreadonly

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

Inherited
Property
fullExtent Extent |null |undefinedautocast
Inherited from Layer

The full extent of the layer. By default, this is worldwide. This property may be used to set the extent of the view to match a layer's extent so that its features appear to fill the view. See the sample snippet below.

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

geometryFieldName

Property
geometryFieldName String

The name of the geometry field for the sublayer.

geometryType

Property
geometryType String

The geometry type of features in the sublayer.

Possible Values:"point" |"multipoint" |"polyline" |"polygon"

graphType

Property
graphType String

Specifies whether the sublayer represents an entity type or relationship type.

Possible Values:"entity" |"relationship"

hasM

Property
hasM Boolean

Indicates whether the features in the sublayer have M (measurement) values. Use the supportsM property in the KnowledgeGraphSublayer's capabilities.data object to verify if M values are supported.

Default Value:false

hasZ

Property
hasZ Boolean

Indicates whether the 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 KnowledgeGraphSublayer's capabilities.data object to verify if Z values are supported.

Known Limitations

KnowledgeGraphService's do not currently support Z-values.

Default Value:false

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.

labelingInfo

Property
labelingInfo LabelClass[] |null |undefinedautocast
Autocasts from Object[]

The label definition for this sublayer, specified as an array of label classes. Use this property to specify labeling properties for the sublayer 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).

See the Labeling guide page for more information and known limitations.

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

knowledgeGraphLayer.layers.items[0].labelingInfo = [ statesLabelClass ];

labelsVisible

Property
labelsVisible Boolean

Indicates whether to display labels for this sublayer. 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
legendEnabled Boolean

Indicates whether the layer will be included in the legend. When false, the layer will be excluded from 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"

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.

loaded

Inherited
Property
loaded Booleanreadonly
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

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

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

objectIdField

Property
objectIdField String

The name of an oid containing a unique value or identifier for each feature in the sublayer.

objectType

Property
objectType GraphObjectType

Outlines the type definition for the named type represented by the sublayer.

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;

orderBy

Property
orderBy Accessor[] |null |undefinedautocast

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 webmaps.
  • Currently, you can only sort features by one field or expression.
Properties
field String|null
optional

The number or date field whose values will be used to sort features.

valueExpression String|null
optional

An Arcade expression following the specification defined by the Arcade Feature Z Profile. Expressions may reference field values using the $feature profile variable and must return a number or a date representing the z-value used to sort features.

order String
optional
Default Value:ascending

The sort order. If ascending, then features with smaller data values (they usually have smaller symbols in size visualizations) will be drawn on top of features with larger data values. If descending, then features with larger data values (usually larger symbols in size visualizations) will be drawn on top of features with smaller data values. If date values are used, then ascending means features with older values will be drawn on top of features with more recent dates. A descending order for dates indicates features with more recent values will be drawn on top of features with older values.

Possible Values:"ascending"|"descending"

Default Value:null
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"
}];

parent

Inherited
Property
parent Map |Basemap |Ground |GroupLayer |CatalogDynamicGroupLayer |CatalogLayer
Inherited from Layer
Since: ArcGIS Maps SDK for JavaScript 4.27 Layer since 4.0, parent added at 4.27.

The parent to which the layer belongs.

parentCompositeLayer

Property
parentCompositeLayer KnowledgeGraphLayer

The KnowledgeGraphLayer of which this is a sublayer for a specific entity or relationship type.

persistenceEnabled

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

When true, the layer can be persisted. This property only has an effect for layers that are part of the WebMap or WebScene spec.

Default Value:false

persistenceEnabled

Property
persistenceEnabled Booleaninner,readonly

Enable persistence of the layer in a WebMap or WebScene.

Default Value:true

popupEnabled

Property
popupEnabled 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.

Default Value:true
See also

popupTemplate

Property
popupTemplate PopupTemplateautocast

The popup template for the sublayer. When set on the sublayer, 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. .

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

renderer

Property
renderer Rendererautocast

The renderer assigned to the sublayer. The renderer defines how to visualize each feature in the sublayer. 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.

Example
// all features in the sublayer will be visualized with
// a 6pt black marker symbol and a thin, white outline

//Apply renderer to the first sublayer of the KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];
sublayer.renderer = {
  type: "simple",  // autocasts as new SimpleRenderer()
  symbol: {
    type: "simple-marker",  // autocasts as new SimpleMarkerSymbol()
    size: 6,
    color: "black",
    outline: {  // autocasts as new SimpleLineSymbol()
      width: 0.5,
      color: "white"
    }
  }
};

timeExtent

Property
timeExtent TimeExtent |null |undefinedautocast

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

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

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

Inherited
Property
title String |null |undefined
Inherited from Layer

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

If the layer is loaded from a portal item, the title of the portal item will be used. 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 KnowledgeGraphSublayer the type is always "knowledge-graph-sublayer".

useViewTime

Property
useViewTime Boolean

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);
}

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.

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;

// 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;
    }
  }
);

Method Overview

Show inherited methods Hide inherited methods
Name 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
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

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

KnowledgeGraphSublayer

Creates query parameter object that can be used to fetch features that satisfy the layer's configurations such as definitionExpression,.

KnowledgeGraphSublayer

Destroys the layer and any associated resources (including its portalItem, if it is a property on the layer).

Layer

Emits an event on the instance.

Layer
Promise<Object>

Fetches custom attribution data for the layer when it becomes available.

Layer

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

KnowledgeGraphSublayer

Returns the Domain associated with the given field name.

KnowledgeGraphSublayer

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

Layer

Returns true if a named group of handles exist.

Accessor

isFulfilled() may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected).

Layer

isRejected() may be used to verify if creating an instance of the class is rejected.

Layer

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

Registers an event handler on the instance.

Layer
Promise<Object>

Executes a Query against the knowledge graph service and returns the Extent of features that satisfy the query.

KnowledgeGraphSublayer
Promise<Number>

Executes a Query against the knowledge graph service and returns the number of features that satisfy the query.

KnowledgeGraphSublayer
Promise<FeatureSet>

Executes a Query against the feature service and returns a FeatureSet, which can be accessed using the .then() method once the promise resolves.

KnowledgeGraphSublayer
Promise<Number[]>

Executes a Query against the knowledge graph service and returns an array of Object IDs for features that satisfy the input query.

KnowledgeGraphSublayer

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

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.

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.

createPopupTemplate

Method
createPopupTemplate(options){PopupTemplate}

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

Starting with version 4.28, date fields are formatted using the short-date-short-time preset dateFormat rather than long-month-day-year in popup templates created with the createPopupTemplate() method. For example, previously a date that may have appeared as "December 30, 1997" will now appear as "12/30/1997 6:00 PM".

Parameter
optional

Options for creating the popup template.

Returns
Type Description
PopupTemplate The popup template, or null if the layer does not have any fields.

createQuery

Method
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 outFields property to ["*"]. The results will include geometries of features and values for all available fields for client-side queries or all fields in the layer for server side queries.

Returns
Type Description
Query The query object representing the sublayer'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.

//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];
const queryParams = sublayer.createQuery();
// set a geometry for filtering features by a region of interest
queryParams.geometry = extentForRegionOfInterest;
// Add to the sublayer's current definitionExpression
queryParams.where = queryParams.where + " AND TYPE = 'Extreme'";

// query the sublayer with the modified params object
sublayer.queryFeatures(queryParams).then(function(results){
  // prints the array of result graphics to the console
  console.log(results.features);
});

destroy

Inherited
Method
destroy()
Inherited from Layer

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.

emit

Inherited
Method
emit(type, event){Boolean}
Inherited from Layer

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.

getField

Method
getField(fieldName){Field}

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

Parameter
fieldName String

Name of the field.

Returns
Type Description
Field the matching field or undefined

getFieldDomain

Method
getFieldDomain(fieldName, options){Domain}

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

Parameters
fieldName String

Name of the field.

options Object
optional

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

Specification
feature Graphic

The feature to which the Domain is assigned.

Returns
Type Description
Domain The Domain object associated with the given field name for the given feature.
Example
// Get a range domain associated with the first feature
// returned from queryFeatures().
//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];
sublayer.queryFeatures(query).then(function(results){
  const domain = sublayer.getFieldDomain("Height", {feature: results.features[0]});
  console.log("domain", domain)
});

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

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.

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

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);
});

queryExtent

Method
queryExtent(query, options){Promise<Object>}

Executes a Query against the knowledge graph service 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 sublayer's configuration/filters are returned.

Parameters
query Query autocast
optional
Autocasts from Object

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

options Object
optional

An object with the following properties.

Specification
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<Object> When resolved, returns the extent and count of the features that satisfy the input query. See the object specification table below for details.
Property Type Description
count Number The number of features that satisfy the input query.
extent Extent The extent of the features that satisfy the query.
Examples
// Queries for the extent of all features matching the layer's configurations
// e.g. definitionExpression
//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];
sublayer.queryExtent().then(function(results){
  // go to the extent of the results satisfying the query
  view.goTo(results.extent);
});
//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];

const query = new Query();
query.where = "region = 'Southern California'";

sublayer.queryExtent(query).then(function(results){
  view.goTo(results.extent);  // go to the extent of the results satisfying the query
});

queryFeatureCount

Method
queryFeatureCount(query, options){Promise<Number>}

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

Parameters
query Query autocast
optional
Autocasts from Object

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 Object
optional

An object with the following properties.

Specification
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<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
//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];
sublayer.queryFeatureCount().then(function(numFeatures){
  // prints the total count to the console
  console.log(numFeatures);
});
//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];

const query = new Query();
query.where = "region = 'Southern California'";

sublayer.queryFeatureCount(query).then(function(numResults){
  console.log(numResults);  // prints the number of results satisfying the query
});

queryFeatures

Method
queryFeatures(query, options){Promise<FeatureSet>}

Executes a Query against the feature service and returns a FeatureSet, which can be accessed using the .then() method once the promise resolves. A FeatureSet contains an array of Graphic features. See the querying section for more information on how to query features from a layer.

To query features/graphics available to or visible in the View on the client rather than making a server-side query, you must use the FeatureLayerView.queryFeatures() method.

When querying a service with z-values and no vertical coordinate system information, the z-values will automatically be converted to match the outSpatialReference units. Example: The service has a horizontal spatial reference using feet units and the query is made with outSpatialReference based on meter units, then queryFeatures() automatically converts the values from feet to meter units.

Parameters
query Query autocast
optional
Autocasts from Object

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 Object
optional

An object with the following properties.

Specification
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<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
 //get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];
sublayer.queryFeatures().then(function(results){
  // prints the array of result graphics to the console
  console.log(results.features);
});
//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];

const query = new Query();
query.where = "STATE_NAME = 'Washington'";
query.outSpatialReference = { wkid: 102100 };
query.returnGeometry = true;
query.outFields = [ "CITY_NAME" ];

sublayer.queryFeatures(query).then(function(results){
  console.log(results.features);  // prints the array of features to the console
});
// Get a query object for the sublayer's current configuration
const queryParams = sublayer.createQuery();
// set a geometry for filtering features by a region of interest
queryParams.geometry = extentForRegionOfInterest;
// Add to the sublayer's current definitionExpression
queryParams.where = queryParams.where + " AND TYPE = 'Extreme'";

// query the sublayer with the modified params object
sublayer.queryFeatures(queryParams).then(function(results){
  // prints the array of result graphics to the console
  console.log(results.features);
});
//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];

// query all features from the layer and only return
// attributes specified in outFields.
const query = { // autocasts as Query
  where: "1=1", // select all features
  returnGeometry: false,
  outFields: ["State_Name", "City_Name", "pop2010"]
};

sublayer.queryFeatures(query).then(function(results){
  console.log(results.features);  // prints the array of features to the console
});

queryObjectIds

Method
queryObjectIds(query, options){Promise<Number[]>}

Executes a Query against the knowledge graph service 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.

Parameters
query Query autocast
optional
Autocasts from Object

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

options Object
optional

An object with the following properties.

Specification
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<Number[]> 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
//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = knowledgeGraphLayer.layers.items[0];
sublayer.queryObjectIds().then(function(results){
  // prints the array of Object IDs to the console
  console.log(results);
});
//get the first sublayer from the parent KnowledgeGraphLayer
const sublayer = linkChartLayer.layers.items[0];

const query = new Query();
query.where = "region = 'Southern California'";

sublayer.queryObjectIds(query).then(function(ids){
  console.log(ids);  // an array of object IDs
});

removeHandles

Inherited
Method
removeHandles(groupKey)
Inherited from Accessor

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

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

Parameters
callback Function
optional

The function to call when the promise resolves.

errback Function
optional

The function to execute when the promise fails.

Returns
Type Description
Promise Returns a new promise for the result of callback that may be used to chain additional functions.
Example
// Although this example uses MapView, any class instance that is a promise may use when() in the same way
let view = new MapView();
view.when(function(){
  // This function will execute once the promise is resolved
}, function(error){
  // This function will execute if the promise is rejected due to an error
});

Type Definitions

Capabilities

Type Definition
Capabilities Object

Describes the layer's supported capabilities.

Properties
analytics Object

Describes what analytics capabilities are enabled on the layer.

Specification
supportsCacheHint Boolean

Indicates if the feature service supports cache hint.

attachment Object|null|undefined

Describes what attachment capabilities are enabled on the layer.

Specification
supportsCacheHint Boolean

Indicates if the attachment operations support a cache hint. This is valid only for hosted feature services.

supportsContentType Boolean

Indicates if the attachments can be queried by their content types.

supportsExifInfo Boolean

Indicates if the attachment queries support exifInfo.

supportsKeywords Boolean

Indicates if the attachments can be queried by their keywords.

supportsName Boolean

Indicates if the attachments can be queried by their names.

supportsSize Boolean

Indicates if the attachments can be queried by their sizes.

supportsResize Boolean

Indicates if resized attachments are supported in the feature layer. This is useful for showing thumbnails in Popups.

data Object

Describes characteristics of the data in the layer.

Specification
isVersioned Boolean

Indicates if the feature service is versioned.

supportsAttachment Boolean

Indicates if the attachment is enabled on the layer.

supportsM Boolean

Indicates if the features in the layer support m-values.

supportsZ Boolean

Indicates if the features in the layer support z-values. See elevationInfo for details regarding placement and rendering of features with z-values in 3D SceneViews.

editing Object

Describes editing capabilities that can be performed on the features in the layer.

Specification
supportsDeleteByAnonymous Boolean

Indicates if anonymous users can delete features created by others.

supportsDeleteByOthers Boolean

Indicates if logged in users can delete features created by others.

supportsGeometryUpdate Boolean

Indicates if the geometry of the features in the layer can be edited.

supportsGlobalId Boolean

Indicates if the globalId values provided by the client are used in editing.

supportsRollbackOnFailure Boolean

Indicates if the rollbackOnFailureEnabled parameter can be set to true or false when editing features.

supportsUpdateByAnonymous Boolean

Indicates if anonymous users can update features created by others.

supportsUpdateByOthers Boolean

Indicates if logged in users can update features created by others.

supportsUploadWithItemId Boolean

Indicates if the layer supports uploading attachments by UploadId.

supportsUpdateWithoutM Boolean

Indicates if m-values must be provided when updating features.

metadata Object

Describes the metadata contained on features in the layer.

Specification
supportsAdvancedFieldProperties Boolean

Indicates whether to provide a user-defined field description. See Describe attribute fields for additional information.

operations Object

Describes operations that can be performed on features in the layer.

Specification
supportsAdd Boolean

Indicates if new features can be added to the layer.

supportsCalculate Boolean

Indicates if values of one or more field values in the layer can be updated. See the Calculate REST operation document for more information.

supportsDelete Boolean

Indicates if features can be deleted from the layer.

supportsEditing Boolean

Indicates if features in the layer can be edited. Use supportsAdd, supportsUpdate and supportsDelete to determine which editing operations are supported.

supportsQuery Boolean

Indicates if features in the layer can be queried.

supportsQueryAttachments Boolean

Indicates if the layer supports REST API queryAttachments operation. If false, queryAttachments() method can only return attachments for one feature at a time. If true, queryAttachments() can return attachments for array of objectIds.

supportsResizeAttachments Boolean

Deprecated since 4.24. Use attachment.supportsResize instead. Indicates if resized attachments are supported in the feature layer. This is useful for showing thumbnails in Popups.

supportsQueryTopFeatures Boolean

Indicates if the layer supports REST API queryTopFeatures operation.

supportsUpdate Boolean

Indicates if features in the layer can be updated.

supportsValidateSql Boolean

Indicates if the layer supports a SQL-92 expression or where clause.

query Object

Describes query operations that can be performed on features in the layer.

Properties
maxRecordCount Number
optional

The maximum number of records that will be returned for a given query.

supportsCacheHint Boolean

Indicates if the query operation supports a cache hint. This is valid only for hosted feature services.

supportsCentroid Boolean

Indicates if the geometry centroid associated with each polygon feature can be returned.

supportsDisjointSpatialRelationship Boolean

Indicates if the query operation supports disjoint spatial relationship. This is valid only for hosted feature services.

supportsDistance Boolean

Indicates if the layer's query operation supports a buffer distance for input geometries.

supportsDistinct Boolean

Indicates if the layer supports queries for distinct values based on fields specified in the outFields.

supportsExtent Boolean

Indicates if the layer's query response includes the extent of features.

supportsGeometryProperties Boolean

Indicates if the layer's query response contains geometry attributes, including shape area and length attributes.

supportsHavingClause Boolean

Indicates if the layer supports the having clause on the service.

supportsHistoricMoment Boolean

Indicates if the layer supports historic moment query.

supportsOrderBy Boolean

Indicates if features returned in the query response can be ordered by one or more fields.

supportsPagination Boolean

Indicates if the query response supports pagination.

supportsPercentileStatistics Boolean

Indicates if the layer supports percentile statisticType.

supportsQuantization Boolean

Indicates if the query operation supports the projection of geometries onto a virtual grid.

supportsQuantizationEditMode Boolean

Indicates if the query operation supports quantization designed to be used in edit mode (highest resolution at the given spatial reference).

supportsQueryGeometry Boolean

Indicates if the query response includes the query geometry.

supportsResultType Boolean

Indicates if the number of features returned by the query operation can be controlled.

supportsStandardizedQueriesOnly Boolean

Indicates if the layer supports using standardized queries. Learn more about standardized queries here.

supportsStatistics Boolean

Indicates if the layer supports field-based statistical functions.

supportsSqlExpression Boolean

Indicates if the layer supports SQL expressions.

supportsSpatialAggregationStatistics Boolean

Indicates if the layer supports spatial extent, center or convex hull to be returned for each distinct group when groupByFieldsForStatistics is used. Supported with ArcGIS Online hosted features services only.

supportedSpatialAggregationStatistics Object

List of supported aggregated geometries returned for each distinct group when groupByFieldsForStatistics is used.

Specification
centroid Boolean

Indicates if the layer can return centroid for each distinct group for groupByFieldsForStatistics.

envelope Boolean

Indicates if the layer can return extent for each distinct group for groupByFieldsForStatistics.

convexHull Boolean

Indicates if the layer can return convex hull for each distinct group for groupByFieldsForStatistics.

queryRelated Object

Indicates if the layer's query operation supports querying features or records related to features in the layer.

Specification
supportsCacheHint Boolean

Indicates if the relationship query operation supports a cache hint. This is valid only for hosted feature services.

supportsCount Boolean

Indicates if the layer's query response includes the number of features or records related to features in the layer.

supportsOrderBy Boolean

Indicates if the related features or records returned in the query response can be ordered by one or more fields.

supportsPagination Boolean

Indicates if the query response supports pagination for related features or records.

queryTopFeatures Object

Describes top features query operations that can be performed on features in the layer.

Specification
supportsCacheHint Boolean

Indicates if the top query operation supports a cache hint. This is valid only for hosted feature services.

Event Overview

Show inherited events Hide inherited events
Name 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

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
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
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.

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