require(["esri/widgets/Track/TrackViewModel"], (TrackVM) => { /* code goes here */ });
import TrackVM from "@arcgis/core/widgets/Track/TrackViewModel.js";
esri/widgets/Track/TrackViewModel
Provides the logic for the Track widget, which animates the View to the user's location when clicked and tracks it as the location is updated.
The Track widget is only available in secure contexts, such as HTTPS. Note that localhost is considered "potentially secure" and can be used for easy testing in browsers that support Window.isSecureContext.
For additional information regarding this, visit the ArcGIS blog, Increased web API security in Google Chrome.
let trackWidget = new Track({
viewModel: { // autocasts as new TrackViewModel()
view: view, // attaches the Track to the view
}
};
Constructors
-
new TrackViewModel(properties)
-
Parameterproperties Objectoptional
See the properties for a list of all the properties that may be passed into the constructor.
Property Overview
Name | Type | Summary | Class |
---|---|---|---|
String | The name of the class. more details | Accessor | |
Object | An object used for setting optional position parameters. more details | TrackViewModel | |
Boolean | Indicates whether to navigate the view to the position and scale of the geolocated result. more details | TrackViewModel | |
GoToOverride | This function provides the ability to override either the MapView goTo() or SceneView goTo() methods. more details | TrackViewModel | |
Graphic | The graphic used to show the user's location on the map. more details | TrackViewModel | |
Function | A function that is used as an expression to evaluate geolocation points, and returns a boolean value. more details | TrackViewModel | |
Number | Indicates the scale to set on the view when navigating to the position of the geolocated result, after a location is returned from the track event. more details | TrackViewModel | |
String | The current state of the widget. more details | TrackViewModel | |
Boolean | Indicates whether new positions are being watched. more details | TrackViewModel | |
MapView|SceneView | The view associated with the widget. more details | TrackViewModel |
Property Details
-
Since: ArcGIS Maps SDK for JavaScript 4.7
-
The name of the class. The declared class name is formatted as
esri.folder.className
.
-
geolocationOptions Object
-
An object used for setting optional position parameters. Refer to the Geolocation API Specification for details on using these paramters.
- Default Value:null
Exampleconst track = new Track({ view: view, // Set optional position paramters geolocationOptions: { maximumAge: 0, timeout: 15000, enableHighAccuracy: true } });
-
goToLocationEnabled Boolean
-
Indicates whether to navigate the view to the position and scale of the geolocated result.
- Default Value:true
-
goToOverride GoToOverrideSince: ArcGIS Maps SDK for JavaScript 4.8
-
This function provides the ability to override either the MapView goTo() or SceneView goTo() methods.
Example// The following snippet uses the Search widget but can be applied to any // widgets that support the goToOverride property. search.goToOverride = function(view, goToParams) { goToParams.options.duration = updatedDuration; return view.goTo(goToParams.target, goToParams.options); };
-
graphic Graphic
-
The graphic used to show the user's location on the map.
Exampleconst trackWidget = new Track({ // Assign the track widget to a view view: view, // Overwrite the default symbol used for the // graphic placed at the location of the user graphic: new Graphic ({ symbol: { // autocasts as new SimpleMarkerSymbol() type: "simple-marker", size: "12px", color: "blue", // autocasts as new SimpleLineSymbol() outline: { color: "#efefef", width: "1.5px" } } }) });
-
positionFilterFunction FunctionSince: ArcGIS Maps SDK for JavaScript 4.27
-
A function that is used as an expression to evaluate geolocation points, and returns a boolean value. If the function returns
true
, the widget will draw a graphic and navigate to the position. The widget will ignorefalse
values and not draw a graphic and not navigate to the position.Example use cases include smoothing out geolocation anomalies and geofencing.
- Default Value:null
Example// Exclude locations that full outside an extent. track.viewModel.positionFilterFunction = (value) => { const { longitude, latitude } = value.position.coords; const myLocation = new Point({ longitude, latitude }); const geofenceExtent = new Extent({ // whatever }); return geometryEngine.within(myLocation, geofenceExtent); };
-
scale NumberSince: ArcGIS Maps SDK for JavaScript 4.7
-
Indicates the scale to set on the view when navigating to the position of the geolocated result, after a location is returned from the track event.
By default, the view will navigate to a scale of
2500
for 3D and4514
for 2D. To override the default in 2D, set thescale
property and also set snapToZoom tofalse
. For 2D views the value should be within the effectiveMinScale and effectiveMaxScale.- Default Value:null
-
state Stringreadonly
-
The current state of the widget.
Possible Values:"disabled"|"ready"|"tracking"|"waiting"
- Default Value:disabled
-
tracking Booleanreadonly
-
Indicates whether new positions are being watched.
- Default Value:false
-
The view associated with the widget.
Method Overview
Name | Return Type | Summary | Class |
---|---|---|---|
Adds one or more handles which are to be tied to the lifecycle of the object. more details | Accessor | ||
Boolean | Emits an event on the instance. more details | TrackViewModel | |
Boolean | Indicates whether there is an event listener on the instance that matches the provided event name. more details | TrackViewModel | |
Boolean | Returns true if a named group of handles exist. more details | Accessor | |
Object | Registers an event handler on the instance. more details | TrackViewModel | |
Removes a group of handles owned by the object. more details | Accessor | ||
When executed, tracking starts at the user's location. more details | TrackViewModel | ||
Stops tracking the user's location when executed. more details | TrackViewModel |
Method Details
-
addHandles(handleOrHandles, groupKey)inheritedSince: ArcGIS Maps SDK for JavaScript 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.
-
emit(type, event){Boolean}Since: ArcGIS Maps SDK for JavaScript 4.5
-
Emits an event on the instance. This method should only be used when creating subclasses of this class.
Parameterstype StringThe name of the event.
event ObjectoptionalThe event payload.
ReturnsType Description Boolean true
if a listener was notified
-
hasEventListener(type){Boolean}
-
Indicates whether there is an event listener on the instance that matches the provided event name.
Parametertype StringThe name of the event.
ReturnsType Description Boolean Returns true if the class supports the input event.
-
Since: ArcGIS Maps SDK for JavaScript 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"); }
-
on(type, listener){Object}
-
Registers an event handler on the instance. Call this method to hook an event with a listener.
ParametersAn event or an array of events to listen for.
listener FunctionThe function to call when the event fires.
ReturnsType 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); });
-
removeHandles(groupKey)inheritedSince: ArcGIS Maps SDK for JavaScript 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");
-
start()
-
When executed, tracking starts at the user's location.
-
stop()
-
Stops tracking the user's location when executed.
Event Overview
Name | Type | Summary | Class |
---|---|---|---|
{position: Object} |
Fires after the start() method is called and a position is found. more details |
TrackViewModel | |
{error: Error} |
Fires after the start() method is called and an error is returned. more details |
TrackViewModel |
Event Details
-
track
-
Fires after the start() method is called and a position is found.
- Property
-
position Object
Geoposition returned from the Geolocation API.