Property Overview

Property Details

declaredClassStringreadonly inherited

Since: ArcGIS API for JavaScript 4.7

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

definitionExpressionString

Deprecated

• since version 4.3.

The SQL where clause used to filter features on the client. Use StreamLayer.filter.where when creating the service or StreamLayer.updateFilter() when changing the attribute filter instead of this property.

elevationInfoObject inherited

Specifies how features are placed on the vertical axis (z). This property may only be used in a SceneView. See the ElevationInfo sample for an example of how this property may be used.

Properties:

mode String Defines how the feature is placed with respect to the terrain surface. If the geometry consists of multiple points (e.g. lines or polygons), the elevation is evaluated separately for each point. See the table below for a list of possible values. Mode Description on-the-ground Features are draped on the terrain surface. This is the default value for features with Polyline or Polygon geometries and features with Point geometries rendered with ObjectSymbol3DLayers. relative-to-ground Features are placed at an elevation relative to the terrain surface. The feature's elevation is determined by summing up the terrain elevation and the geometry's z-value (if present). If featureExpressionInfo is defined, the result of the expression is used instead of the geometry’s z-value. relative-to-ground is the default value for Point geometries rendered with IconSymbol3DLayers. absolute-height Features are placed at an absolute height above sea level. This height is determined by the geometry's z-value (if present). If featureExpressionInfo is defined, the result of the expression is used instead of the geometry’s z-value. This mode doesn't take the elevation of the terrain into account. This is the default value of features with any geometry type where hasZ is true. relative-to-scene Features are aligned to buildings and other objects part of 3D Object SceneLayers or IntegratedMeshLayers, depending on which has higher elevation. If the feature is not directly above a building or any other feature, it is aligned to the terrain surface elevation. If defined, the result of featureExpressionInfo is added to the 3D Object/terrain surface elevation. In this mode z-values are ignored.

offset Number optional An elevation offset, which is added to the vertical position of the feature. If unit is not defined, the offset is in meters. When mode = "on-the-ground", this property has no effect.

featureExpressionInfo Object optional This object contains information about setting a custom height on the feature. If this property is set, then z values are not considered for calculating feature height. Specification: expression String optional An Arcade expression evaluating to a number that determines the height of the feature. If the geometry has z-values, they will be ignored and only featureExpressionInfo is used to calculate the vertical position of the feature. When mode = "on-the-ground", this property has no effect. For line and polygon geometries the result of the expression is the same for all vertices of a feature.

unit String optional The unit for featureExpressionInfo and offset values. It doesn't apply to z-values. Possible Values: feet | meters | kilometers | miles | us-feet | yards

featureReductionObject inherited

Since: ArcGIS API for JavaScript 4.4

Configures the method for decluttering overlapping features in the view. If this property is not set (or set to null), every feature is drawn individually.

Currently this property is only supported in 3D SceneViews for point features with non-draped Icons or Text symbol layers.

Property:

type String Type of the decluttering method. The only supported type at the moment is "selection". In this method, some of the overlapping features are hidden such that none of the remaining features intersect on screen. Label deconfliction also respects this option and hides labels that would overlap with the features of this layer.

See also:

• Sample: Point styles for cities

Example:

layer.featureReduction = {
  type: "selection"
};

filterObjectreadonly

Since: ArcGIS API for JavaScript 4.3

Contains the attribute and spatial filters used to filter messages sent to the client by a Stream Service. This property can be set in the constructor but is read-only after the layer is created. To change the filter after the layer is created, use the updateFilter() method.

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:

• StreamLayerView.filter

Example:

var layer = new StreamLayer({
  url: streamLayerUrl,
  // only displays features within the view's visible extent
  // and features whose route id is 20
  filter: {
    geometry: view.extent.clone(),
    where: "route_id = 20"
  }
});

geometryDefinitionExtent

Deprecated

• since version 4.3.

An extent object used to filter features. Only features intersecting the extent are displayed in the view. Instead of using this property, use StreamLayer.filter.geometry when creating the service or StreamLayer.updateFilter() when changing the spatial filter.

geometryTypeString

The geometry type of features in the layer. For StreamLayer, the geometryType is always point.

idString inherited

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

labelingInfoLabelClass[]autocast

Autocasts from Object[]

The label definition for this layer, specified as an array of LabelClass. Use this property to specify labeling properties for the layer such as label expression, placement, and size.

For labels to display in the view, the labelsVisible property of this layer must be set to true.

Multiple Label classes with different where clauses can be used to define several labels with varying styles on the same feature. Likewise, multiple label classes may be used to label different types of features (for example blue labels for boats and green labels for trucks).

Known Limitations

• Currently only one LabelClass is supported in 3D SceneViews.

See also:

• Sample: Flat vs. volumetric 3D symbol layers

• Sample: Add multiple label classes to a layer

• Sample: Multi-line labels

Example:

const boatLabelClass = new LabelClass({
  labelExpressionInfo: { expression: "$feature.NAME" },
  symbol: {
    type: "label-3d",  // autocasts as new LabelSymbol3D()
    symbolLayers: [{
      type: "text",  // autocasts as new TextSymbol3DLayer()
      material: { color: [ 49,163,84 ] },
      size: 12  // points
    }]
  }
});

streamLayer.labelingInfo = [ boatLabelClass ];

labelsVisibleBoolean

Indicates whether to display labels for this layer. If true, labels will appear as defined in the labelingInfo property.

Default Value:true

legendEnabledBoolean inherited

Indicates whether the layer will be included in the legend.

Default Value:true

listModeString inherited

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

Value	Description
show	The layer is visible in the table of contents.
hide	The layer is hidden in the table of contents.
hide-children	If the layer is a GroupLayer, hide the children layers from the table of contents.

Default Value:show

loadedBooleanreadonly inherited

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

Default Value:false

loadErrorErrorreadonly inherited

The Error object returned if an error occurred while loading.

Default Value:null

loadStatusStringreadonly inherited

Represents the status of a load operation.

Value	Description
not-loaded	The object's resources have not loaded.
loading	The object's resources are currently loading.
loaded	The object's resources have loaded without errors.
failed	The object's resources failed to load. See loadError for more details.

Default Value:not-loaded

loadWarningsObject[]readonly inherited

A list of warnings which occurred while loading.

maximumTrackPointsNumber

Maximum number of features to show per trackId.

maxScaleNumber inherited

The maximum scale (most zoomed in) at which the layer is visible in the view. If the map is zoomed in beyond this scale, the layer will not be visible. A value of 0 means the layer does not have a maximum scale. The maxScale value should always be smaller than the minScale value.

Default Value:0

Examples:

// The layer will not be visible when the view is zoomed in beyond a scale of 1:1,000
layer.maxScale = 1000;

// The layer's visibility is not restricted to a maximum scale.
layer.maxScale = 0;

minScaleNumber inherited

The minimum scale (most zoomed out) at which the layer is visible in the view. If the map is zoomed out beyond this scale, the layer will not be visible. A value of 0 means the layer does not have a minimum scale. The minScale value should always be larger than the maxScale value.

Default Value:0

Examples:

// The layer will not be visible when the view is zoomed out beyond a scale of 1:3,000,000
layer.minScale = 3000000;

// The layer's visibility is not restricted to a minimum scale.
layer.minScale = 0;

opacityNumber inherited

The opacity of the layer. This value can range between 1 and 0, where 0 is 100 percent transparent and 1 is completely opaque.

Default Value:1

Example:

// Makes the layer 50% transparent
layer.opacity = 0.5;

popupEnabledBoolean inherited

Indicates whether to display popups when features in the layer are clicked.

Default Value:true

popupTemplatePopupTemplateautocast inherited

The popup template for the layer. When set on the layer, the popupTemplate allows users to access attributes and display their values in the view's popup when a feature is selected using text and/or charts. See the PopupTemplate sample for an example of how PopupTemplate interacts with a FeatureLayer.

purgeOptionsObject

Options for purging stale features. Use these options to avoid overloading the browser with graphics.

Properties:

displayCount Number The maximum number of features to display. Excess features are purged from the beginning of the graphics array.

age Number The maximum time in minutes that a feature should be kept. After this time, the feature is removed from the layer.

rendererRendererautocast inherited

The renderer assigned to the layer. The renderer defines how to visualize each feature in the layer. Depending on the renderer type, features may be visualized with the same symbol, or with varying symbols based on the values of provided attribute fields or functions.

However, when creating a FeatureLayer from client-side features, this property must be specified in the layer's constructor along with the source, fields, objectIdField properties.

See also:

• Creating visualizations manually

Example:

// all features in the layer will be visualized with
// a 6pt black marker symbol and a thin, white outline
layer.renderer = {
  type: "simple",  // autocasts as new SimpleRenderer()
  symbol: {
    type: "simple-marker",  // autocasts as new SimpleMarkerSymbol()
    size: 6,
    color: "black",
    outline: {  // autocasts as new SimpleLineSymbol()
      width: 0.5,
      color: "white"
    }
  }
};

screenSizePerspectiveEnabledBoolean inherited

Since: ArcGIS API for JavaScript 4.4

Apply perspective scaling to screen-size point symbols in a SceneView. When true, screen sized objects such as icons, labels or callouts integrate better in the 3D scene by applying a certain perspective projection to the sizing of features. This only applies when using a SceneView.

layer.screenSizePerspectiveEnabled = true

layer.screenSizePerspectiveEnabled = false

Known Limitations

Screen size perspective is currently not optimized for situations where the camera is very near the ground, or for scenes with point features located far from the ground surface. In these cases it may be better to turn off screen size perspective. As screen size perspective changes the size based on distance to the camera, it should be set to false when using size visual variables.

Default Value:true

See also:

• Sample: Point styles for cities

spatialReferenceSpatialReferenceautocast inherited

The spatial reference of the layer. When creating the layer from a url, the spatial reference is read from the service.

When creating a FeatureLayer from client-side features, this property is inferred from the geometries of the features provided in the source property.

titleString inherited

The title of the layer used to identify it in places such as the Legend and LayerList widgets.

When loading a layer by service url, the title is derived from the service name. If the service has several layers, then the title of each layer will be the concatenation of the service name and the layer name. When the layer is loaded from a portal item, the title of the portal item will be used instead. Finally, if a layer is loaded as part of a webmap or a webscene, then the title of the layer as stored in the webmap/webscene will be used.

tokenStringreadonly inherited

Deprecated

• since version 4.8. Will be removed at version 4.10.

Token generated by the token service using the specified userId and password. The recommended approach to pass a token on a layer is to use IdentityManager.registerToken().

typeStringreadonly

For StreamLayer the type is stream.

urlString

The URL of the stream service. This is set in the url parameter of the constructor.

Example:

var layer = new StreamLayer({
 url: "https://geoeventsample3.esri.com:6443/arcgis/rest/services/SeattleBus/StreamServer"
});

versionNumberreadonly inherited

The version of ArcGIS Server in which the layer is published.

Example:

// Prints the version number to the console - e.g. 10.2, 10.3, 10.41, etc.
console.log(layer.version);

visibleBoolean inherited

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

Default Value:true

Example:

// The layer is no longer visible in the view
layer.visible = false;

Method Overview

Method Details

cancelLoad()inherited

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

emit(type, event)inherited

Since: ArcGIS API for JavaScript 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 The event payload.

hasEventListener(type){Boolean}inherited

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

Parameter:

type String The name of the event.

Returns:

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

isFulfilled(){Boolean}inherited

isFulfilled() may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected). If it is fulfilled, true will be returned.

Returns:

Type	Description
Boolean	Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected).

isRejected(){Boolean}inherited

isRejected() may be used to verify if creating an instance of the class is rejected. If it is rejected, true will be returned.

Returns:

Type	Description
Boolean	Indicates whether creating an instance of the class has been rejected.

isResolved(){Boolean}inherited

isResolved() may be used to verify if creating an instance of the class is resolved. If it is resolved, true will be returned.

Returns:

Type	Description
Boolean	Indicates whether creating an instance of the class has been resolved.

load(){Promise}inherited

Loads the resources referenced by this class. This method automatically executes for a View and all of the resources it references in Map if the view is constructed with a map instance.

This method must be called by the developer when accessing a resource that will not be loaded in a View.

Returns:

Type	Description
Promise	Resolves when the resources have loaded.

on(type, listener){Object}inherited

Registers an event handler on the instance. Call this method to hook an event with a listener.

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(filterChanges){Promise<Object>}

Since: ArcGIS API for JavaScript 4.3

Updates the filter on the layer. The filter is updated on all views that contain the layer. If the input filterChanges object is undefined or null, the spatial and attribute filters are removed. To update the filter on a single layer view associated with the layer, use the StreamLayerView.updateFilter() method after getting the layer view object.

Filter changes only apply to incoming features. Features already displayed in the view will be removed automatically.

Parameters:

filterChanges Object Updates the spatial and attribute filters on the layer and all of its associated views. If null, all filters are cleared. Specification: geometry Extent A spatial filter for filtering features. Only features that intersect the given geometry are displayed in the view(s). If null, the spatial filter is cleared. where String A SQL where clause used to filter features by attributes. If null, the attribute filter is cleared.

Returns:

Type	Description
Promise<Object>	Resolves to an object that has an error property if the update was not successful. The object also has a filter property that indicates the filter set on the layer.

See also:

• StreamLayerView.updateFilter()

Examples:

view.whenLayerView(layer)
 .then(function(layerView){

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

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

when(callback, errback){Promise}inherited

Since: ArcGIS API for JavaScript 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 then() in the same way
var 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

{view: View,layerView: LayerView}

{view: View,layerView: LayerView}

Event Details

layerview-createinherited

Fires after the layer's LayerView is created and rendered in a view.

Properties:

view View The view in which the layerView was created.

layerView LayerView The LayerView rendered in the view representing the layer in layer.

See also:

• View.whenLayerView()

Example:

// This function will fire each time a layer view is created for this
// particular view.
layer.on("layerview-create", function(event){
  // The LayerView for the layer that emitted this event
  event.layerView;
});

layerview-destroyinherited

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

Properties:

view View The view in which the layerView was destroyed.

layerView LayerView The destroyed LayerView representing the layer.