StreamLayer
require(["esri/layers/StreamLayer"], function(StreamLayer) { /* code goes here */ });esri/layers/StreamLayerThe stream layer extends the feature layer to add the ability to connect to a stream of data using HTML5 WebSockets. It connects to a server that emits geographic features continuously. While the feature layer is used to map relatively static data, the stream layer is suitable when you would like to map dynamic streams of data that are unbounded and continuous. When a stream layer is added to a map, users are able to see real-time updates pushed out by the server.
A real-time-enabled data server is required to use this class. The ArcGIS Geoevent Extension for Server is a tool you may use to set up and configure your data stream. In addition, version 10.3 (and above) of ArcGIS GeoEvent Extension for Server exposes stream services. To learn more about this, please see the Stream Services documentation.
The number of features coming from a real-time feed can overload the browser and make the browser unresponsive. Use the purgeOptions construction option to define rules that specify how to remove data when new messages are received and the layer is refreshed.
WebSockets are a feature of HTML5. Most browsers are supporting WebSockets in recent versions. However, they are not supported by all versions of all browsers. To get more information about WebSockets and to test if a browser supports WebSockets, visit WebSocket.org.
Constructors
- new StreamLayer(properties)
- Parameter:properties ObjectoptionalSee the properties for a list of all the properties that may be passed into the constructor. Example:var streamLayer = new StreamLayer({ url: "https://geoeventsample3.esri.com:6080/arcgis/rest/services/SeattleBus/StreamServer", purgeOptions: { displayCount: 1000 } });
Property Overview
| Name | Type | Summary | Class | |
|---|---|---|---|---|
| Object | Describes the layer's supported capabilities.more details | more details | FeatureLayer | |
| String | The name of the class.more details | more details | Accessor | |
| String | The SQL where clause used to filter features on the client.more details | more details | StreamLayer | |
| Object | Specifies how features are placed on the vertical axis (z).more details | more details | FeatureLayer | |
| FeatureReductionSelection | Configures the method for reducing the number of point features in the view.more details | more details | StreamLayer | |
| FieldsIndex | A convenient property that can be used to make case-insensitive lookups for a field by name.more details | more details | FeatureLayer | |
| Extent | An extent object used to filter features.more details | more details | StreamLayer | |
| String | The geometry type of features in the layer.more details | more details | StreamLayer | |
| String | The unique ID assigned to the layer.more details | more details | Layer | |
| LabelClass[] | The label definition for this layer, specified as an array of LabelClass.more details | more details | StreamLayer | |
| Boolean | Indicates whether to display labels for this layer.more details | more details | StreamLayer | |
| Boolean | Indicates whether the layer will be included in the legend.more details | more details | FeatureLayer | |
| String | Indicates how the layer should display in the LayerList widget.more details | more details | Layer | |
| Boolean | Indicates whether the layer's resources have loaded.more details | more details | Layer | |
| Error | The Error object returned if an error occurred while loading.more details | more details | Layer | |
| String | Represents the status of a load operation.more details | more details | Layer | |
| Object[] | A list of warnings which occurred while loading.more details | more details | Layer | |
| Number | Maximum number of features to show per trackId.more details | more details | StreamLayer | |
| Number | The maximum scale (most zoomed in) at which the layer is visible in the view.more details | more details | FeatureLayer | |
| Number | The minimum scale (most zoomed out) at which the layer is visible in the view.more details | more details | FeatureLayer | |
| String | The name of an  | more details | StreamLayer | |
| Number | The opacity of the layer.more details | more details | Layer | |
| Boolean | Indicates whether to display popups when features in the layer are clicked.more details | more details | FeatureLayer | |
| PopupTemplate | The popup template for the layer.more details | more details | FeatureLayer | |
| Object | Options for purging stale features.more details | more details | StreamLayer | |
| Renderer | The renderer assigned to the layer.more details | more details | FeatureLayer | |
| Boolean | Apply perspective scaling to screen-size point symbols in a SceneView.more details | more details | FeatureLayer | |
| Object | The stream service's metadata JSON exposed by the ArcGIS REST API.more details | more details | StreamLayer | |
| SpatialReference | The spatial reference of the layer.more details | more details | FeatureLayer | |
| TimeExtent | The layer's time extent.more details | more details | FeatureLayer | |
| TimeInfo | TimeInfo provides information such as date fields that store start and end time for each feature and the fullTimeExtent for the layer.more details | more details | FeatureLayer | |
| TimeInterval | A temporary offset of the time data based on a certain TimeInterval.more details | more details | FeatureLayer | |
| String | The title of the layer used to identify it in places such as the Legend and LayerList widgets.more details | more details | FeatureLayer | |
| String | For StreamLayer the type is always "stream". more details | more details | StreamLayer | |
| String | The URL of the stream service.more details | more details | StreamLayer | |
| Boolean | Determines if the layer will update its temporal data based on the view's current timeExtent.more details | more details | FeatureLayer | |
| Number | The version of ArcGIS Server in which the layer is published.more details | more details | FeatureLayer | |
| Boolean | Indicates if the layer is visible in the View.more details | more details | Layer | 
Property Details
- Describes the layer's supported capabilities. - Properties:
- attachment ObjectDescribes what attachment capabilities are enabled on the layer. - Specification:
- supportsName BooleanIndicates if the attachments can be queried by their names. supportsSize BooleanIndicates if the attachments can be queried by their sizes. supportsContentType BooleanIndicates if the attachments can be queried by their content types. supportsKeywords BooleanIndicates if the attachments can be queried by their keywords. supportsExifInfo BooleanIndicates if the attachment queries support exifInfo.
 data ObjectDescribes characteristics of the data in the layer. - Specification:
- isVersioned BooleanIndicates if the feature service is versioned. supportsAttachment BooleanIndicates if the attachment is enabled on the layer. supportsM BooleanIndicates if the features in the layer support M values. Requires ArcGIS Server service 10.1 or greater. supportsZ BooleanIndicates if the features in the layer support Z values. Requires ArcGIS Server service 10.1 or greater. See elevationInfo for details regarding placement and rendering of features with z-values in 3D SceneViews. 
 editing ObjectDescribes editing capabilities that can be performed on the features in the layer via applyEdits(). - Specification:
- supportsDeleteByAnonymous BooleanIndicates if anonymous users can delete features created by others. supportsDeleteByOthers BooleanIndicates if logged in users can delete features created by others. supportsGeometryUpdate BooleanIndicates if the geometry of the features in the layer can be edited. supportsGlobalId BooleanIndicates if the globalIdvalues provided by the client are used in applyEdits.supportsRollbackOnFailure BooleanIndicates if the rollbackOnFailureEnabledparameter can be set totrueorfalsewhen editing features.supportsUpdateByAnonymous BooleanIndicates if anonymous users can update features created by others. supportsUpdateByOthers BooleanIndicates if logged in users can update features created by others. supportsUpdateWithoutM BooleanIndicates if m-valuesmust be provided when updating features.supportsUploadWithItemId BooleanIndicates if the layer supports uploading attachments by UploadId. 
 metadata ObjectDescribes the metadata contained on features in the layer. - Specification:
- supportsAdvancedFieldProperties BooleanIndicates whether to provide a user-defined field description. See Describe attribute fields for additional information. 
 operations ObjectDescribes operations that can be performed on features in the layer. - Specification:
- supportsAdd BooleanIndicates if new features can be added to the layer. supportsDelete BooleanIndicates if features can be deleted from the layer. supportsUpdate BooleanIndicates if features in the layer can be updated. supportsEditing BooleanIndicates if features in the layer can be edited. Use supportsAdd,supportsUpdateandsupportsDeleteto determine which editing operations are supported.supportsCalculate BooleanIndicates if values of one or more field values in the layer can be updated. See the Calculate REST operation document for more information. supportsQuery BooleanIndicates if features in the layer can be queried. supportsQueryAttachments BooleanIndicates if the layer supports REST API queryAttachments operation, which is supported with hosted feature services at version 10.5 and greater. If false, queryAttachments() method can only return attachments for one feature at a time. Iftrue,queryAttachments()can return attachments for array of objectIds.supportsValidateSql BooleanIndicates if the layer supports a SQL-92 expression or where clause. This operation is only supported in ArcGIS Online hosted feature services. supportsResizeAttachments BooleanIndicates if resized attachments are supported in the feature layer. This is useful for showing thumbnails in Popups. 
 query ObjectDescribes query operations that can be performed on features in the layer. - Specification:
- maxRecordCount NumberThe maximum number of records that will be returned for a given query. supportsCentroid BooleanIndicates if the geometry centroid associated with each polygon feature can be returned. This operation is only supported in ArcGIS Online hosted feature services. supportsDistance BooleanIndicates if the layer's query operation supports a buffer distance for input geometries. supportsDistinct BooleanIndicates if the layer supports queries for distinct values based on fields specified in the outFields. supportsDisjointSpatialRelationship BooleanIndicates if the query operation supports disjointspatial relationship. This is valid only for hosted feature services.supportsCacheHint BooleanIndicates if the query operation supports a cache hint. This is valid only for hosted feature services. supportsExtent BooleanIndicates if the layer's query response includes the extent of features. At 10.3, this option is only available for hosted feature services. At 10.3.1, it is available for hosted and non-hosted feature services. supportsGeometryProperties BooleanIndicates if the layer's query response contains geometry attributes, including shape area and length attributes. This operation is supported in ArcGIS Online hosted feature services created since December 2016 and ArcGIS Enterprise feature services since version 10.7. supportsHavingClause BooleanIndicates if the layer supports the having clause on the service. Requires an ArcGIS Server service 10.6.1 or greater. supportsOrderBy BooleanIndicates if features returned in the query response can be ordered by one or more fields. Requires an ArcGIS Server service 10.3 or greater. supportsPagination BooleanIndicates if the query response supports pagination. Requires an ArcGIS Server service 10.3 or greater. supportsQueryGeometry BooleanIndicates if the query response includes the query geometry. This is valid only for hosted feature services. supportsQuantization BooleanIndicates if the query operation supports the projection of geometries onto a virtual grid. Requires an ArcGIS Server service 10.6.1 or greater. supportsQuantizationEditMode BooleanIndicates if the query operation supports quantization designed to be used in edit mode (highest resolution at the given spatial reference). Requires an ArcGIS Server service 10.6.1 or greater. supportsResultType BooleanIndicates if the number of features returned by the query operation can be controlled. supportsSqlExpression BooleanIndicates if the query operation supports SQL expressions. supportsStandardizedQueriesOnly BooleanIndicates if the query operation supports using standardized queries. Learn more about standardized queries here. supportsStatistics BooleanIndicates if the layer supports field-based statistical functions. Requires ArcGIS Server service 10.1 or greater. supportsHistoricMoment BooleanIndicates if the layer supports historic moment query. Requires ArcGIS Server service 10.5 or greater. 
 queryRelated ObjectIndicates if the layer's query operation supports querying features or records related to features in the layer. - Specification:
- supportsCount BooleanIndicates if the layer's query response includes the number of features or records related to features in the layer. supportsOrderBy BooleanIndicates if the related features or records returned in the query response can be ordered by one or more fields. Requires ArcGIS Server service 10.3 or greater. supportsPagination BooleanIndicates if the query response supports pagination for related features or records. Requires ArcGIS Server service 10.3 or greater. 
 
 Example:- // Once the layer loads, check if the // supportsAdd operations is enabled on the layer featureLayer.when(function(){ if (featureLayer.capabilities.operations.supportsAdd) { // if new features can be created in the layer // set up the UI for editing setupEditing(); } });
- Since: ArcGIS API for JavaScript 4.7
- The name of the class. The declared class name is formatted as - esri.folder.className.
- definitionExpression String
- The SQL where clause used to filter features on the client. 
- 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 StringDefines 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 featureExpressionInfois defined, the result of the expression is used instead of the geometry’s z-value.relative-to-groundis the default value for Point geometries rendered with IconSymbol3DLayers.absolute-height Features are placed at an absolute elevation (z-value) above sea level. This z-value is determined by the geometry's z-value (if present). If featureExpressionInfois 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 istrue.relative-to-scene Features are aligned to extruded polygons and 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 featureExpressionInfois added to the 3D Object/terrain surface elevation. In this mode z-values are ignored.Possible Values:"on-the-ground"|"relative-to-ground"|"absolute-height"|"relative-to-scene" optionaloffset NumberAn elevation offset, which is added to the vertical position of the feature. If unitis not defined, the offset is inmeters. Whenmode = "on-the-ground", this property has no effect.optionalfeatureExpressionInfo ObjectThis object contains information about setting a custom z-value on the feature. - Specification:
- optionalexpression StringAn Arcade expression evaluating to a number that determines the z-value of the feature. If the geometry has z-values, they will be ignored and featureExpressionInfowill be used to calculate the vertical position of the feature. Whenmode = "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.
 optionalunit StringThe unit for featureExpressionInfoandoffsetvalues. It doesn't apply to z-values.
 
- featureReduction FeatureReductionSelectionautocastSince: ArcGIS API for JavaScript 4.4
- Configures the method for reducing the number of point features in the view. By default this property is - null, which indicates the layer view should draw every feature.- StreamLayer supports one type feature reduction: - selection. Selection only applies to points in a SceneView and involves thinning overlapping features so no features intersect on screen.- See also:
 Example:- // thins features in the view layer.featureReduction = { type: "selection" };
- Since: ArcGIS API for JavaScript 4.12
- A convenient property that can be used to make case-insensitive lookups for a field by name. It can also provide a list of the date fields in a layer. Example:- // lookup a field by name. name is case-insensitive const field = layer.fieldsIndex.get("SoMeFiEld"); if (field) { console.log(field.name); // SomeField }
- geometryDefinition Extent
- An extent object used to filter features. Only features intersecting the extent are displayed in the view. 
- geometryType Stringreadonly
- The geometry type of features in the layer. - Possible Values:"point"|"multipoint"|"polyline"|"polygon" 
- The unique ID assigned to the layer. If not set by the developer, it is automatically generated when the layer is loaded. 
- labelingInfo LabelClass[]autocast
- 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. - Multiple Label classes with different - whereclauses 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:
 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 ];
- labelsVisible Boolean
- Indicates whether to display labels for this layer. If - true, labels will appear as defined in the labelingInfo property.- Default Value:true
 
- Indicates whether the layer will be included in the legend. - Default Value:true
 
- 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
 
- Indicates whether the layer's resources have loaded. When - true, all the properties of the object can be accessed.- Default Value:false
 
- The Error object returned if an error occurred while loading. - Default Value:null
 
- 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
 
- A list of warnings which occurred while loading. 
- maximumTrackPoints Number
- Maximum number of features to show per trackId. If - trackIdis not configured on the GeoEvent Service, the- maximumTrackPointsproperty will have no effect and an error will be logged in the console.
- 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 - 0means the layer does not have a maximum scale. The maxScale value should always be smaller than the minScale value, and greater than or equal to the service specification.- 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;
- 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 - 0means the layer does not have a minimum scale. The minScale value should always be larger than the maxScale value, and lesser than or equal to the service specification.- 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;
- objectIdField String
- The name of an - oidfield containing a unique value or identifier for each feature in the layer.- See also:
 
- The opacity of the layer. This value can range between - 1and- 0, where- 0is 100 percent transparent and- 1is completely opaque.- Default Value:1
 Example:- // Makes the layer 50% transparent layer.opacity = 0.5;
- Indicates whether to display popups when features in the layer are clicked. The layer needs to have a popupTemplate to define what information should be displayed in the popup. Alternatively, a default popup template may be automatically used if Popup.defaultPopupTemplateEnabled is set to - true.- Default Value:true
- See also:
 
- The popup template for the layer. When set on the layer, the - popupTemplateallows 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.- A default popup template is automatically used if no - popupTemplatehas been defined when Popup.defaultPopupTemplateEnabled is set to- true.- See also:
 
- purgeOptions Object
- Options for purging stale features. Use these options to avoid overloading the browser with graphics. 
- 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:
 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" } } };
- 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:
 
- sourceJSON ObjectSince: ArcGIS API for JavaScript 4.13
- The stream service's metadata JSON exposed by the ArcGIS REST API. While most commonly used properties are exposed on the StreamLayer class directly, this property gives access to all information returned by the stream service. This property is useful if working in an application built using an older version of the API which requires access to stream service properties from a more recent version. 
- 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. 
- Since: ArcGIS API for JavaScript 4.14
- The layer's time extent. When the layer's useViewTime is - false, the layer instructs the view to show data from the layer based on this time extent. If the- useViewTimeis- true, then this property has no effect on the layer, because the layer will show the data within the view's timeExtent property.- Default Value:null
 Examples:- if (!layer.useViewTime) { if (layer.timeExtent) { console.log("Current timeExtent:", layer.timeExtent.start, " - ", layer.timeExtent.end} } else { console.log("The layer will display data within the view's timeExtent."); console.log("Current view.timeExtent:", view.timeExtent.start, " - ", view.timeExtent.end} } }- // set the timeExtent on the layer and useViewTime false // In this case, the layer will honor its timeExtent and ignore // the view's timeExtent const layer = new ImageryLayer({ url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/ScientificData/SeaTemperature/ImageServer", timeExtent: { start: new Date(2014, 4, 18), end: new Date(2014, 4, 19) }, useViewTime: false });
- Since: ArcGIS API for JavaScript 4.11
- TimeInfo provides information such as date fields that store start and end time for each feature and the fullTimeExtent for the layer. The - timeInfoproperty, along with its- startFieldand- endFieldproperties, must be set at the time of layer initialization if it is being set for a GeoJSONLayer, CSVLayer or FeatureLayer initialized from client-side features. The fullTimeExtent for- timeInfois automatically calculated based on its- startFieldand- endFieldproperties. The timeInfo parameters cannot be changed after the layer is loaded.- Default Value:null
 Example:- // create geojson layer from usgs earthquakes geojson feed const geojsonLayer = new GeoJSONLayer({ url: "https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson", copyright: "USGS Earthquakes", fields: [ { "name": "mag", "type": "double" }, { "name": "place", "type": "string" }, { "name": "time", "type": "date" }, // date field { "name": "depth", "type": "double" } ], // timeInfo can be used to do temporal queries // set the startField and endField. // timeExtent is automatically calculated from the // the start and end date fields timeInfo: { startField: "time" } });
- Since: ArcGIS API for JavaScript 4.14
- A temporary offset of the time data based on a certain TimeInterval. This allows users to overlay features from two or more time-aware layers with different time extents. For example, if a layer has data recorded for the year 1970, an offset value of 2 years would temporarily shift the data to 1972. You can then overlay this data with data recorded in 1972. A time offset can be used for display purposes only. The query and selection are not affected by the offset. - Default Value:null
 Example:- // Offset a CSV Layer containing hurricanes from 2015 so that they appear in 2019 (+4 years). var layer = new CSVLayer({ url: `hurricanes-and-storms-2015.csv`, timeOffset: { value: 4, unit: "years" }, timeInfo: { startField: "ISO_time" }, renderer: { type: "simple", symbol: { type: "simple-marker", size: 6, color: "red", outline: { width: 0.5, color: "black" } } } });
- 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. 
- type Stringreadonly
- For StreamLayer the type is always "stream". 
- url String
- The URL of the stream service. This is set in the - urlparameter of the constructor.Example:- var layer = new StreamLayer({ url: "https://geoeventsample3.esri.com:6443/arcgis/rest/services/SeattleBus/StreamServer" });
- Since: ArcGIS API for JavaScript 4.14
- Determines if the layer will update its temporal data based on the view's current timeExtent. When - false, the layer will display its temporal data based on the layer's timeExtent, regardless of changes to the view.- Default Value:true
 Example:- if (featureLayer.useViewTime) { console.log("Displaying data between:", view.timeExtent.start, " - ", view.timeExtent.end); }
- 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);
- 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 | |
|---|---|---|---|---|
| Cancels a load() operation if it is already in progress.more details | more details | Layer | ||
| Promise<LayerView> | 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.more details | more details | Layer | |
| PopupTemplate | Creates a popup template for the layer, populated with all the fields of the layer.more details | more details | FeatureLayer | |
| Boolean | Emits an event on the instance.more details | more details | Layer | |
| Field | Returns the Field instance for a field name (case-insensitive).more details | more details | FeatureLayer | |
| Boolean | Indicates whether there is an event listener on the instance that matches the provided event name.more details | more details | Layer | |
| Boolean | 
 | more details | Layer | |
| Boolean | 
 | more details | Layer | |
| Boolean | 
 | more details | Layer | |
| Promise | Loads the resources referenced by this class.more details | more details | Layer | |
| Object | Registers an event handler on the instance.more details | more details | Layer | |
| Promise | 
 | more details | Layer | 
Method Details
- 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. Parameters:view *- The parent view. options Objectoptional- An object specifying additional options. See the object specification table below for the required properties of this object. Specification:signal AbortSignaloptional- A signal to abort the creation of the layerview. Returns:- Type - Description - Promise<LayerView> - Resolves with a LayerView instance. - See also:
 
- Since: ArcGIS API for JavaScript 4.11
- Creates a popup template for the layer, populated with all the fields of the layer. Parameters:Specification:options Objectoptional- Options for creating the popup template. Specification:maximumFields NumberoptionalDefault Value: 75- The maximum number of fields to include in the popup template. - optional - Field types to ignore when creating the popup. By default the - geometry,- blob,- raster,- guidand- xmlfield types are ignored.Returns:- Type - Description - PopupTemplate - The popup template, or - nullif the layer does not have any fields.
- 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 Objectoptional- The event payload. Returns:- Type - Description - Boolean - trueif a listener was notified
- Since: ArcGIS API for JavaScript 4.11
- Returns the Field instance for a field name (case-insensitive). Parameter:fieldName String- Name of the field. Returns:- Type - Description - Field - the matching field or - undefined- See also:
 
- 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()may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected). If it is fulfilled,- truewill be returned.Returns:- Type - Description - Boolean - Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected). 
- isRejected()may be used to verify if creating an instance of the class is rejected. If it is rejected,- truewill be returned.Returns:- Type - Description - Boolean - Indicates whether creating an instance of the class has been rejected. 
- isResolved()may be used to verify if creating an instance of the class is resolved. If it is resolved,- truewill be returned.Returns:- Type - Description - Boolean - Indicates whether creating an instance of the class has been resolved. 
- 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. - It's possible to provide a - signalto stop being interested into a- Loadableinstance load status. When the signal is aborted, the instance does not stop its loading process, only cancelLoad can abort it.Parameter:signal AbortSignaloptional- Signal object that can be used to abort the asynchronous task. The returned promise will be rejected with an Error named - AbortErrorwhen 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 - Resolves when the resources have loaded. 
- Registers an event handler on the instance. Call this method to hook an event with a listener. Parameters:- A event type, or an array of event types, 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(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); });
- 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- callbackfunction and an- errbackfunction. The- callbackexecutes when the instance of the class loads. The- errbackexecutes if the instance of the class fails to load.Parameters:callback Functionoptional- The function to call when the promise resolves. errback Functionoptional- The function to execute when the promise fails. Returns:- Type - Description - Promise - Returns a new promise for the result of - callbackthat 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
| Name | Type | Summary | Class | |
|---|---|---|---|---|
| {view: View,layerView: LayerView} | Fires after the layer's LayerView is created and rendered in a view.more details | more details | 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.more details | more details | Layer | |
| {view: View,layerView: LayerView} | Fires after the layer's LayerView is destroyed and no longer renders in a view.more details | more details | Layer | 
Event Details
- layerview-createinherited
- Fires after the layer's LayerView is created and rendered in a view. - Properties:
- view ViewThe view in which the layerViewwas created.layerView LayerViewThe LayerView rendered in the view representing the layer in layer.
- 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; });
- layerview-create-errorinherited
- Fires when an error emits during the creation of a LayerView after a layer has been added to the map. - Properties:
- view ViewThe view that failed to create a layerview for the layer emitting this event. error ErrorAn error object describing why the layer view failed to create. 
- 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); });