StreamLayerView

Class: esri/views/layers/StreamLayerView
Inheritance: StreamLayerView LayerView Accessor
Since: ArcGIS Maps SDK for JavaScript 4.4

Represents the LayerView of a StreamLayer after it has been added to a Map in either a MapView or SceneView.

The StreamLayerView is responsible for rendering a StreamLayer's features as graphics in the View. The methods in the StreamLayerView provide developers with the ability to query and highlight graphics in the view. See the code snippets in the methods below for examples of how to access client-side graphics from the view.

It connects to a server that emits geographic features continuously. The stream layer is suitable when you would like to map dynamic streams of data that are unbounded and continuous. When a StreamLayer is added to a map, users are able to see any real-time updates pushed out by the server. For more information, read the documentation of StreamLayer.

See also

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
Error

The error that explains an unsuccessful attempt to connect to the stream service or an unexpected disconnection from the stream service.

StreamLayerView
String

The status of the Web Socket connection with the stream service.

StreamLayerView
String

The name of the class.

Accessor
FeatureEffect

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

StreamLayerView
FeatureFilter

The attribute, geometry, and time extent filter.

StreamLayerView
HighlightOptions

Options for configuring the highlight.

StreamLayerView
Layer

The layer being viewed.

LayerView
Boolean

Indicates if the spatialReference of the MapView is supported by the layer view.

LayerView
Boolean

Value is true if the layer is suspended (i.e., layer will not redraw or update itself when the extent changes).

LayerView
Boolean

Indicates if the layer view is making any updates that will impact what is displayed on the map.

LayerView
MapView|SceneView

A reference to the MapView or SceneView associated with the layer view.

LayerView
Boolean

When true, the layer is visible in the view.

LayerView

Property Details

connectionError

Property
connectionError Errorreadonly

The error that explains an unsuccessful attempt to connect to the stream service or an unexpected disconnection from the stream service.

connectionStatus

Property
connectionStatus Stringreadonly

The status of the Web Socket connection with the stream service. This property can be watched to see if the connection is lost unexpectedly.

Release specific changes:

  • At version 4.29, connect() and disconnect() methods were added. Consequently, invoking the disconnect() method following a pause will transition the connection status from paused to disconnected. Subsequent use of the connect() method will then change the connection status to connected.
  • At version 4.26, the connectionStatus can be paused if the pause() method is called or if the layer becomes suspended.

Possible Values:"connected"|"disconnected"|"paused"

declaredClass

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

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

featureEffect

Property
featureEffect FeatureEffectautocast
Since: ArcGIS Maps SDK for JavaScript 4.22 StreamLayerView since 4.4, featureEffect added at 4.22.

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.

If the featureEffect is set on the layer, it will be inherited by layerView.featureEffect unless the developer overrides it on the layerView. The layerView.featureEffect will take precedence over layer.featureEffect if both properties are set.

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
layerView.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'"
});
layerView.featureEffect = new FeatureEffect({
  filter: featureFilter,
  includedEffect: "drop-shadow(3px, 3px, 3px, black)",
  excludedEffect: "blur(1px) brightness(65%)"
});

filter

Property
filter FeatureFilterautocast
Since: ArcGIS Maps SDK for JavaScript 4.11 StreamLayerView since 4.4, filter added at 4.11.

The attribute, geometry, and time extent filter. Only the features that satisfy the filter are displayed on the view.

Example
// display earthquakes that have
// magnitude value of 3 or higher
layerView.filter = new FeatureFilter({
  where: "mag >= 3",
});

highlightOptions

Property
highlightOptions HighlightOptions
Since: ArcGIS Maps SDK for JavaScript 4.26 StreamLayerView since 4.4, highlightOptions added at 4.26.

Options for configuring the highlight. Use the highlight() method on the layer view to highlight a feature. The layerView's highlightOptions will take precedence over the view's highlightOptions if both properties are set.

Known Limitations

  • The highlightOptions on layer views are only supported in 2D MapView.
Example
// Features in the layerview will be highlighted with bright
// yellow colors in the map.
const layerView = await view.whenLayerView(layer);
layerView.highlightOptions = {
  color: [255, 255, 0, 1],
  haloOpacity: 0.9,
  fillOpacity: 0.2
};

layer

Inherited
Property
layer Layerreadonly
Inherited from LayerView

The layer being viewed.

spatialReferenceSupported

Inherited
Property
spatialReferenceSupported Booleanreadonly
Inherited from LayerView
Since: ArcGIS Maps SDK for JavaScript 4.23 LayerView since 4.0, spatialReferenceSupported added at 4.23.

Indicates if the spatialReference of the MapView is supported by the layer view. When false layer view will be suspended.

See also

suspended

Inherited
Property
suspended Booleanreadonly
Inherited from LayerView

Value is true if the layer is suspended (i.e., layer will not redraw or update itself when the extent changes).

updating

Inherited
Property
updating Booleanreadonly
Inherited from LayerView

Indicates if the layer view is making any updates that will impact what is displayed on the map. For example, this value is true when renderer, definitionExpression, filter or effect is changed or if the layer view is in the process of the fetching data.

Watch dataUpdating property instead to only know when the data has been updated (e.g. to run statistics query on all feature available in the layer view).

Default Value:false
Example
// Check for the first time layerView.updating becomes false. Then query for
// features that are visible within the view associated with the layer view.
await reactiveUtils.whenOnce(() => !layerView.updating);
const query = layerView.createQuery();
query.geometry = layerView.view.extent;
const result = layerView.queryFeatures(query);

view

Inherited
Property
view MapView|SceneViewreadonly
Inherited from LayerView
Since: ArcGIS Maps SDK for JavaScript 4.28 LayerView since 4.0, view added at 4.28.

A reference to the MapView or SceneView associated with the layer view.

Example
// Check for the first time layerView.updating becomes false. Then query for
// features that are visible within the view associated with the layer view.
await reactiveUtils.whenOnce(() => !layerView.updating);
const query = layerView.createQuery();
query.geometry = layerView.view.extent;
const result = layerView.queryFeatures(query);

visible

Inherited
Property
visible Boolean
Inherited from LayerView

When true, the layer is visible in the view. Value of this property is inherited from the layer.visible unless the developer overrides it. The layerView.visible will take precedence over layer.visible if both properties are set.

Default Value:true

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

Connects to a stream service web socket.

StreamLayerView
Query

Creates a query parameter object that can be used to fetch features as they are being displayed.

StreamLayerView

Disconnects from a stream service web socket.

StreamLayerView
Boolean

Emits an event on the instance.

StreamLayerView
Boolean

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

StreamLayerView
Boolean

Returns true if a named group of handles exist.

Accessor
Handle

Highlights the given feature(s) in a layer view.

StreamLayerView
Boolean

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

LayerView
Boolean

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

LayerView
Boolean

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

LayerView
Object

Registers an event handler on the instance.

StreamLayerView

Pauses the connection and stops new observations from being applied until resume() is called.

StreamLayerView
Promise<object>

Executes a Query against features available for drawing in the layerView and returns the Extent of features that satisfy the query.

StreamLayerView
Promise<number>

Executes a Query against features available for drawing in the layerView and returns the number of features that satisfy the query.

StreamLayerView
Promise<FeatureSet>

Executes a Query against features available for drawing in the layerView and returns a FeatureSet.

StreamLayerView
Promise<FeatureSet>

If a trackIdField is specified on the stream service, this method executes a Query against features available for drawing in the layerView and returns a FeatureSet of the latest observations for each trackId that satisfy the query.

StreamLayerView
Promise<number[]>

Executes a Query against features available for drawing in the layerView and returns array of the ObjectIDs of features that satisfy the input query.

StreamLayerView

Removes a group of handles owned by the object.

Accessor

Resumes the connection and the new observations will be applied.

StreamLayerView
Promise

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

LayerView

Method Details

addHandles

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

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

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

this.addHandles(handle);

// Destroy the object
this.destroy();
Parameters
handleOrHandles WatchHandle|WatchHandle[]

Handles marked for removal once the object is destroyed.

groupKey *
optional

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

connect

Method
connect()
Since: ArcGIS Maps SDK for JavaScript 4.29 StreamLayerView since 4.4, connect added at 4.29.

Connects to a stream service web socket. The web socket will start streaming new observations. It changes the connectionStatus to connected.

See also

createQuery

Method
createQuery(){Query}
Since: ArcGIS Maps SDK for JavaScript 4.27 StreamLayerView since 4.4, createQuery added at 4.27.

Creates a query parameter object that can be used to fetch features as they are being displayed. It sets the query parameter's outFields property to ["*"] and returnGeometry to true. The outSpatialReference is set to the spatial reference of the view. Parameters of the filter currently applied to the layer view are also incorporated in the returned query object. The results will include geometries of features and values for all fields.

Returns
Type Description
Query The query object
Example
const query = streamLayerView.createQuery();
query.where = "status = 'in progress'";
csvLayerView.queryFeatures(query).then(function(results) {
  console.log(results);
})
.catch(function(error) {
  console.log(error);
});

disconnect

Method
disconnect()
Since: ArcGIS Maps SDK for JavaScript 4.29 StreamLayerView since 4.4, disconnect added at 4.29.

Disconnects from a stream service web socket. New observations will not be streamed until connect() method is called. It changes the connectionStatus to disconnected.

See also

emit

Method
emit(type, event){Boolean}
Since: ArcGIS Maps SDK for JavaScript 4.5 StreamLayerView since 4.4, emit added at 4.5.

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

Parameters
type String

The name of the event.

event Object
optional

The event payload.

Returns
Type Description
Boolean true if a listener was notified

hasEventListener

Method
hasEventListener(type){Boolean}

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

Parameter
type String

The name of the event.

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

hasHandles

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

Returns true if a named group of handles exist.

Parameter
groupKey *
optional

A group key.

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

highlight

Method
highlight(target){Handle}

Highlights the given feature(s) in a layer view. The layerView's highlightOptions will take precedence over the view's highlightOptions if both properties are set.

Release specific changes:

Parameter
optional

The feature(s) to highlight. When passing a graphic or array of graphics, each feature must have a valid objectID. You may alternatively pass one or more objectIDs as a single number, string or an array of numbers or strings.

Returns
Type Description
Handle Returns a highlight handler with a remove() method that can be called to remove the highlight.
Examples
// highlight features based on a query result
let highlight;
view.whenLayerView(treesLayer).then(function(layerView){
  layerView.highlightOptions = {
    color: "#FF00FF", //bright fuchsia
    haloOpacity: 0.8,
    fillOpacity: 0.3
  };
  let query = treesLayer.createQuery();
  query.where = "type = 'Quercus'";
  treesLayer.queryFeatures(query).then(function(result){
    highlight?.remove();
    highlight = layerView.highlight(result.features);
  });
});
// highlight feature on pointer-move
view.on("pointer-move", function(event){
  view.hitTest(event).then(function(response){
    if (response.results.length) {
      let graphic = response.results.filter(function (result) {
        return result.graphic.layer === treesLayer;
      })[0].graphic;

     view.whenLayerView(graphic.layer).then(function(layerView){
       layerView.highlight(graphic);
     });
    }
  });
});

isFulfilled

Inherited
Method
isFulfilled(){Boolean}
Inherited from LayerView

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 LayerView

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 LayerView

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.

on

Method
on(type, listener){Object}

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);
});

pause

Method
pause()
Since: ArcGIS Maps SDK for JavaScript 4.26 StreamLayerView since 4.4, pause added at 4.26.

Pauses the connection and stops new observations from being applied until resume() is called. The web socket is open and is still sending data but the layer view will not update. It changes the connectionStatus to paused.

At version 4.29, invoking the disconnect() method following a pause will transition the connectionStatus from paused to disconnected. Subsequent use of the connect() method will then change the connectionStatus to connected.

See also

queryExtent

Method
queryExtent(query, options){Promise<object>}
Since: ArcGIS Maps SDK for JavaScript 4.9 StreamLayerView since 4.4, queryExtent added at 4.9.

Executes a Query against features available for drawing in the layerView and returns the Extent of features that satisfy the query. If query parameters are not provided, the extent and count of all features available for drawing are returned.

Known Limitations

  • Spatial queries have the same limitations as those listed in the projection engine documentation.
  • Spatial queries are not currently supported if the layerView has any of the following SpatialReferences:
    • GDM 2000 (4742) – Malaysia
    • Gusterberg (Ferro) (8042) – Austria/Czech Republic
    • ISN2016 (8086) - Iceland
    • SVY21 (4757) - Singapore
Parameters
query Query autocast
optional
Autocasts from Object

Specifies the attributes, spatial, and temporal filter of the query. When no parameters are passed to this method, all features in the client are returned. To only return features visible in the view, set the geometry parameter in the query object to the view's extent.

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 | null The extent of the features that satisfy the query.
Example
let layer = new StreamLayer({
  url: streamLayerUrl  // URL to a stream service
});

const layerView = await view.whenLayerView(layer);
await reactiveUtils.whenOnce(() => !layerView.updating);

const results = await layerView.queryExtent()
view.goTo(results.extent);  // go to the extent of all the graphics in the layerView

queryFeatureCount

Method
queryFeatureCount(query, options){Promise<number>}
Since: ArcGIS Maps SDK for JavaScript 4.9 StreamLayerView since 4.4, queryFeatureCount added at 4.9.

Executes a Query against features available for drawing in the layerView and returns the number of features that satisfy the query. If query parameters are not provided, the count of all features available for drawing is returned.

Known Limitations

  • Spatial queries have the same limitations as those listed in the projection engine documentation.
  • Spatial queries are not currently supported if the layerView has any of the following SpatialReferences:
    • GDM 2000 (4742) – Malaysia
    • Gusterberg (Ferro) (8042) – Austria/Czech Republic
    • ISN2016 (8086) - Iceland
    • SVY21 (4757) - Singapore
Parameters
query Query autocast
optional
Autocasts from Object

Specifies the attributes, spatial, and temporal filter of the query. When no parameters are passed to this method, all features in the client are returned. To only return features visible in the view, set the geometry parameter in the query object to the view's extent.

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 satisfying the query.
Examples
view.on("click", function(event){

  let query = new Query();
  query.geometry = event.mapPoint;  // obtained from a view click event
  query.spatialRelationship = "intersects";

  view.whenLayerView(layer).then(function(layerView){
    reactiveUtils.whenOnce(() => !layerView.updating)
    .then(function(){
      return layerView.queryFeatureCount(query);
    })
    .then(function(count){
      console.log(count);  // prints the number of the client-side graphics that satisfy the query
    });
  });
});
view.whenLayerView(layer).then(function(layerView){
  return layerView.queryFeatureCount()
}).then(function(count){
  console.log(count);  // prints the total number of client-side graphics to the console
});

queryFeatures

Method
queryFeatures(query, options){Promise<FeatureSet>}
Since: ArcGIS Maps SDK for JavaScript 4.9 StreamLayerView since 4.4, queryFeatures added at 4.9.

Executes a Query against features available for drawing in the layerView and returns a FeatureSet. If query parameters are not provided, all features available for drawing are returned.

Known Limitations

  • Spatial queries have the same limitations as those listed in the projection engine documentation.
  • Spatial queries are not currently supported if the layerView has any of the following SpatialReferences:
    • GDM 2000 (4742) – Malaysia
    • Gusterberg (Ferro) (8042) – Austria/Czech Republic
    • ISN2016 (8086) - Iceland
    • SVY21 (4757) - Singapore
Parameters
query Query autocast
optional
Autocasts from Object

Specifies the attributes, spatial, and temporal filter of the query. When no parameters are passed to this method, all features in the client are returned. To only return features visible in the view, set the geometry parameter in the query object to the view's extent.

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
const layerView = await view.whenLayerView(layer);
await reactiveUtils.whenOnce(() => !layerView.updating);

const results = await layerView.queryFeatures(query);
console.log(results.features);  // prints the array of client-side graphics to the console
// returns all the graphics from the layerView
const layerView = await view.whenLayerView(layer);
await reactiveUtils.whenOnce(() => !layerView.updating);

const results = await layerView.queryFeatures()
console.log(results.features);  // prints all the client-side graphics to the console

queryLatestObservations

Method
queryLatestObservations(query, options){Promise<FeatureSet>}
Since: ArcGIS Maps SDK for JavaScript 4.9 StreamLayerView since 4.4, queryLatestObservations added at 4.9.

If a trackIdField is specified on the stream service, this method executes a Query against features available for drawing in the layerView and returns a FeatureSet of the latest observations for each trackId that satisfy the query. Otherwise, an Error will be thrown when the method is called.

Known Limitations

  • Spatial queries have the same limitations as those listed in the projection engine documentation.
  • Spatial queries are not currently supported if the layerView has any of the following SpatialReferences:
    • GDM 2000 (4742) – Malaysia
    • Gusterberg (Ferro) (8042) – Austria/Czech Republic
    • ISN2016 (8086) - Iceland
    • SVY21 (4757) - Singapore
Parameters
query Query autocast
optional
Autocasts from Object

Specifies the attributes, spatial, and temporal filter of the query. When no parameters are passed to this method, all features in the client are returned. To only return features visible in the view, set the geometry parameter in the query object to the view's extent.

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, returns the FeatureSet that satisfy the input query.
Example
let layer = new StreamLayer({
  url: streamLayerUrl  // URL to a Stream Service
});

const layerView = await view.whenLayerView(layer);
await reactiveUtils.whenOnce(() => !layerView.updating);

const results = await layerView.queryLatestObservations()
console.log(results.features);  // prints all the client-side graphics to the console

queryObjectIds

Method
queryObjectIds(query, options){Promise<number[]>}
Since: ArcGIS Maps SDK for JavaScript 4.9 StreamLayerView since 4.4, queryObjectIds added at 4.9.

Executes a Query against features available for drawing in the layerView and returns array of the ObjectIDs of features that satisfy the input query. If query parameters are not provided, the ObjectIDs of all features available for drawing are returned.

Known Limitations

  • Spatial queries have the same limitations as those listed in the projection engine documentation.
  • Spatial queries are not currently supported if the layerView has any of the following SpatialReferences:
    • GDM 2000 (4742) – Malaysia
    • Gusterberg (Ferro) (8042) – Austria/Czech Republic
    • ISN2016 (8086) - Iceland
    • SVY21 (4757) - Singapore
Parameters
query Query autocast
optional
Autocasts from Object

Specifies the attributes, spatial, and temporal filter of the query. When no parameters are passed to this method, all features in the client are returned. To only return features visible in the view, set the geometry parameter in the query object to the view's extent.

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 ObjectIDs of the features satisfying the query.
Examples
view.on("click", function(event){

  let query = new Query();
  query.geometry = event.mapPoint;  // obtained from a view click event
  query.spatialRelationship = "intersects";

  view.whenLayerView(layer).then(function(layerView){
    reactiveUtils.whenOnce(() => !layerView.updating)
    .then(function(){
      return layerView.queryObjectIds(query);
    })
    .then(function(ids){
      console.log(ids);  // prints the ids of the client-side graphics to the console
    });
  });
});
// returns all the Ids from the graphics in the layerView
view.whenLayerView(layer).then(function(layerView){
  return layerView.queryObjectIds()
}).then(function(ids){
  console.log(ids);  // prints the ids of all the client-side graphics to the console
});

removeHandles

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

Removes a group of handles owned by the object.

Parameter
groupKey *
optional

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

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

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

resume

Method
resume()
Since: ArcGIS Maps SDK for JavaScript 4.26 StreamLayerView since 4.4, resume added at 4.26.

Resumes the connection and the new observations will be applied. The layer view will update to show changes. It changes the connectionStatus to connected if the connection is successful. If the connectionStatus is set to disconnected, invoking this method will have no impact.

See also

when

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

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

Parameters
callback Function
optional

The function to call when the promise resolves.

errback Function
optional

The function to execute when the promise fails.

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

Event Overview

Name Type Summary Class
{attributes: Object,geometry: Object}

Fires when the layer view receives features.

StreamLayerView
{message: Object}

Fires when the layer view receives a message sent to the websocket connection.

StreamLayerView
{client: Number,websocket: Number}

Fires after the layer starts receiving updates from the stream service.

StreamLayerView

Event Details

data-received

Event
data-received

Fires when the layer view receives features. The event payload contains the attributes and geometry of a feature received from the stream service.

Properties
attributes Object

Name-value pairs of fields and field values associated with the received data.

geometry Object

A location of the received data containing x, y coordinates for points, paths for lines, and rings for polygons, along with the spatial reference wkid.

message-received

Event
message-received
Since: ArcGIS Maps SDK for JavaScript 4.26 StreamLayerView since 4.4, message-received added at 4.26.

Fires when the layer view receives a message sent to the websocket connection.

Property
message Object

The message object sent to the websocket connection.

update-rate

Event
update-rate
Since: ArcGIS Maps SDK for JavaScript 4.17 StreamLayerView since 4.4, update-rate added at 4.17.

Fires after the layer starts receiving updates from the stream service. It will return the websocket and the client update rates per second. The update rate indicates number of features are being pushed from the server and being processed on the client side. The client update rate will be approximately equal to the websocket update rate unless the service is pushing updates at a rate faster than the client can handle. In which case, the API will down-throttle the update rate and will cause the client update rate to be lower.

Properties
client Number

The client update rate per second. Returns number of features being processed on the client.

websocket Number

Update rate per second for websocket/service. Returns number of features being pushed from the server.

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