HomeViewModel | API Reference | ArcGIS Maps SDK for JavaScript 4.32

Provides the logic for the Home component and Home widget that animates the View to its initial Viewpoint or a previously defined viewpoint.

See also

Home component
Home widget - Deprecated since 4.32. Use the Home component instead.
Programming patterns: Widget viewModel pattern

Example

let homeWidget = new Home({
  viewModel: {  // autocasts as new HomeViewModel()
    view: view
  }
}, "homediv");  // References the DOM node used to place the widget

Constructors

HomeViewModel Constructor new HomeViewModel(properties)

Parameter

properties Object

optional

See the properties for a list of all the properties that may be passed into the constructor.

Property Overview

Any properties can be set, retrieved or listened to. See the Watch for changes topic.

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Type	Summary	Class
String	The name of the class.	Accessor
GoToOverride\|null\|undefined	This function provides the ability to override either the MapView goTo() or SceneView goTo() methods.	HomeViewModel
String	The current state of the widget.	HomeViewModel
MapView\|SceneView\|null\|undefined	The view associated with the widget instance.	HomeViewModel
Viewpoint\|null\|undefined	The Viewpoint, or point of view, to zoom to when going home.	HomeViewModel

Property Details

declaredClass Inherited Property declaredClass Stringreadonly Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.7 Accessor since 4.0, declaredClass added at 4.7.

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

goToOverride Property goToOverride GoToOverride |null |undefined Since: ArcGIS Maps SDK for JavaScript 4.8 HomeViewModel since 4.0, goToOverride added at 4.8.

This function provides the ability to override either the MapView goTo() or SceneView goTo() methods.

See also

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);
};

state Property state Stringreadonly

The current state of the widget.

Possible Values:"disabled" |"ready" |"going-home"

Default Value:"disabled"

view Property view MapView |SceneView |null |undefined

The view associated with the widget instance.

viewpoint Property viewpoint Viewpoint |null |undefinedautocast

The Viewpoint, or point of view, to zoom to when going home. The initial value is determined a few different ways:

If no View is provided, the value is null.
If the View is ready, but the Viewpoint is not defined, the initial value of the Viewpoint is determined when the View became ready.
If the View is ready and the Viewpoint is defined by the user, the initial viewpoint value is the user-defined Viewpoint.

Default Value:null

Example

// Creates a viewpoint centered on the extent of a polygon geometry
let vp = new Viewpoint({
  targetGeometry: geom.extent
});

// Sets the model's viewpoint to the Viewpoint based on a polygon geometry
home.ViewModel.viewpoint = vp;

Method Overview

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Return Type	Summary	Class
	Adds one or more handles which are to be tied to the lifecycle of the object.	Accessor
	This function provides the ability to interrupt and cancel the process of navigating the view back to the view's initial extent.	HomeViewModel
Boolean	Emits an event on the instance.	HomeViewModel
	Animates the view to the initial Viewpoint of the view or the value of viewpoint.	HomeViewModel
Boolean	Indicates whether there is an event listener on the instance that matches the provided event name.	HomeViewModel
Boolean	Returns true if a named group of handles exist.	Accessor
Object	Registers an event handler on the instance.	HomeViewModel
	Removes a group of handles owned by the object.	Accessor

Method Details

addHandles Inherited Method addHandles(handleOrHandles, groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor 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();

Parameters

handleOrHandles WatchHandle|WatchHandle []

Handles marked for removal once the object is destroyed.

groupKey *

optional

Key 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.

cancelGo Method cancelGo() Since: ArcGIS Maps SDK for JavaScript 4.9 HomeViewModel since 4.0, cancelGo added at 4.9.

This function provides the ability to interrupt and cancel the process of navigating the view back to the view's initial extent.

emit Method emit(type, event){Boolean} Since: ArcGIS Maps SDK for JavaScript 4.5 HomeViewModel since 4.0, emit added at 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

optional

The event payload.

Returns

Type	Description
Boolean	`true` if a listener was notified

go Method go()

Animates the view to the initial Viewpoint of the view or the value of viewpoint.

hasEventListener Method 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.

hasHandles Inherited Method hasHandles(groupKey){Boolean} Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, hasHandles added at 4.25.

Returns true if a named group of handles exist.

Parameter

groupKey *

optional

A group key.

Returns

Type	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 Method on(type, listener){Object}

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

Parameters

type String|String []

An event or an array of events to listen for.

listener Function

The function to call when the event fires.

Returns

Type 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.

Example

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

removeHandles Inherited Method removeHandles(groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, removeHandles added at 4.25.

Removes a group of handles owned by the object.

Parameter

groupKey *

optional

A group key or an array or collection of group keys to remove.

Example

obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");

Event Overview

Name	Type	Summary	Class
		Fires when the go() method is called.	HomeViewModel

Event Details

go Event go

Fires when the go() method is called.

See also

go()

Example

homeWidget.viewModel.on("go", function(event){
  console.log("updating viewpoint");
});