esri/views/layers/StreamLayerView
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.
Property Overview
Name | Type | Summary | Class |
---|---|---|---|
The error that explains an unsuccessful attempt to connect to the stream service or an unexpected disconnection from the stream service. | StreamLayerView | ||
The status of the Web Socket connection with the stream service. | StreamLayerView | ||
The name of the class. | Accessor | ||
The featureEffect can be used to draw attention features of interest. | StreamLayerView | ||
The attribute, geometry, and time extent filter. | StreamLayerView | ||
Options for configuring the highlight. | StreamLayerView | ||
The layer being viewed. | LayerView | ||
Indicates if the spatialReference of the MapView is supported by the layer view. | LayerView | ||
Value is | LayerView | ||
Indicates if the layer view is making any updates that will impact what is displayed on the map. | LayerView | ||
A reference to the MapView or SceneView associated with the layer view. | LayerView | ||
When | LayerView | ||
When | LayerView | ||
When | LayerView |
Property Details
-
connectionError
connectionError Errorreadonly
-
The error that explains an unsuccessful attempt to connect to the stream service or an unexpected disconnection from the stream service.
-
connectionStatus
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 apause
will transition the connection status frompaused
todisconnected
. Subsequent use of theconnect()
method will then change the connection status toconnected
. - At version 4.26, the
connectionStatus
can bepaused
if the pause() method is called or if the layer becomes suspended.
Possible Values:"connected" |"disconnected" |"paused"
- At version 4.29, connect() and disconnect() methods were added. Consequently, invoking the
-
featureEffect
featureEffect FeatureEffect |null |undefinedautocast
Since: ArcGIS Maps SDK for JavaScript 4.22StreamLayerView 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 bylayerView.featureEffect
unless the developer overrides it on the layerView. ThelayerView.featureEffect
will take precedence overlayer.featureEffect
if both properties are set.Known Limitations
- FeatureEffect is not supported in the following scenarios:
- In 3D SceneViews
- When FeatureReductionCluster is enabled
- When a map is printed
- A FeatureEffect set on a layerView cannot persisted in a WebMap.
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%)" });
- FeatureEffect is not supported in the following scenarios:
-
filter
filter FeatureFilterautocast
Since: ArcGIS Maps SDK for JavaScript 4.11StreamLayerView 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
highlightOptions HighlightOptions
Since: ArcGIS Maps SDK for JavaScript 4.26StreamLayerView 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'shighlightOptions
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 };
- The
-
spatialReferenceSupported
InheritedPropertyspatialReferenceSupported Booleanreadonly
Inherited from LayerViewSince: ArcGIS Maps SDK for JavaScript 4.23LayerView 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
-
updating
InheritedPropertyupdating 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);
-
Inherited from LayerView
Since: ArcGIS Maps SDK for JavaScript 4.28LayerView since 4.0, view added at 4.28. -
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
InheritedPropertyvisible Boolean
Inherited from LayerView -
When
true
, the layer is visible in the view. Value of this property is inherited from thelayer.visible
unless the developer overrides it. ThelayerView.visible
will take precedence overlayer.visible
if both properties are set.- Default Value:true
-
visibleAtCurrentScale
InheritedPropertyvisibleAtCurrentScale Booleanreadonly
Inherited from LayerViewSince: ArcGIS Maps SDK for JavaScript 4.30LayerView since 4.0, visibleAtCurrentScale added at 4.30. -
When
true
, the layer is visible in the view at the current scale. This applies to layers that haveminScale
andmaxScale
properties set.Known Limitations
- This property is not supported in 3D SceneView tiled layers.
- Default Value:true
- See also
-
visibleAtCurrentTimeExtent
InheritedPropertyvisibleAtCurrentTimeExtent Booleanreadonly
Inherited from LayerViewSince: ArcGIS Maps SDK for JavaScript 4.30LayerView since 4.0, visibleAtCurrentTimeExtent added at 4.30. -
When
true
, the layer is visible in the view's timeExtent. This applies to layers that have a visibilityTimeExtent.- Default Value:true
- See also
Method Overview
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 | ||
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 | ||
Emits an event on the instance. | StreamLayerView | ||
Indicates whether there is an event listener on the instance that matches the provided event name. | StreamLayerView | ||
Returns true if a named group of handles exist. | Accessor | ||
Highlights the given feature(s) in a layer view. | StreamLayerView | ||
| LayerView | ||
| LayerView | ||
| LayerView | ||
Registers an event handler on the instance. | StreamLayerView | ||
Pauses the connection and stops new observations from being applied until resume() is called. | StreamLayerView | ||
Executes a Query against features available for drawing in the layerView and returns the Extent of features that satisfy the query. | StreamLayerView | ||
Executes a Query against features available for drawing in the layerView and returns the number of features that satisfy the query. | StreamLayerView | ||
Executes a Query against features available for drawing in the layerView and returns a FeatureSet. | StreamLayerView | ||
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 | StreamLayerView | ||
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 | ||
| LayerView |
Method Details
-
Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25Accessor 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();
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.
-
Since: ArcGIS Maps SDK for JavaScript 4.29StreamLayerView 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
createQuery(){Query}
Since: ArcGIS Maps SDK for JavaScript 4.27StreamLayerView 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 totrue
. 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.ReturnsType Description Query The query object Exampleconst query = streamLayerView.createQuery(); query.where = "status = 'in progress'"; csvLayerView.queryFeatures(query).then(function(results) { console.log(results); }) .catch(function(error) { console.log(error); });
-
Since: ArcGIS Maps SDK for JavaScript 4.29StreamLayerView 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
-
hasHandles
InheritedMethodhasHandles(groupKey){Boolean}
Inherited from AccessorSince: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, hasHandles added at 4.25. -
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"); }
-
highlight
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:
- At version 4.23, the
highlight()
method was added to ImageryLayerView and it is only supported in 2D MapView.
ParameterReturnsType 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); }); } }); });
- At version 4.23, the
-
isFulfilled
InheritedMethodisFulfilled(){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.ReturnsType Description Boolean Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected).
-
isRejected
InheritedMethodisRejected(){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.ReturnsType Description Boolean Indicates whether creating an instance of the class has been rejected.
-
isResolved
InheritedMethodisResolved(){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.ReturnsType Description Boolean Indicates whether creating an instance of the class has been resolved.
-
on
on(type, listener){Object}
-
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); });
-
Since: ArcGIS Maps SDK for JavaScript 4.26StreamLayerView 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 frompaused
todisconnected
. Subsequent use of the connect() method will then change the connectionStatus toconnected
.- See also
-
Since: ArcGIS Maps SDK for JavaScript 4.9StreamLayerView 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
Parametersoptional Autocasts from ObjectSpecifies 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 ObjectoptionalAn object with the following properties.
Specificationsignal 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.ReturnsType 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. Examplelet 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
-
Since: ArcGIS Maps SDK for JavaScript 4.9StreamLayerView 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
Parametersoptional Autocasts from ObjectSpecifies 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 ObjectoptionalAn object with the following properties.
Specificationsignal 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.ReturnsExamplesview.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
queryFeatures(query, options){Promise<FeatureSet>}
Since: ArcGIS Maps SDK for JavaScript 4.9StreamLayerView 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
Parametersoptional Autocasts from ObjectSpecifies 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 ObjectoptionalAn object with the following properties.
Specificationsignal 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.ReturnsType Description Promise<FeatureSet> When resolved, a FeatureSet containing an array of graphic features is returned. Examplesconst 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
queryLatestObservations(query, options){Promise<FeatureSet>}
Since: ArcGIS Maps SDK for JavaScript 4.9StreamLayerView 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
Parametersoptional Autocasts from ObjectSpecifies 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 ObjectoptionalAn object with the following properties.
Specificationsignal 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.ReturnsType Description Promise<FeatureSet> When resolved, returns the FeatureSet that satisfy the input query. Examplelet 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
-
Since: ArcGIS Maps SDK for JavaScript 4.9StreamLayerView 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
Parametersoptional Autocasts from ObjectSpecifies 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 ObjectoptionalAn object with the following properties.
Specificationsignal 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.ReturnsExamplesview.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 });
-
Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, removeHandles added at 4.25. -
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");
-
Since: ArcGIS Maps SDK for JavaScript 4.26StreamLayerView 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 theconnectionStatus
is set todisconnected
, invoking this method will have no impact.- See also
-
when
InheritedMethodwhen(callback, errback){Promise}
Inherited from LayerViewSince: ArcGIS Maps SDK for JavaScript 4.6LayerView 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: 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 });
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
-
Fires when the layer view receives features. The event payload contains the attributes and geometry of a feature received from the stream service.
-
Since: ArcGIS Maps SDK for JavaScript 4.26StreamLayerView 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.
-
Since: ArcGIS Maps SDK for JavaScript 4.17StreamLayerView 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.