Polygon | API Reference | ArcGIS Maps SDK for JavaScript 4.31

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 geometryEngine's simplify() method to make sure that polygons display correctly on the client-side.

See also

Constructors

Polygon Constructor new Polygon(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
Object	The cache is used to store values computed from geometries that need to be cleared or recomputed upon mutation.	Geometry
Point	The centroid of the polygon.	Polygon
String	The name of the class.	Accessor
Extent	The extent of the geometry.	Geometry
Boolean	Indicates if the geometry has M values.	Geometry
Boolean	Indicates if the geometry has z-values (elevation).	Geometry
Boolean	Checks to see if polygon rings cross each other and indicates if the polygon is self-intersecting, which means the ring of the polygon crosses itself.	Polygon
Number [][][]	An array of rings.	Polygon
SpatialReference	The spatial reference of the geometry.	Geometry
String	The string value representing the type of geometry.	Polygon

Property Details

cache Inherited Property cache Objectreadonly 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 Property centroid Point

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

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.

extent Inherited Property extent Extentreadonly Inherited from Geometry

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

hasM Inherited Property hasM Boolean Inherited from Geometry

Indicates if the geometry has M values.

hasZ Inherited Property hasZ 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.

isSelfIntersecting Property isSelfIntersecting Boolean

Checks to see if polygon rings cross each other and indicates if the polygon is self-intersecting, which means the ring of the polygon crosses itself.

rings Property rings 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 Inherited Property spatialReference SpatialReferenceautocast Inherited from Geometry

The spatial reference of the geometry.

Default Value:SpatialReference.WGS84 // wkid: 4326

type Property type Stringreadonly

The string value representing the type of geometry.

For Polygon the type is always "polygon".

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
Polygon	Adds a ring to the Polygon.	Polygon
Polygon	Creates a deep clone of Polygon object.	Polygon
Boolean	Checks on the client if the input point is inside the polygon.	Polygon
Polygon	Converts the given Extent to a Polygon instance.	Polygon
*	Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product.	Geometry
Point	Returns a point specified by a ring and point in the path.	Polygon
Boolean	Returns true if a named group of handles exist.	Accessor
Polygon	Inserts a new point into the polygon.	Polygon
Boolean	Checks if a Polygon ring is clockwise.	Polygon
	Removes a group of handles owned by the object.	Accessor
Point []	Removes a point from the polygon at the given `pointIndex` within the ring identified by `ringIndex`.	Polygon
Point []	Removes a ring from the Polygon.	Polygon
Polygon	Updates a point in the polygon.	Polygon
Object	Converts an instance of this class to its ArcGIS portal JSON representation.	Geometry

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.

addRing Method addRing(points){Polygon}

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.

Parameter

points Point []|Number [][]

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

Type	Description
Polygon	Returns the polygon with the new ring included.

clone Method clone(){Polygon}

Creates a deep clone of Polygon object.

Returns

Type	Description
Polygon	A new instance of a Polygon object equal to the object used to call `.clone()`.

contains Method contains(point){Boolean}

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

Parameter

point Point

The point to test whether it is contained within the testing polygon.

Returns

Type	Description
Boolean	Returns `true` if the point is located inside the polygon.

fromExtent Method fromExtent(extent){Polygon}static

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.

Parameter

extent Extent

An extent object to convert to a polygon.

Returns

Type	Description
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 Inherited 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.

getPoint Method getPoint(ringIndex, pointIndex){Point}

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

Parameters

ringIndex Number

The index of the ring containing the desired point.

pointIndex Number

The index of the desired point within the ring.

Returns

Type	Description
Point	Returns the point at the specified ring index and point index.

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");
}

insertPoint Method insertPoint(ringIndex, pointIndex, point){Polygon}

Inserts a new point into the polygon.

Parameters

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

Type	Description
Polygon	Returns the updated polygon.

isClockwise Method isClockwise(ring){Boolean}

Checks if a Polygon ring is clockwise.

Parameter

ring Point []|Number [][]

A polygon ring. It can either be defined as an array of Point geometries or an array of XY coordinates.

Returns

Type	Description
Boolean	Returns `true` if the ring is clockwise and `false` for counterclockwise.

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");

removePoint Method removePoint(ringIndex, pointIndex){Point[]}

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

Parameters

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

Type	Description
Point []	Returns the geometry of the removed point.

removeRing Method removeRing(index){Point[]}

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

Parameter

index Number

The index of the ring to remove.

Returns

Type	Description
Point []	Returns array of points representing the removed ring.

setPoint Method setPoint(ringIndex, pointIndex, point){Polygon}

Updates a point in the polygon.

Parameters

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

Type	Description
Polygon	Returns the updated polygon.

toJSON Inherited Method toJSON(){Object} Inherited from Geometry

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.