require(["esri/layers/KnowledgeGraphLayer"], (KnowledgeGraphLayer) => { /* code goes here */ });
import KnowledgeGraphLayer from "@arcgis/core/layers/KnowledgeGraphLayer.js";
esri/layers/KnowledgeGraphLayer
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 and saved to an module:/esri/WebMap, but it may not be supported in 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
-
Parameterproperties Objectoptional
See the properties for a list of all the properties that may be passed into the constructor.
Property Overview
Name | Type | Summary | Class |
---|---|---|---|
The name of the class. | Accessor | ||
The full extent of the layer. | Layer | ||
The unique ID assigned to the layer. | Layer | ||
Defines a set of named types and/or entities and relationships to be included in the layer. | KnowledgeGraphLayer | ||
The data model, service definition and url of the knowledge graph service that contains the data for the KnowledgeGraphLayer. | KnowledgeGraphLayer | ||
A collection of operational KnowledgeGraphSublayer. | KnowledgeGraphLayer | ||
Indicates how the layer should display in the LayerList widget. | Layer | ||
Indicates whether the layer's resources have loaded. | 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 | ||
The entity types included in the KnowledgeGraphLayer. | KnowledgeGraphLayer | ||
The relationship types included in the KnowledgeGraphLayer. | KnowledgeGraphLayer | ||
The opacity of the layer. | Layer | ||
The parent to which the layer belongs. | Layer | ||
When | Layer | ||
Contains the sublayer ids that have been cached. | KnowledgeGraphLayer | ||
All non-spatial entity type and relationship type sublayers. | KnowledgeGraphLayer | ||
An optional title for the KnowledgeGraphLayer. | KnowledgeGraphLayer | ||
The layer type. | KnowledgeGraphLayer | ||
The url of the knowledge graph service. | KnowledgeGraphLayer | ||
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
-
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; });
-
inclusionModeDefinition
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
istrue
and a new entity type is added to the knowledge graph, that new entity type will not be added to the inclusion list. Similarly, ifuseAllData
istrue
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 namedTypeDefinition 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
knowledgeGraph KnowledgeGraphreadonly
-
The data model, service definition and url of the knowledge graph service that contains the data for the KnowledgeGraphLayer.
-
layers
layers Collection<KnowledgeGraphSublayer>readonly
-
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
InheritedPropertylistMode 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"
-
loadStatus
InheritedPropertyloadStatus 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
-
Inherited from Layer
-
A list of warnings which occurred while loading.
-
memberEntityTypes
memberEntityTypes EntityType[]readonly
-
The entity types included in the KnowledgeGraphLayer.
-
memberRelationshipTypes
memberRelationshipTypes RelationshipType[]readonly
-
The relationship types included in the KnowledgeGraphLayer.
-
parent
InheritedPropertyparent Map |Basemap |Ground |GroupLayer |CatalogDynamicGroupLayer |CatalogLayer
Inherited from LayerSince: ArcGIS Maps SDK for JavaScript 4.27Layer since 4.0, parent added at 4.27. -
The parent to which the layer belongs.
-
persistenceEnabled
InheritedPropertypersistenceEnabled Boolean
Inherited from LayerSince: ArcGIS Maps SDK for JavaScript 4.28Layer 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
-
Contains the sublayer ids that have been cached.
-
tables
tables Collection<KnowledgeGraphSublayer>readonly
-
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.
-
type
type Stringreadonly
-
The layer type.
For KnowledgeGraphLayer the type is always "knowledge-graph".
-
The url of the knowledge graph service.
-
visibilityTimeExtent
InheritedPropertyvisibilityTimeExtent TimeExtent |null |undefinedautocast
Inherited from LayerSince: ArcGIS Maps SDK for JavaScript 4.30Layer since 4.0, visibilityTimeExtent added at 4.30. -
Specifies a fixed time extent during which a layer should be visible. This property can be used to configure a layer that does not have time values stored in an attribute field to work with time. Once configured, the TimeSlider widget will display the layer within the set time extent. In the case that only one of the start or end date values are available, the layer remains visible indefinitely in the direction where there is no time value.
Aerial imagery can capture seasonal variations in vegetation, water bodies, and land use patterns. For example, in agricultural regions, aerial imageries taken during different growing seasons provide insights into crop health and productivity. Defining a fixed time extent on imageries from specific time periods provides temporal context and facilitates focused analysis based on specific time periods or events.
- Default Value:null
- See also
-
visible
InheritedPropertyvisible Boolean
Inherited from Layer -
Indicates if the layer is visible in the View. When
false
, the layer may still be added to a Map instance that is referenced in a view, but its features will not be visible in the view.- Default Value:true
Example// The layer is no longer visible in the view layer.visible = false;
Method Overview
Name | Return Type | Summary | Class |
---|---|---|---|
Adds one or more handles which are to be tied to the lifecycle of the object. | Accessor | ||
Promise<void> | Adds new entities or relationships to the knowledge graph layer. | KnowledgeGraphLayer | |
Cancels a load() operation if it is already in progress. | 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. | Layer | ||
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 | ||
Fetches custom attribution data for the layer when it becomes available. | Layer | ||
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 | ||
| Layer | ||
| Layer | ||
| Layer | ||
Loads the resources referenced by this class. | Layer | ||
Assumes that data for all of the members defined in the inclusionModeDefinition is already loaded into local storage. | KnowledgeGraphLayer | ||
Registers an event handler on the instance. | Layer | ||
Removes a group of handles owned by the object. | Accessor | ||
Removes entities or relationships from the knowledge graph layer. | KnowledgeGraphLayer | ||
| Layer |
Method Details
-
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();
ParametershandleOrHandles WatchHandle|WatchHandle[]Handles marked for removal once the object is destroyed.
groupKey *optionalKey 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
addRecords(records){Promise<void>}
-
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 aninclusionModeDefinition
.Parameterrecords IdTypePair[]An array of the records to add to the knowledge graph layer.
ReturnsType Description Promise<void> - Resolves when the records are retrieved from the knowledge graph service and added to the knowledge graph layer.
Exampleconst 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()
-
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.
Parametersview *The parent view.
options ObjectoptionalAn object specifying additional options. See the object specification table below for the required properties of this object.
Specificationsignal AbortSignaloptionalA signal to abort the creation of the layerview.
Returns- See also
-
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.
-
Inherited from Layer
-
Fetches custom attribution data for the layer when it becomes available.
Returns
-
hasEventListener
InheritedMethodhasEventListener(type){Boolean}
Inherited from Layer -
Indicates whether there is an event listener on the instance that matches the provided event name.
Parametertype StringThe name of the event.
ReturnsType Description Boolean Returns true if the class supports the input event.
-
hasHandles
InheritedMethodhasHandles(groupKey){Boolean}
Inherited from Accessor -
Returns true if a named group of handles exist.
ParametergroupKey *optionalA group key.
ReturnsType 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
InheritedMethodisFulfilled(){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.ReturnsType Description Boolean Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected).
-
isRejected
InheritedMethodisRejected(){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.ReturnsType Description Boolean Indicates whether creating an instance of the class has been rejected.
-
isResolved
InheritedMethodisResolved(){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.ReturnsType Description Boolean Indicates whether creating an instance of the class has been resolved.
-
load
InheritedMethodload(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 aLoadable
instance load status. When the signal is aborted, the instance does not stop its loading process, only cancelLoad can abort it.Parametersignal AbortSignaloptionalSignal 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
-
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
InheritedMethodon(type, listener){Object}
Inherited from Layer -
Registers an event handler on the instance. Call this method to hook an event with a listener.
ParametersReturnsType 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. Exampleview.on("click", function(event){ // event is the event handle returned after the event fires. console.log(event.mapPoint); });
-
Inherited from Accessor
-
Removes a group of handles owned by the object.
ParametergroupKey *optionalA group key or an array or collection of group keys to remove.
Exampleobj.removeHandles(); // removes handles from default group obj.removeHandles("handle-group"); obj.removeHandles("other-handle-group");
-
removeRecords
removeRecords(records){Promise<IdTypePair[]>}
-
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 remove records from named type KnowledgeGraphSublayers that haveuseAllData:True
or knowledge graph layers with no inclusionModeDefinition.Parameterrecords IdTypePair[]The id and entity type or relationship type of the record to be added to the knowledge graph layer.
ReturnsType Description Promise<IdTypePair[]> - The IdTypePairs for the records removed from the knowledge graph layer.
Exampleconst 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
InheritedMethodwhen(callback, errback){Promise}
Inherited from Layer -
when()
may be leveraged once an instance of the class is created. This method takes two input parameters: acallback
function and anerrback
function. Thecallback
executes when the instance of the class loads. Theerrback
executes if the instance of the class fails to load.ParametersReturnsType 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
IdTypePair Object
-
The id and named type of a record to be added or removed from the knowledge graph.
-
InclusionModeDefinition
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
. Iftrue
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
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. Iffalse
only the instances specified in themembers
property will be included.members Map<string, LayerInclusionMemberDefinition>A map of the specific members of the named type to be included. The key is the global ID of the instance.
-
LayerInclusionMemberDefinition
LayerInclusionMemberDefinition Object
-
Defines the list of
members
for a named type in theinclusionModeDefinition
.- Property
-
id String
The global ID of the specific instance of the named type to be included in the layer.
Event Overview
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
-
Inherited from Layer
-
Fires after the layer's LayerView is created and rendered in a view.
- Properties
- 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; });
-
Inherited from Layer
-
Fires when an error emits during the creation of a LayerView after a layer has been added to the map.
- Properties
- 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); });