SpatialReference

AMD: require(["esri/geometry/SpatialReference"], (SpatialReference) => { /* code goes here */ });
ESM: import SpatialReference from "@arcgis/core/geometry/SpatialReference.js";
Class: esri/geometry/SpatialReference
Inheritance: SpatialReference Accessor
Since: ArcGIS Maps SDK for JavaScript 4.0

Defines the spatial reference of a view, layer, or method parameters. This indicates the projected or geographic coordinate system used to locate geographic features in the map. Each projected and geographic coordinate system is defined by either a well-known ID (WKID) or a definition string (WKT). Note that for versions prior to ArcGIS 10, only WKID was supported. For a full list of supported spatial reference IDs and their corresponding definition strings, see Using spatial references.

Examples
// set the spatial reference of a view to WebMercator using wkid
const view = new SceneView({
  container: "viewDiv",
  map: map,
  spatialReference: {
    wkid: 3857
  }
});
// set the spatial reference of a geometry
// to WGS84 using the WGS84 property
const point = new Point({
  x: 10.1,
  y: 47.4,
  spatialReference: SpatialReference.WGS84
});

Constructors

SpatialReference

Constructor
new SpatialReference(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 Hide inherited properties
Name Type Summary Class

The name of the class.

Accessor

An image coordinate system defines the spatial reference used to display the image in its original coordinates without distortion, map transformations or ortho-rectification.

SpatialReference

Indicates if the spatial reference refers to a geographic coordinate system.

SpatialReference

Indicates if the wkid of the spatial reference object is one of the following values: 102113, 102100, 3857.

SpatialReference

Indicates if the wkid of the spatial reference object is 4326.

SpatialReference

Indicates if the spatial reference of the map supports wrapping around the International Date Line.

SpatialReference

The factor to convert one unit value in the spatial reference's unit to meters.

SpatialReference

The unit of the spatial reference.

SpatialReference

A convenience spatial reference instance for Web Mercator.

SpatialReference

A convenience spatial reference instance for WGS84.

SpatialReference

The well-known ID of a spatial reference.

SpatialReference

The well-known text that defines a spatial reference.

SpatialReference

The well-known text of the coordinate system as defined by OGC standard for well-known text strings.

SpatialReference

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.

imageCoordinateSystem

Property
imageCoordinateSystem Object
Since: ArcGIS Maps SDK for JavaScript 4.13 SpatialReference since 4.0, imageCoordinateSystem added at 4.13.

An image coordinate system defines the spatial reference used to display the image in its original coordinates without distortion, map transformations or ortho-rectification. Typically, ImageryLayer is displayed in the spatialReference of the view. In some cases, converting images into map coordinates can cause your images to look skewed or distorted because of the various transformations and terrain corrections that are used. Since there is no distortion with images in the image coordinate system, it is ideal for using with oblique imagery and mensuration.

The image can be displayed in its original coordinates only in 2D MapView with a top-uprotation which is always oriented in the look of direction of the dataset. This works similarly to an in-car navigation system where the choices are often either north is at the top of the screen (therefore, not using a top up option) or the screen rotates so the travel direction is always displayed at the top.

Example
// get image coordinate system of the specified catalog item
// for example Raster.OBJECTID = 1600
layer.getCatalogItemICSInfo(imageId).then(function(info) {
// create a spatialReference object and set its
// imageCoordinateSystem property
 let sr = { // autocasts to esri/geometry/SpatialReference
   imageCoordinateSystem: { id: imageId }
 };

 // Calculate an extent for the mapview based on the image's extent
 // in its original coordinate system
 const width = document.getElementById("viewDiv").getBoundingClientRect().width;
 const height = document.getElementById("viewDiv").getBoundingClientRect().height;
 const newExt = info.icsExtent.clone();
 const scaleFactor = 5;
 newExt.xmin = (newExt.xmin + newExt.xmax - width * scaleFactor) / 2;
 newExt.xmax = newExt.xmin + width * scaleFactor;
 newExt.ymin = (newExt.ymin + newExt.ymax - height * scaleFactor) / 2;
 newExt.ymax = newExt.ymin + height * scaleFactor;
 newExt.spatialReference = sr;

 // set the MapView's spatialReference to the image's coordinate system
 // and the extent to the extent calculated above
 view = new MapView({
   container: "viewDiv",
   map: map,
   spatialReference: sr,
   extent: newExt
 });
});

isGeographic

Property
isGeographic Booleanreadonly

Indicates if the spatial reference refers to a geographic coordinate system.

isWebMercator

Property
isWebMercator Booleanreadonly

Indicates if the wkid of the spatial reference object is one of the following values: 102113, 102100, 3857.

isWGS84

Property
isWGS84 Booleanreadonly

Indicates if the wkid of the spatial reference object is 4326.

isWrappable

Property
isWrappable Booleanreadonly

Indicates if the spatial reference of the map supports wrapping around the International Date Line. Value is true if the spatial reference is Web Mercator or WGS84.

metersPerUnit

Property
metersPerUnit Numberreadonly
Since: ArcGIS Maps SDK for JavaScript 4.26 SpatialReference since 4.0, metersPerUnit added at 4.26.

The factor to convert one unit value in the spatial reference's unit to meters.

Examples
// Convert 1 pixel in a MapView to meters
const pixelInMeter = view.resolution * view.spatialReference.metersPerUnit;
// Measure the geodesic distance between two points in the view's unit
const distanceInViewUnit = geodesicUtils.geodesicDistance(pointA, pointB, "meters")  / view.spatialReference.metersPerUnit;
const DPI = 96
const inchesPerMeter = 39.37;

// Get the scale for an extent
function getScale(extent, viewWidth) {
  const unitValue = extent.spatialReference.metersPerUnit;
  return (extent.width / viewWidth) * unitValue * inchesPerMeter * DPI;
}

unit

Property
unit null |Stringreadonly
Since: ArcGIS Maps SDK for JavaScript 4.26 SpatialReference since 4.0, unit added at 4.26.

The unit of the spatial reference. Returns null if no unit could be determined.

Some values of the possible values listed here cannot be used as parameters for certain functions. For example, geodesicUtils.geodesicDistance() only accepts meters, feet, us-feet. For other values, you can use the meters unit and use metersPerUnit convert to the spatial reference's unit.

Possible Values:"degrees" |"meters" |"feet" |"us-feet" |"clarke-feet" |"clarke-yards" |"clarke-links" |"sears-yards" |"sears-feet" |"sears-chains" |"benoit-1895-b-chains" |"indian-yards" |"indian-1937-yards" |"gold-coast-feet" |"sears-1922-truncated-chains" |"50-kilometers" |"150-kilometers"

See also

WebMercator

Property
WebMercator SpatialReferencestatic

A convenience spatial reference instance for Web Mercator.

Example
// returns true if the webMercatorUtils can
// project geometries from WGS84 to Web Mercator
let canProjectWGS84toWebMercator = webMercatorUtils.canProject(SpatialReference.WGS84, SpatialReference.WebMercator);

WGS84

Property
WGS84 SpatialReferencestatic

A convenience spatial reference instance for WGS84.

Example
// returns true if the webMercatorUtils can
// project geometries from WGS84 to Web Mercator
let canProjectWGS84toWebMercator = webMercatorUtils.canProject(SpatialReference.WGS84, SpatialReference.WebMercator);

wkid

Property
wkid Number

The well-known ID of a spatial reference. See Using spatial references for a list of supported spatial references.

wkt

Property
wkt String

The well-known text that defines a spatial reference.

wkt2

Property
wkt2 String
Since: ArcGIS Maps SDK for JavaScript 4.28 SpatialReference since 4.0, wkt2 added at 4.28.

The well-known text of the coordinate system as defined by OGC standard for well-known text strings.

Method Overview

Show inherited methods Hide inherited methods
Name Return Type Summary Class

Adds one or more handles which are to be tied to the lifecycle of the object.

Accessor

Returns a deep clone of the spatial reference object.

SpatialReference

Checks if the specified spatial reference object has the same wkid or wkt as this spatial reference object.

SpatialReference
*

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product.

SpatialReference

Returns true if a named group of handles exist.

Accessor

Removes a group of handles owned by the object.

Accessor

Converts an instance of this class to its ArcGIS portal JSON representation.

SpatialReference

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.

clone

Method
clone(){SpatialReference}

Returns a deep clone of the spatial reference object.

Returns
Type Description
SpatialReference Returns a deep clone of the spatial reference object.

equals

Method
equals(spatialReference){Boolean}

Checks if the specified spatial reference object has the same wkid or wkt as this spatial reference object.

Parameter
spatialReference SpatialReference

The spatial reference to compare to.

Returns
Type Description
Boolean Returns true if the input spatial reference object has the same wkid or wkt as this spatial reference object.
Example
require(["esri/geometry/SpatialReference"], function(SpatialReference) {
  const sr1 = new SpatialReference({ wkid: 4326 });
  const sr2 = new SpatialReference({ wkid: 4326 });
  console.log(sr1.equals(sr2)); // true
});

fromJSON

Method
fromJSON(json){*}static

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product. The object passed into the input json parameter often comes from a response to a query operation in the REST API or a toJSON() method from another ArcGIS product. See the Using fromJSON() topic in the Guide for details and examples of when and how to use this function.

Parameter
json Object

A JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects.

Returns
Type Description
* Returns a new instance of this class.

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");

toJSON

Method
toJSON(){Object}

Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.

Returns
Type Description
Object The ArcGIS portal JSON representation of an instance of this class.

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