KnowledgeGraphLayer

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

A KnowledgeGraphLayer is a composite layer that can be created from a knowledge graph service. The layer contains feature sublayers for each spatial entity type. The layer contains table sublayers for each non-spatial entity type and relationship type contained in the KnowledgeGraphLayer.

Spatial entity and relationship types have geometries that allows them to be rendered in a MapView as a graphic with spatial context. Spatial types also contain data attributes that provide additional information about the real-world feature it represents; attributes may be viewed in popup windows and used for rendering the layer. Spatial type sublayers may be queried, analyzed, and rendered to visualize data in a spatial context.

Non-spatial sublayers are tables which do not have a spatial column representing geographic features. These sublayers also contain attributes and can be queried.

Known Limitations

A knowledgeGraphLayer can be added to an instance of a Map but it cannot be saved as an ArcGIS Enterprise portal item or added to an ArcGIS WebMap or ArcGIS MapViewer.

KnowledgeGraphLayer can only be used with KnowledgeGraphServices on ArcGIS Enterprise 11.1 or later.

Create Knowledge Graph Layer

To create a KnowledgeGraphLayer from knowledgeGraphService, you must set the url property to the REST endpoint of the service. For a layer to be visible in a view, it must be added to the Map referenced by the view. See Map.add() for information about adding layers to a map.

require(["esri/layers/KnowledgeGraphLayer"], function(KnowledgeGraphLayer){
  const kgl = new KnowledgeGraphLayer({
    url: "https://sampleserver7.arcgisonline.com/arcgis/rest/services/Hosted/SupplyChain/KnowledgeGraphServer"
  });
  kgl.load().then(()=>{
    map.add(kgl);  // adds the layer to the map
  })
});

Querying

Both spatial and non-spatial sublayers can be queried using the sublayer.queryFeatures() method. A query cannot be applied to the entire KnowledgeGraphLayer. Instead it must be applied to the individual sublayers.

//iterate through spatial sublayers and query each
kgLayer.layers.items.forEach((sublayer)=>{
  sublayer.queryFeatures("WHERE name = 'Supplier 5'").then((results)=>{
    console.log(results)
  })
})

Data Visualization

Features in the spatial sublayers of a KnowledgeGraphLayer are visualized by setting a Renderer to the renderer property of the sublayer. Features may be visualized with the same symbol using SimpleRenderer, by type with UniqueValueRenderer, with class breaks using ClassBreaksRenderer, or with continuous color, size, or opacity schemes using visual variables in any of the renderers. Symbols can only be set through a renderer and not individually on each graphic in the layer. See the documentation for Renderer and the Creating visualizations manually guide for more information about the various visualization options.

//create new KnowledgeGraphLayer
const kgLayer = new KnowledgeGraphLayer({
  url: "https://sampleserver7.arcgisonline.com/arcgis/rest/services/Hosted/SupplyChain/KnowledgeGraphServer"
});

//define renderer for all observations
const observationRenderer = {
  type: "simple", // autocasts as new SimpleRenderer()
  symbol: {
    type: "simple-marker",
    size: 6,
    color: "yellow",
    outline: {  // autocasts as new SimpleLineSymbol()
      width: 0.5,
      color: "white"
    }
  }
};

//define renderer for all users
const userRenderer = {
  type: "simple", // autocasts as new SimpleRenderer()
  symbol: {
    type: "simple-marker",
    size: 6,
    color: "purple",
    outline: {  // autocasts as new SimpleLineSymbol()
      width: 0.5,
      color: "white"
    }
  }
};

//define unique value renderer for 'species' type based on the 'common_name' field
const speciesRenderer = {
  type: "unique-value", // autocasts as new UniqueValueRenderer()
  field: "common_name",
  defaultSymbol: { type: "simple-fill" },  // autocasts as new SimpleFillSymbol()
  uniqueValueInfos: [{
    // All features with value of "Yellow-banded Bumble Bee" will be blue
    value: "Yellow-banded Bumble Bee",
    symbol: {
      type: "simple-fill",  // autocasts as new SimpleFillSymbol()
      color: "blue",
      size: 8
    }
  }, {
    // All features with value of "Two-spotted Bumble Bee" will be green
    value: "Two-spotted Bumble Bee",
    symbol: {
      type: "simple-fill",  // autocasts as new SimpleFillSymbol()
      color: "green",
      size: 6
    }
  }, {
    // All features with value of "Buff-tailed Bumble Bee" will be red
    value: "Buff-tailed Bumble Bee",
    symbol: {
      type: "simple-fill",  // autocasts as new SimpleFillSymbol()
      color: "orange",
      size: 4
    }
  }]
};

//when layer loads, apply renderers to sublayers
kgLayer.load().then(()=>{
  kgLayer.layers.items.forEach((sublayer)=> {
    switch(sublayer.title) {
      case 'Observation':
        sublayer.renderer = observationRenderer;
        break;
      case 'User':
        sublayer.renderer = userRenderer;
        break;
      case 'Species':
        sublayer.renderer = speciesRenderer;
        break;
      default:
       sublayer.renderer =  {
          type: "simple", // autocasts as new SimpleRenderer()
          symbol: {
            type: "simple-marker",
            size: 6,
            color: "white",
          }
        }
        break;
    }
  })
  map.add(kgLayer);
});

Labels can also be set for each sublayer.

kgLayer.load().then(()=>{
  kgLayer.layers.items.forEach((sublayer)=> {
    //label all points by their type.
    sublayer.labelingInfo = [
      new LabelClass({
        labelExpression: `${sublayer.objectType.name}`,
        symbol: {
          type: "text", // autocasts as new TextSymbol()
          color: [255, 255, 255, 0.7],
          haloColor: [0, 0, 0, 0.85],
          haloSize: 1,
          font: {
            size: 11
          }
        }
      })
    ];
    sublayer.labelsVisible = true;
  })
})

Popups can be set on each sublayer.

//create popup template for observations
const observationPopup = new PopupTemplate({
  title: "{species_guess}",
  content: [{
    type: "text",
    text: "Quality: {quality_grade}"
  },
  {
    type: "text",
    text: "Place guess: {place_guess}"
  }]
});

//create popup template for users
const userPopup = new PopupTemplate({
  title: "{name}",
  content: [{
    type: "text",
    text: "Observation count: {observation_count}"
  }]
});

//create popup template for species
const speciesPopup = new PopupTemplate({
  title: "{common_name}",
  content: [{
    type: "text",
    text: "Scientific Name: {name}"
  }]
});
//when layer loads, apply popups to sublayers
kgLayer.load().then(()=>{
  kgLayer.layers.items.forEach((sublayer)=> {
    switch(sublayer.title) {
      case 'Observation':
        sublayer.popupTemplate = observationPopup;
        break;
      case 'User':
        sublayer.popupTemplate = userPopup;
        break;
      case 'Species':
        sublayer.popupTemplate = speciesPopup;
        break;
      default:
        sublayer.popupTemplate = new PopupTemplate({
          title: "{globalid}"
        })
        break;
    }
  })
  map.add(kgLayer);
});
See also

Constructors

new KnowledgeGraphLayer(properties)
Parameter
properties Object
optional

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

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
String

The name of the class.

more details
Accessor
Extent

The full extent of the layer.

more details
Layer
String

The unique ID assigned to the layer.

more details
Layer
InclusionModeDefinition

Defines a set of named types and/or entities and relationships to be included in the layer.

more details
KnowledgeGraphLayer
KnowledgeGraph

The data model, service definition and url of the knowledge graph service that contains the data for the KnowledgeGraphLayer.

more details
KnowledgeGraphLayer
Collection<KnowledgeGraphSublayer>

A collection of operational KnowledgeGraphSublayer.

more details
KnowledgeGraphLayer
String

Indicates how the layer should display in the LayerList widget.

more details
Layer
Boolean

Indicates whether the layer's resources have loaded.

more details
Layer
Error

The Error object returned if an error occurred while loading.

more details
Layer
String

Represents the status of a load operation.

more details
Layer
Object[]

A list of warnings which occurred while loading.

more details
Layer
EntityType[]

The entity types included in the KnowledgeGraphLayer.

more details
KnowledgeGraphLayer
RelationshipType[]

The relationship types included in the KnowledgeGraphLayer.

more details
KnowledgeGraphLayer
Number

The opacity of the layer.

more details
Layer
Map|Basemap|Ground|GroupLayer

The parent to which the layer belongs.

more details
Layer
Boolean

When true, the layer can be persisted.

more details
Layer
Collection<KnowledgeGraphSublayer>

All non-spatial entity type and relationship type sublayers.

more details
KnowledgeGraphLayer
String

An optional title for the KnowledgeGraphLayer.

more details
KnowledgeGraphLayer
String

The layer type.

more details
KnowledgeGraphLayer
String

The url of the knowledge graph service.

more details
KnowledgeGraphLayer
Boolean

Indicates if the layer is visible in the View.

more details
Layer

Property Details

declaredClass Stringreadonly inherited

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

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;
});

The unique ID assigned to the layer. If not set by the developer, it is automatically generated when the layer is loaded.

inclusionModeDefinition InclusionModeDefinition

Defines a set of named types and/or entities and relationships to be included in the layer. If only a named type is specified, all instances of that type will be included in the layer. Sublayers can be created for all named types in the graph even if they have no instances specified in the member definition. The inclusion definition is not permanently dynamic. It captures the data at the time of creation. For example, if generateAllSublayers is true and a new entity type is added to the knowledge graph, that new entity type will not be added to the inclusion list. Similarly, if useAllData is true for a type, and a new record is added to that type, the newly added record will not be automatically added to the inclusionList.

Examples
// constructing an inclusion list:
// The exact record ids of each of the records of a specific named type (entity type or relationship type)
// to include in the layer. In this case the layer will contain one record
const layerInclusionMemberDefinition = new Map();
layerInclusionMemberDefinition.set("{1A4W8G4-W52G-W89G-1W5G-J1R4S8H52H4S}",{id:"{1A4W8G4-W52G-W89G-1W5G-J1R4S8H52H4S}"})

 //The layerInclusionDefinition specifies whether to use all of the data in a named type or only the records
// specified in the 'members' list. In this case we only want the records specified.
const layerInclusionDefinition = {
  useAllData: false, //only include instances in the member list
  members: layerInclusionMemberDefinition
};

// The namedTypeDefinition is a map of the typeName of each type to be included.
// In this case we are only including the "Observation" entity type.
// The layerInclusionDefinition specifies exactly which "Observation" entities to include in the layer.
const namedTypeDefinition = new Map();
namedTypeDefinition.set("Observation", layerInclusionDefinition);

// Specify if a sublayer should be generated for all named types.
// If true, a sublayer will be created for all named types regardless of
// whether they have a list of instances to include or not.
// If there are no instances the sublayer will be empty. In this case we have set 'generateAllSubLayers' to false so the
// layer will only contain sublayers for the named types (entity types or relationship types) that are specified
// in the namedTypeDefinitions.
// Also defines the collection of named types to include in the layer.
const inclusionListDefinition = {
  generateAllSublayers: false, //only create sublayers for the named types in the namedTypeDefintion
  namedTypeDefinitions: namedTypeDefinition
}
//examples of the inclusionModeDefinition structure inside the KnowledgeGraphLayer

//the layer will only contain one sublayer (for 'supplier') and that sublayer will consist of one entity.
{
  generateAllSublayers: false,
  namedTypeDefinition:[{
    key: "supplier",
    value:{
      useAllData: false,
      members: [{
        key: "{1A4W8G4-W52G-W89G-1W5G-J1R4S8H52H4S}",
        value: {
          id: "{1A4W8G4-W52G-W89G-1W5G-J1R4S8H52H4S}",
        }
      }]
    }
  }]
}

// this layer will contain a sublayer for all named types in the graph
// ('Observation', 'User', 'Species', "Observed", "Reviewed", "ObservedIn")
// but only the 'Observation' sublayer will contain data.
// The Observation sublayer will contain exactly one entity.
{
  generateAllSublayers: true,
  namedTypeDefinition:[{
    key: "Observation",
    value:{
      useAllData: false,
      members: [{
        key: "{32CBD5CB-EE31-4714-B14F-57BFE36AE094}",
        value: {
          id: "{32CBD5CB-EE31-4714-B14F-57BFE36AE094}",
        }
      }]
    }
  }]
}

// this layer will contain a sublayer for all named types in the graph
// ('Observation', 'User', 'Species', "Observed", "Reviewed", "ObservedIn")
// but only the 'Observation' sublayer will contain data.
// the 'Observation' sublayer will contain all instance of the Observation entity type
{
  generateAllSublayers: true,
  namedTypeDefinition:[{
    key: "Observation",
    value:{
      useAllData: true
    }
  }]
}

// A more complex example:
{
	//sublayers will only be created for the types listed
	generateAllSublayers: false,
	namedTypeDefinitions: {
		//include all `Species` entities that exist at the time the layer is created
		Species: {
			useAllData: true
		},
		//include all `User` entities that exist at the time the layer is created
		User: {
			useAllData: true
		},
		//include all only the specified `Observation` entities
		Observation: {
			useAllData:false,
			members: {
				"{941A7425-C45D-4940-A2E8-F3611973EC8A}": {
					id: "{941A7425-C45D-4940-A2E8-F3611973EC8A}"
				},
				"{94DC1D53-4043-4D0B-8CF7-18B690414118}": {
					id: "{94DC1D53-4043-4D0B-8CF7-18B690414118}"
				},
				//This entity has a fixed location so will remain in the same place regardless of the layout applied.
				//the other entities will move around it
				"{4E1D1ACE-6252-4BA4-B76E-CDEDFE9B0AB1}": {
					id: "{4E1D1ACE-6252-4BA4-B76E-CDEDFE9B0AB1}",
					linkChartLocation: new Point({x: 55.26841, y: 10.2884})
				},
				"{559312DF-893C-44E2-AD86-BAA73CD49719}": {
					id: "{559312DF-893C-44E2-AD86-BAA73CD49719}"
				},
				"{158A2D46-3EFF-4479-BC57-E6981FCB80B6}": {
					id: "{158A2D46-3EFF-4479-BC57-E6981FCB80B6}"
				},
				"{40AD70FC-CD7D-4928-B555-38EA49675944}": {
					id: "{40AD70FC-CD7D-4928-B555-38EA49675944}"
				},
				"{3A5B8F11-5971-4A46-99AC-F509CA59B517}": {
					id: "{3A5B8F11-5971-4A46-99AC-F509CA59B517}"
				}
			}
		},
		//include all `Observed` relationships that exist at the time the layer is created
		Observed: {
			useAllData: true
		},
		//include all `ObservedIn` relationships that exist at the time the layer is created
		ObservedIn: {
			useAllData: true
		}
	}
}
knowledgeGraph KnowledgeGraphreadonly

The data model, service definition and url of the knowledge graph service that contains the data for the KnowledgeGraphLayer.

A collection of operational KnowledgeGraphSublayer. Each layer represents an entity type or relationship type sublayer. Each feature contained in each sublayer has a geometry that allows it to be rendered as a graphic with spatial context on the view. Features within the layer may also contain data attributes that provide additional information that may be viewed in popup. These layers can also be queried and analyzed.

Example
//to access individual sublayers to add or modify properties such as the renderer, popups and labels
KnowledgeGraphLayer.layers.items.forEach((sublayer)=>{
 sublayer.popupTemplate = new PopupTemplate({
  title: "{common_name}",
  content: [{
    type: "text",
    text: "Scientific Name: {name}"
  }]
 });
})
listMode String inherited

Indicates how the layer should display in the LayerList widget. The possible values are listed below.

Value Description
show The layer is visible in the table of contents.
hide The layer is hidden in the table of contents.
hide-children If the layer is a GroupLayer, BuildingSceneLayer, KMLLayer, MapImageLayer, TileLayer or WMSLayer, hide the children layers from the table of contents.

Possible Values:"show"|"hide"|"hide-children"

Default Value:"show"
loaded Booleanreadonly inherited

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

Default Value:false
loadError Errorreadonly inherited

The Error object returned if an error occurred while loading.

Default Value:null
loadStatus Stringreadonly inherited

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 Object[]readonly inherited

A list of warnings which occurred while loading.

memberEntityTypes EntityType[]readonly

The entity types included in the KnowledgeGraphLayer.

memberRelationshipTypes RelationshipType[]readonly

The relationship types included in the KnowledgeGraphLayer.

opacity Number inherited

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;
Since: ArcGIS Maps SDK for JavaScript 4.27

The parent to which the layer belongs.

persistenceEnabled Boolean inherited
Since: ArcGIS Maps SDK for JavaScript 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

All non-spatial entity type and relationship type sublayers. They have the same structure as the spatial sublayers but the geometryType is null. These layers can also be queried and analyzed.

title String

An optional title for the KnowledgeGraphLayer.

type Stringreadonly

The layer type.

For KnowledgeGraphLayer the type is always "knowledge-graph".

url String

The url of the knowledge graph service.

visible Boolean inherited

Indicates if the layer is visible in the View. When false, the layer may still be added to a Map instance that is referenced in a view, but its features will not be visible in the view.

Default Value:true
Example
// The layer is no longer visible in the view
layer.visible = false;

Method Overview

Show inherited methods Hide inherited methods
Name Return Type Summary Class

Adds one or more handles which are to be tied to the lifecycle of the object.

more details
Accessor
Promise<void>

Adds new entities or relationships to the knowledge graph layer.

more details
KnowledgeGraphLayer

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

more details
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.

more details
Layer

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

more details
Layer
Boolean

Emits an event on the instance.

more details
Layer
Promise<object>

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

more details
Layer
Boolean

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

more details
Layer
Boolean

Returns true if a named group of handles exist.

more details
Accessor
Boolean

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

more details
Layer
Boolean

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

more details
Layer
Boolean

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

more details
Layer
Promise

Loads the resources referenced by this class.

more details
Layer

Assumes that data for all of the members defined in the inclusionModeDefinition is already loaded into local storage.

more details
KnowledgeGraphLayer
Object

Registers an event handler on the instance.

more details
Layer

Removes a group of handles owned by the object.

more details
Accessor
Promise<IdTypePair[]>

Removes entities or relationships from the knowledge graph layer.

more details
KnowledgeGraphLayer
Promise

when() may be leveraged once an instance of the class is created.

more details
Layer

Method Details

addHandles(handleOrHandles, groupKey)inherited

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.

addRecords(records){Promise<void>}static

Adds new entities or relationships to the knowledge graph layer. This method modifies the inclusionModeDefinition. If the entity type or relationship type of the record already exists in the graph, the record will be added to the appropriate sublayer. If the named type is not already in the knowledge graph layer a new sublayer will be added to the knowledge graph layer.

Known Limitations

addRecords can only be used on a knowledge graph layer that is defined with an inclusionModeDefinition.

Parameter
records IdTypePair[]

An array of the records to add to the knowledge graph layer.

Returns
Type Description
Promise<void>
  • Resolves when the records are retrieved from the knowledge graph service and added to the knowledge graph layer.
Example
const initializeLayer = async() => {
	//fetch the knowledge graph
	knowledgeGraph = await KnowledgeGraphService.fetchKnowledgeGraph(url)
	//query the knowledge graph to get only the research grade observations
	observationList = await KnowledgeGraphService.executeQuery(knowledgeGraph, {
			openCypherQuery: `MATCH (o:Observation{quality_grade: "research"}) RETURN o LIMIT 10`
	})
	//Define an inclusion list
	let members = new Map();
	for (observation of observationList.resultRows){
			members.set(observation[0].id,{id:observation[0].id})
	}
	let namedTypes = new Map();
	namedTypes.set("Observation", { useAllData: false, members: members });
	const inclusionDef = {
			generateAllSublayers: false,
			namedTypeDefinitions: namedTypes
	}
	//create the layer
	const compositeLayer = new KnowledgeGraphLayer({
			url: url,
			inclusionModeDefinition: inclusionDef
	});
	map.add(compositeLayer);
	//add records to the layer
	await compositeLayer.addRecords([{id:"{001899F8-6A59-462A-8507-DD65D690AD48}", typeName:"Observation"}])
}
initializeLayer()
cancelLoad()inherited

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

createLayerView(view, options){Promise<LayerView>}inherited

Called by the views, such as MapView and SceneView, when the layer is added to the Map.layers collection and a layer view must be created for it. This method is used internally and there is no use case for invoking it directly.

Parameters
view *

The parent view.

options Object
optional

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

Specification
signal AbortSignal
optional

A signal to abort the creation of the layerview.

Returns
Type Description
Promise<LayerView> Resolves with a LayerView instance.
See also
destroy()inherited

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

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

See also
emit(type, event){Boolean}inherited

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(){Promise<object>}inherited

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.
hasEventListener(type){Boolean}inherited

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(groupKey){Boolean}inherited

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(){Boolean}inherited

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(){Boolean}inherited

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(){Boolean}inherited

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(signal){Promise}inherited

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.
loadLayerAssumingLocalCache()static

Assumes that data for all of the members defined in the inclusionModeDefinition is already loaded into local storage. This will optimize layer load times.

on(type, listener){Object}inherited

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);
});
removeHandles(groupKey)inherited

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");
removeRecords(records){Promise<IdTypePair[]>}static

Removes entities or relationships from the knowledge graph layer. This method only removes records from the knowledge graph layer, all records will remain in the knowledge graph.

Known Limitations

removeRecords can only be used on records explicitly included as members in the inclusionModeDefinition. You cannot removed records from named type KnowledgeGraphSublayers that have useAllData:True or knowledge graph layers with no inclusionModeDefinition.

Parameter
records IdTypePair[]

The id and entity type or relationship type of the record to be added to the knowledge graph layer.

Returns
Type Description
Promise<IdTypePair[]>
  • The IdTypePairs for the records removed from the knowledge graph layer.
Example
const initializeLayer = async() => {
	//fetch the knowledge graph
	knowledgeGraph = await KnowledgeGraphService.fetchKnowledgeGraph(url)
	//query the knowledge graph to get only the research grade observations
	observationList = await KnowledgeGraphService.executeQuery(knowledgeGraph, {
			openCypherQuery: `MATCH (o:Observation{quality_grade: "research"}) RETURN o LIMIT 10`
	})
	//Define an inclusion list. Records can only be removed from the knowledge graph layer
 // if they are explicitly included as members of a named type in the inclusionModeDefinition
	let members = new Map();
	for (observation of observationList.resultRows){
			members.set(observation[0].id,{id:observation[0].id})
	}
	let namedTypes = new Map();
	namedTypes.set("Observation", { useAllData: false, members: members });
	const inclusionDef = {
			generateAllSublayers: false,
			namedTypeDefinitions: namedTypes
	}
	//create the layer
	const compositeLayer = new KnowledgeGraphLayer({
			url: url,
			inclusionModeDefinition: inclusionDef
	});
	map.add(compositeLayer);
	//remove records from the inclusionModeDefinition
	await compositeLayer.removeRecords([{id:"{001899F8-6A59-462A-8507-DD65D690AD48}", typeName:"Observation"}])
}
initializeLayer()
when(callback, errback){Promise}inherited

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

IdTypePair Object

The id and named type of a record to be added or removed from the knowledge graph.

Properties
id String

The global ID of the record to be added to or removed from the the knowledge graph layer.

typeName String

the named type of the record to be added or removed from the knowledge graph layer.

InclusionModeDefinition Object

Defines the sublayer structure and the named types that will be in the KnowledgeGraphLayer

Properties
generateAllSublayers Boolean

Specifies whether to create sublayers for each named type regardless of whether or not they are included in the namedTypeDefinition. If true all named types (EntityType and RelationshipType) will be added as an empty sublayer.

namedTypeDefinitions Map<string, LayerInclusionDefinition>

A map of named types and the specific instances of those types to include in the layer.

LayerInclusionDefinition Object

Defines the contents of each specified named type in the inclusionModeDefinition and whether all instance of the named type will be used or a specified subset.

Properties
useAllData Boolean

If true all of the instances of the named type will be included regardless of if there is a defined list of members. If false only the instances specified in the members property will be included.

A map of the specific members of the named type to be included. The key is the global ID of the instance.

LayerInclusionMemberDefinition Object

Defines the list of members for a named type in the inclusionModeDefinition.

Property
id String

The global ID of the specific instance of the named type to be included in the layer.

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.

more details
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.

more details
Layer
{view: View,layerView: LayerView}

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

more details
Layer

Event Details

layerview-createinherited

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-errorinherited

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-destroyinherited

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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