Property Overview

Property Details

connectionErrorErrorreadonly

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

connectionStatusStringreadonly

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

Possible Values: connected | disconnected

declaredClassStringreadonly

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

filterObjectreadonly

Contains the attribute and spatial filters used to filter messages sent to the given layer view by a stream service. To change the filter for only a single layer view, use the updateFilter() method. The layer view's filter is always updated when the updateFilter() method of the associated stream layer instance is called.

Properties:

geometry Extent optional A spatial filter for filtering features. Only features that intersect the given geometry are displayed in the view.

where String optional A SQL where clause used to filter features by attributes.

See also:

• StreamLayer.filter

graphicsCollection

Contains the collection of graphics visible in the layer view for the live stream. Graphics may be removed from the layer view by calling the removeAll() method from Collection.

Example:

// removes all stream layer graphics from view
// new messages add features to the view
view.whenLayerView(streamLayer)
  .then(function(layerView){
    layer.graphics.removeAll();
  });

Method Overview

Method Details

connect(){Promise}

Opens a web socket connection with the stream service to start receiving messages. This is called internally when the StreamLayer is added to a view.

Returns:

Type	Description
Promise	The promise is resolved if the connection is successful or rejected with an error if the connection failed

disconnect()

Closes the web socket connection with the stream service. This is called internally when the StreamLayer is removed from a view.

To verify when the connection is closed, watch the connectionStatus property.

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.

highlight(target){Object}

Highlights the given feature(s).

Known Limitations

Currently the highlight method is only supported in a SceneView.

Parameter:

target Graphic | Graphic[] | Number | Number[] 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 or an array.

Returns:

Type	Description
Object	Returns a highlight handler with a remove() method that can be called to remove the highlight. Property Type Description remove Function When called, removes the highlight of the selected graphics.

See also:

• SceneView.highlightOptions

• Sample: Highlight point features

Example:

// highlight feature on click
view.on("click", function(event){
 view.hitTest(event).then(function(response){
   if (response.results[0]) {
     var graphic = response.results[0].graphic;
     view.whenLayerView(graphic.layer).then(function(lyrView){
       lyrView.highlight(graphic);
     })
   }
 })
});

on(type, listener){Object}

Registers an event handler on the instance. Call this method to hook an event with a listener. See the Events summary table for a list of listened events.

Parameters:

type String The name of event to listen for.

listener Function The function to call when the event is fired.

Returns:

Type	Description
Object	Returns an event handler with a remove() method that can be called to stop listening for the event. Property Type Description remove Function When called, removes the listener from the event.

See also:

• dojo/on

Example:

view.on("click", function(event){
  // event is the event handle returned after the event fires.
  console.log(event.mapPoint);
});

updateFilter(filter){Promise}

Updates the filter on the StreamLayerView. The filter is updated only on the layer view from which it is called. To update the filter on all layer views generated from a common layer, use the StreamLayer.updateFilter() method. If the input filter object is undefined or null, the spatial and attribute filters are removed.

Parameters:

filter Object Updates the spatial and attribute filters. If null, all filters are cleared. Specification: geometry Extent optional A spatial filter for filtering features. Only features that intersect the given geometry are displayed in the view. If null, the spatial filter is cleared. where String optional A SQL where clause used to filter features by attributes. If null, the attribute filter is cleared.

Returns:

Type	Description
Promise	Resolves to an object that has a filter property, indicating the filter set on the stream service by the layer view. If the filter could not be updated, the promise is rejected with an error that explains why the filter failed to update.

See also:

• StreamLayer.updateFilter()

Examples:

// updates the spatial filter based on the current view's extent
// and removes the attribute filter
layerView.updateFilter({
  geometry: mapView.extent,
  where: null
});

// updates the attribute filter to only display features whose
// route ID is 110
layerView.updateFilter({
  where: "ROUTE_ID = 110"
});

// clears all filters from the layer
layerView.updateFilter(null);

Event Overview

Event Details

data-received

Fires when the layer view receives data. The event object contains the message properties received from the stream service.