Polygon | References | ArcGIS Maps SDK for JavaScript

import Polygon from "@arcgis/core/geometry/Polygon.js";

Inheritance:: Polygon→Geometry→Accessor

Subclasses:: Circle

Since: ArcGIS Maps SDK for JavaScript 4.0

A polygon contains an array of rings and a spatialReference. Each ring is represented as an array of points. The first and last points of a ring must be the same. A polygon also has boolean-valued hasM and hasZ fields.

Known Limitations

The polygon geometries must be simple when added to the following layers:

View.graphics
GraphicsLayer
Feature collections added through FeatureLayer.source

Polygon geometries can be inspected and simplified before they are added to those layers. Use the simplifyOperator to make sure that polygons display correctly on the client-side.

See also

Constructors

Constructor

Parameters

Parameter	Type	Description	Required
properties	`PolygonProperties`

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

Properties

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

Property	Type	Class
`cache` readonly inherited	`Record<string, any>`	Geometry
`centroid` deprecated readonly	`Point \| null \| undefined`
`curveRings`	`CurveJSON[][] \| undefined`
`declaredClass` readonly inherited	`string`	Accessor
`extent` readonly inherited	`Extent \| null \| undefined`	Geometry
`hasM` inherited	`boolean`	Geometry
`hasZ` inherited	`boolean`	Geometry
`rings`	`number[][][]`
`spatialReference` inherited	`SpatialReference`	Geometry
`type` readonly	`"polygon"`

cache

readonlyinherited Property

Type: Record<string, any>

Inherited from: Geometry

The cache is used to store values computed from geometries that need to be cleared or recomputed upon mutation. An example is the extent of a polygon.

centroid

deprecatedreadonly Property

Type: Point | null | undefined

The centroid of the polygon. For a polygon with multiple rings, it represents the centroid of the largest ring.

curveRings

Property

Type: CurveJSON[][] | undefined

An array consisting of points and curve objects that define the polygon geometry.

Example

// Polygon with a circular arc segment represented with a curve object.
const curvedPolygon = new Polygon({
  curveRings: [
    [
      [-14008897.772168774,4219321.966491825],
      {
        c: [
          [-13922799.120303603,4218343.568797498],
          [-13964136.273597848,4258702.324397415]
        ]
      },
      [-13922799.120303603,4218343.568797498],
      [-13923532.913909001,4170157.6736310786],
      [-14010365.378040956,4170402.2683893144],
      [-14008897.772168774,4219321.966491825]
    ]
  ],
  spatialReference: { wkid: 102100 }
});

declaredClass

readonlyinherited Property

Type: string

Inherited from: Accessor

Since: ArcGIS Maps SDK for JavaScript 4.7

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

extent

readonlyinherited Property

Type: Extent | null | undefined

Inherited from: Geometry

The extent of the geometry. For a point, the extent is null.

hasM

inherited Property

Type: boolean

Inherited from: Geometry

Indicates if the geometry has M values.

Default value: false

hasZ

inherited Property

Type: boolean

Inherited from: Geometry

Indicates if the geometry has z-values (elevation).

Z-values defined in a geographic or metric coordinate system are expressed in meters. However, in local scenes that use a projected coordinate system, vertical units are assumed to be the same as the horizontal units specified by the service.

Default value: false

rings

Property

Type: number[][][]

An array of rings. Each ring is a two-dimensional array of numbers representing the coordinates of each vertex in the ring in the spatial reference of the view. The first vertex of each ring should always be the same as the last vertex. Each vertex is an array of two, three, or four numbers. The table below shows the various structures of a vertex array.

Case	Vertex array
without z and without m	[x, y]
without z and with m	[x, y, m]
with z and without m	[x, y, z]
with z and with m	[x, y, z, m]

Example

//3D polygon rings with m-values (note that the second ring does not have m-values defined for it)
const rings = [
  [  // first ring
    [-97.06138,32.837,35.1,4.8],
    [-97.06133,32.836,35.2,4.1],
    [-97.06124,32.834,35.3,4.2],
    [-97.06138,32.837,35.1,4.8]  // same as first vertex
  ], [  // second ring
    [-97.06326,32.759,35.4],
    [-97.06298,32.755,35.5],
    [-97.06153,32.749,35.6],
    [-97.06326,32.759,35.4]  // same as first vertex
 ]
];

const polygon = new Polygon({
  hasZ: true,
  hasM: true,
  rings: rings,
  spatialReference: { wkid: 4326 }
});

spatialReference

autocast inherited Property

Type: SpatialReference

Inherited from: Geometry

The spatial reference of the geometry.

Default value: SpatialReference.WGS84 // wkid: 4326

type

readonly Property

Type: "polygon"

The string value representing the type of geometry.

Methods

Method	Signature	Class
`fromExtent` static	`fromExtent(extent: Extent): Polygon`
`fromJSON` inherited static	`fromJSON(json: any): any`	JSONSupportMixin
`addRing`	`addRing(points: number[][] \| Point[]): this`
`clone`	`clone(): Polygon`
`contains`	`contains(point: Point): boolean`
`getPoint`	`getPoint(ringIndex: number, pointIndex: number): Point \| null \| undefined`
`insertPoint`	`insertPoint(ringIndex: number, pointIndex: number, point: Point \| number[]): this`
`isClockwise`	`isClockwise(ring: number[][] \| Point[]): boolean`
`removePoint`	`removePoint(ringIndex: number, pointIndex: number): Point \| null \| undefined`
`removeRing`	`removeRing(index: number): Point[] \| null \| undefined`
`setPoint`	`setPoint(ringIndex: number, pointIndex: number, point: Point \| number[]): this`
`toJSON` inherited	`toJSON(): any`	JSONSupportMixin

fromExtent

static Method

Signature: fromExtent (extent: Extent): Polygon

Converts the given Extent to a Polygon instance. This is useful for scenarios in which you would like to display an area of interest, which is typically defined by an Extent or bounding box, as a polygon with a fill symbol in the view. Some geoprocessing tools require input geometries to be of a Polygon type and not an Extent.

Parameters

Parameter	Type	Description	Required
extent	`Extent`	An extent object to convert to a polygon.

Returns: Polygon
A polygon instance representing the given extent.

Example

view.on("click", function(evt) {
  const area = Polygon.fromExtent(view.extent);
  const graphic = new Graphic({
    geometry: area,
    symbol: { type: "simple-fill" }
  });
  view.graphics.add(graphic);
});

fromJSON

inheritedstatic Method

Signature: fromJSON (json: any): any

Inherited from: JSONSupportMixin

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.

Parameters

Parameter	Type	Description	Required
json	`any`	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: any
Returns a new instance of this class.

addRing

Method

Signature: addRing (points: number[][] | Point[]): this

Adds a ring to the Polygon. The ring can be one of the following: an array of numbers or an array of points. When added the index of the ring is incremented by one.

Parameters

Parameter	Type	Description	Required
points	`number[][] \| Point[]`	A polygon ring. The first and last coordinates/points in the ring must be the same. This can either be defined as an array of Point geometries or an array of XY coordinates.

Returns: this
Returns the polygon with the new ring included.

clone

Method

Signature: clone (): Polygon

Creates a deep clone of Polygon object.

Returns: Polygon
A new instance of a Polygon object equal to the object used to call .clone().

contains

Method

Signature: contains (point: Point): boolean

Checks on the client if the input point is inside the polygon. A point on the polygon line is considered inside.

Parameters

Parameter	Type	Description	Required
point	`Point`	The point to test whether it is contained within the testing polygon.

Returns: boolean
Returns true if the point is located inside the polygon.

getPoint

Method

Signature: getPoint (ringIndex: number, pointIndex: number): Point | null | undefined

Returns a point specified by a ring and point in the path.

Parameters

Parameter	Type	Description	Required
ringIndex	`number`	The index of the ring containing the desired point.
pointIndex	`number`	The index of the desired point within the ring.

Returns: Point | null | undefined
Returns the point at the specified ring index and point index.

insertPoint

Method

Signature: insertPoint (ringIndex: number, pointIndex: number, point: Point | number[]): this

Inserts a new point into the polygon.

Parameters

Parameter	Type	Description
ringIndex	`number`	The index of the ring in which to insert the point.
pointIndex	`number`	The index of the point to insert within the ring.
point	`Point \| number[]`	The point to insert.

Returns: this
Returns the updated polygon.

isClockwise

Method

Signature: isClockwise (ring: number[][] | Point[]): boolean

Checks if a Polygon ring is clockwise.

Parameters

Parameter	Type	Description	Required
ring	`number[][] \| Point[]`	A polygon ring. It can either be defined as an array of Point geometries or an array of XY coordinates.

Returns: boolean
Returns true if the ring is clockwise and false for counterclockwise.

removePoint

Method

Signature: removePoint (ringIndex: number, pointIndex: number): Point | null | undefined

Removes a point from the polygon at the given pointIndex within the ring identified by ringIndex.

Parameters

Parameter	Type	Description	Required
ringIndex	`number`	The index of the ring containing the point to remove.
pointIndex	`number`	The index of the point to remove within the ring.

Returns: Point | null | undefined
Returns the geometry of the removed point.

removeRing

Method

Signature: removeRing (index: number): Point[] | null | undefined

Removes a ring from the Polygon. The index specifies which ring to remove.

Parameters

Parameter	Type	Description	Required
index	`number`	The index of the ring to remove.

Returns: Point[] | null | undefined
Returns array of points representing the removed ring.

setPoint

Method

Signature: setPoint (ringIndex: number, pointIndex: number, point: Point | number[]): this

Updates a point in the polygon.

Parameters

Parameter	Type	Description
ringIndex	`number`	The index of the ring containing the point to update.
pointIndex	`number`	The index of the point to update within the ring.
point	`Point \| number[]`	The new point geometry.

Returns: this
Returns the updated polygon.

toJSON

inherited Method

Signature: toJSON (): any

Inherited from: JSONSupportMixin

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

Returns: any
The ArcGIS portal JSON representation of an instance of this class.