SnappingOptions | API Reference | ArcGIS Maps SDK for JavaScript 4.31

The SnappingOptions allows users to configure snapping for their editing or drawing experience in both the Sketch and Editor widgets.

Snapping options provide the ability to specify whether an application will utilize self snapping, feature snapping, or both. Both are described below.

It is also possible to toggle snapping by pressing and holding down the CTRL key. This toggles the snapping on/off.

Self snapping (Geometry guides)

Self snapping is set via the selfEnabled property. This means that while a user is actively creating or updating a feature or graphic, they will see visualizations to help identify perpendicular and parallel lines, in addition to visualizations which aid in snapping to an extension of an existing feature. The following briefly demonstrates what self snapping looks like in a 2D application. Although this is shown for 2D, the same premise applies for 3D as well.

self-snapping

Feature snapping

Feature snapping is set via the featureEnabled property. It provides the ability to snap vertices of a graphic or feature that is currently being drawn or reshaped to that of an existing feature's vertex, edge, or end point. These existing features belong to layers within the Map and must be specified in the featureSources property. The following two images demonstrate feature snapping in a 2D application. Similar to self snapping, the same premise applies for 3D as well.

feature-snapping-create

The above shows feature snapping to an existing feature's vertex endpoint and edge while creating a new feature. The bottom demonstrates taking an existing feature and reshaping its geometry to snap to another feature's vertex points.

feature-snapping-update

Things to consider:

Layer types currently supported for snapping are: FeatureLayer, GraphicsLayer (except Mesh geometries), GeoJSONLayer, WFSLayer, CSVLayer, MapNotesLayer (2D only), 3D Object SceneLayer (3D only), and BuildingSceneLayer (3D only).
Snapping is not yet implemented when using the Sketch widget's circle tool. It will be addressed in a future release.
Enabling snapping via the CTRL key is not currently supported using the Sketch widget's rectangle and circle tools. However, snapping can still be activated by setting the snappingOptions.enabled property to true in the Sketch widget or its view model. Note that this enables snapping for all tools. This behavior is subject to change in a future release.

Name	Details	3D Example	2D Example
Rectangle	Snap lines that are perpendicular to each other
Parallel	Snap to all parallel lines
Extension	Snap to an extension of the current shape
Vertex (as seen when updating geometries)	Snap vertices to an existing vertex

See also

Example

// Create a new instance of Sketch, and set
// a layer for one of the featureSources property.
// This enables feature snapping on that layer.
const sketch = new Sketch({
  layer: graphicsLayer,
  view: view,
  snappingOptions: { // autocasts to SnappingOptions()
    enabled: true, // global snapping is turned on
    // assigns a collection of FeatureSnappingLayerSource() and enables feature snapping on this layer
    featureSources: [{ layer: graphicsLayer, enabled: true }]
  }
});

Constructors

SnappingOptions Constructor new SnappingOptions(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.

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Type	Summary	Class
Boolean	When true, enables support for attribute rule-based snapping.	SnappingOptions
String	The name of the class.	Accessor
Number	Snapping distance for snapping in pixels.	SnappingOptions
Boolean	Global configuration to turn snapping on or off.	SnappingOptions
Boolean	Global configuration option to turn feature snapping on or off.	SnappingOptions
Collection<FeatureSnappingLayerSource>	List of sources for feature snapping.	SnappingOptions
Boolean	Turns the grid on or off.	SnappingOptions
Boolean	Global configuration option to turn self snapping (within one feature while either drawing or reshaping) on or off.	SnappingOptions

Property Details

attributeRulesEnabled Property attributeRulesEnabled Boolean Since: ArcGIS Maps SDK for JavaScript 4.30 SnappingOptions since 4.19, attributeRulesEnabled added at 4.30.

When true, enables support for attribute rule-based snapping. When enabled, resources needed for rule-based snapping, including any Utility Networks present in the map, will be automatically loaded.

Default Value:false

declaredClass Inherited Property declaredClass Stringreadonly Inherited from Accessor

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

distance Property distance Number

Snapping distance for snapping in pixels.

Default Value:5

enabled Property enabled Boolean

Global configuration to turn snapping on or off. Note that snapping is turned off by default.

Default Value:false

featureEnabled Property featureEnabled Boolean

Global configuration option to turn feature snapping on or off.

Default Value:true

featureSources Property featureSources Collection<FeatureSnappingLayerSource>

List of sources for feature snapping. Please refer to FeatureSnappingLayerSource for additional information on what layer sources are supported.

gridEnabled Property gridEnabled Boolean Since: ArcGIS Maps SDK for JavaScript 4.31 SnappingOptions since 4.19, gridEnabled added at 4.31.

Turns the grid on or off. The grid is a network of columns and rows used to divide the view into equal-area squares. The GridControls provides a user interface to interact and configure the grid's properties.

Note

It is recommended to wait for the view to be loaded first before setting the gridEnabled prop in the GridControls constructor. The grid is dependent on the view to be loaded first for it to be displayed.

This grid is only supported in a 2D MapView.

Default Value:false

See also

GridControls

Example

// Turn on the grid programmatically for the GridControls.
// Wait for the view to load first.
view.when(() => {
  const gridControls = new GridControls({
    view,
    snappingOptions: {
      enabled: true,
      gridEnabled: true
    }
  });
  // Add GridControls to the view
  view.ui.add(gridControls, "top-left");
});

selfEnabled Property selfEnabled Boolean

Global configuration option to turn self snapping (within one feature while either drawing or reshaping) on or off.

Default Value:true

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
Boolean	Returns true if a named group of handles exist.	Accessor
	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.

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");
}

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");