SnappingControls

Overview

The SnappingControls widget provides a user interface to use alongside the SnappingOptions class. SnappingOptions is a property in Sketch, SketchViewModel, Editor, and EditorViewModel.

This widget has been integrated as part of the Sketch and Editor widgets. Therefore, it will be automatically included when loading either of these widgets and no additional work is needed on the end of the developer.

Take a look at the SnappingControls in the Sketch widget with the sketch-geometries sample.

Using the widget

The SnappingControls widget can be used with the MapView or the SceneView like any other widget. However, this widget is dependent on the SnappingOptions class. Currently, this is only available as a property in the Sketch and Editor widgets, in addition to their respective view models. This means that the SnappingControls widget cannot be utilized as a standalone widget, unless it is being used in conjunction with these supported classes. To use this widget with the Editor, EditorViewModel or SketchViewModel, it must be instantiated and its snappingOptions property must be set to either the Editor's, EditorViewModel's, or SketchViewModel's snappingOptions property.

The following code snippet demonstrates how to use SnappingControls within the Editor widget.

require(["esri/widgets/Editor", "esri/widgets/support/SnappingControls"], (Editor, SnappingControls) => {
  const editor = new Editor({
    view: view
  });

  // create a new instance of the SnappingControls widget
  const snappingControls = new SnappingControls({
    view: view,
    snappingOptions: editor.snappingOptions  // set the Editor's snappingOptions property
  });

  view.ui.add(editor, "top-right");  // adds the Editor widget to the view
  view.ui.add(snappingControls, "top-left"); // adds the SnappingControls widget to the view

});

This widget will automatically detect any layers on the Map that support snapping and the layerlist populates with these FeatureSnappingLayerSources. By default, these layers will be disabled for feature snapping. The layers will be enabled for snapping when a user clicks on the layer title in the layerlist. If there is a desire for these layers to be enabled automatically, set enabled as true.

Known Limitations

Layer types currently supported for snapping include: FeatureLayer, GraphicsLayer, GeoJSONLayer, WFSLayer, CSVLayer, MapNotesLayer (2D only), 3D Object SceneLayer (3D only), and BuildingSceneLayer (3D only).

See also

Example

// Create a new instance of SketchViewModel
const sketchViewModel = new SketchViewModel({
  view: view,
  layer: graphicsLayer
});

// Create a new instance of the SnappingControls widget
const snappingControls = new SnappingControls({
  view: view,
  snappingOptions: sketchViewModel.snappingOptions
});

Constructors

new SnappingControls(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 Working with Properties topic.

Show inherited properties

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Type	Summary	Class
String\|HTMLElement	The ID or node representing the DOM element containing the widget. more details	Widget
String	The name of the class. more details	Accessor
String	Icon which represents the widget. more details	SnappingControls
String	The widget's default CSS icon class. more details	SnappingControls
String	The unique ID assigned to the widget when the widget is created. more details	Widget
String	The SnappingControls widget's default label. more details	SnappingControls
SnappingOptions	The SnappingOptions for sketching. more details	SnappingControls
MapView\|SceneView	The view from which the widget will operate. more details	SnappingControls
SnappingControlsViewModel	The view model for the SnappingControls widget. more details	SnappingControls
Boolean	Indicates whether the widget is visible. more details	Widget
VisibleElements	The visible elements that are displayed within the widget. more details	SnappingControls

Property Details

container String|HTMLElement inherited

The ID or node representing the DOM element containing the widget. This property can only be set once. The following examples are all valid use cases when working with widgets.

Examples

// Create the HTML div element programmatically at runtime and set to the widget's container
const basemapGallery = new BasemapGallery({
  view: view,
  container: document.createElement("div")
});

// Add the widget to the top-right corner of the view
view.ui.add(basemapGallery, {
  position: "top-right"
});

// Specify an already-defined HTML div element in the widget's container

const basemapGallery = new BasemapGallery({
  view: view,
  container: basemapGalleryDiv
});

// Add the widget to the top-right corner of the view
view.ui.add(basemapGallery, {
  position: "top-right"
});

// HTML markup
<body>
  <div id="viewDiv"></div>
  <div id="basemapGalleryDiv"></div>
</body>

// Specify the widget while adding to the view's UI
const basemapGallery = new BasemapGallery({
  view: view
});

// Add the widget to the top-right corner of the view
view.ui.add(basemapGallery, {
  position: "top-right"
});

declaredClass Stringreadonly inherited

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

icon String Since: ArcGIS Maps SDK for JavaScript 4.27

Icon which represents the widget. It is typically used when the widget is controlled by another one (e.g. in the Expand widget).

Default Value:null

See also

Calcite Icon Search

iconClass String Deprecated since 4.27. Use icon instead.

The widget's default CSS icon class.

id String inherited

The unique ID assigned to the widget when the widget is created. If not set by the developer, it will default to the container ID, or if that is not present then it will be automatically generated.

label String

The SnappingControls widget's default label.

snappingOptions SnappingOptionsautocast

The SnappingOptions for sketching. It supports self and feature snapping.

view MapView|SceneView

The view from which the widget will operate.

viewModel SnappingControlsViewModelautocast

The view model for the SnappingControls widget. This class contains all the logic, (ie. properties and methods) that control the widget's behavior. See the SnappingControlsViewModel class to access all of the properties and methods on the SnappingControls widget.

visible Boolean inherited

Indicates whether the widget is visible.

If false, the widget will no longer be rendered in the web document. This may affect the layout of other elements or widgets in the document. For example, if this widget is the first of three widgets associated to the upper right hand corner of the view UI, then the other widgets will reposition when this widget is made invisible. For more information, refer to the CSS display value of "none".

Default Value:true

Example

// Hides the widget in the view
widget.visible = false;

visibleElements VisibleElements

The visible elements that are displayed within the widget. This property provides the ability to turn individual elements of the widget's display on/off.

The image below displays the default SnappingControls widget with all visible elements visible.

snapping-controls-default

In comparison, the following image displays the widget with the feature enabled snapping toggle and the feature snapping layer source layerList turned off.

snapping-controls-example

Example

// This removes the feature enabled snapping toggle and the layerlist.
snappingControls.visibleElements = {
  featureEnabledToggle: false,
  layerList: false
}

Method Overview

Show inherited methods

Hide inherited methods

Return Type	Summary	Class
	Adds one or more handles which are to be tied to the lifecycle of the object. more details	Accessor
String	A utility method used for building the value for a widget's `class` property. more details	Widget
	Destroys the widget instance. more details	Widget
Boolean	Emits an event on the instance. more details	Widget
Boolean	Indicates whether there is an event listener on the instance that matches the provided event name. more details	Widget
Boolean	Returns true if a named group of handles exist. more details	Accessor
Boolean	`isFulfilled()` may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected). more details	Widget
Boolean	`isRejected()` may be used to verify if creating an instance of the class is rejected. more details	Widget
Boolean	`isResolved()` may be used to verify if creating an instance of the class is resolved. more details	Widget
Object	Registers an event handler on the instance. more details	Widget
	Adds one or more handles which are to be tied to the lifecycle of the widget. more details	Widget
	This method is primarily used by developers when implementing custom widgets. more details	Widget
	Removes a group of handles owned by the object. more details	Accessor
Object	This method is primarily used by developers when implementing custom widgets. more details	Widget
	Renders widget to the DOM immediately. more details	Widget
	This method is primarily used by developers when implementing custom widgets. more details	Widget
Promise	`when()` may be leveraged once an instance of the class is created. more details	Widget

Method Details

addHandles(handleOrHandles, groupKey)inherited Since: 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();

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.

classes(classNames){String}inherited

A utility method used for building the value for a widget's class property. This aids in simplifying CSS class setup.

Parameter

classNames String|String []|Object

repeatable

The class names.

Returns

Type	Description
String	The computed class name.

See also

Guide - Custom widget basics (rendering)

Example

// .tsx syntax showing how to set CSS classes while rendering the widget

render() {
  const dynamicIconClasses = {
    [CSS.myIcon]: this.showIcon,
    [CSS.greyIcon]: !this.showIcon
  };

  return (
    <div class={classes(CSS.root, CSS.mixin, dynamicIconClasses)} />
  );
}

destroy()inherited

Destroys the widget instance.

emit(type, event){Boolean}inherited

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

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.

hasHandles(groupKey){Boolean}inherited Since: ArcGIS Maps SDK for JavaScript 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");
}

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.

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|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);
});

own(handleOrHandles)inherited Since: ArcGIS Maps SDK for JavaScript 4.24

Adds one or more handles which are to be tied to the lifecycle of the widget. The handles will be removed when the widget is destroyed.

const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true}
);

this.own(handle); // Handle gets removed when the widget is destroyed.

Parameter

handleOrHandles WatchHandle|WatchHandle []

Handles marked for removal once the widget is destroyed.

postInitialize()inherited

This method is primarily used by developers when implementing custom widgets. Executes after widget is ready for rendering.

removeHandles(groupKey)inherited Since: ArcGIS Maps SDK for JavaScript 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");

render(){Object}inherited

This method is primarily used by developers when implementing custom widgets. It must be implemented by subclasses for rendering.

Returns

Type	Description
Object	The rendered virtual node.

renderNow()inherited

Renders widget to the DOM immediately.

scheduleRender()inherited

This method is primarily used by developers when implementing custom widgets. Schedules widget rendering. This method is useful for changes affecting the UI.

when(callback, errback){Promise}inherited

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`.

Example

// Although this example uses the BasemapGallery widget, any class instance that is a promise may use when() in the same way
let bmGallery = new BasemapGallery();
bmGallery.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
});

Type Definitions

VisibleElements Object

The visible elements that are displayed within the widget. This provides the ability to toggle visibility for individual elements within the widget.

Properties

header Boolean

optional

Indicates whether to display the header. Default is true.

enabledToggle Boolean

optional

Indicates whether to display the enabledToggle (Enable snapping). Default is true. This toggles the SnappingOptions.enabled property.

Note

It is recommended to set SnappingControls.snappingOptions.enabled = true if enabledToggle is set to false. This is because selfEnabledToggle and featureEnabledToggle require snapping globally to be enabled in order to be interactive. Otherwise, these toggles will not be responsive.

selfEnabledToggle Boolean

optional

Indicates whether to display the selfEnabledToggle (Geometry guides). Default is true. This toggles the SnappingOptions.selfEnabled property.

featureEnabledToggle Boolean

optional

Indicates whether to display the featureEnabledToggle (Feature to feature). Default is true. This toggles the SnappingOptions.featureEnabled property.

layerList Boolean

optional

Indicates whether to display the FeatureSnappingLayerSource layerList. Default is true. The layerlist provides the available layer sources supported for snapping.

ArcGIS Maps SDK for JavaScriptAPI Reference

Overview

Using the widget

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