GeoJSON class

The GeoJSON text format for coordinate, geometry and feature objects.

Rules applied by the format conforms with the GeoJSON formatting of coordinate lists and geometries.

Examples:

• point (x, y):
  • {"type":"Point","coordinates":[10.1,20.2]}
• point (x, y, z):
  • {"type":"Point","coordinates":[10.1,20.2,30.3]}
• box (min-x, min-y, max-x, max-y), as a property inside other object:
  • "bbox": [10.1,10.1,20.2,20.2]
• box (min-x, min-y, min-z, max-x, max-y, maz-z), as a property:
  • "bbox": [10.1,10.1,10.1,20.2,20.2,20.2]

Multi point (with 2D points): {"type":"MultiPoint","coordinates":[[10.1,10.1],[20.2,20.2],[30.3,30.3]]}

Line string (with 2D points): {"type":"LineString","coordinates":[[10.1,10.1],[20.2,20.2],[30.3,30.3]]}

Multi line string (with 2D points):

  {"type":"MultiLineString",
   "coordinates":[[[10.1,10.1],[20.2,20.2],[30.3,30.3]]]}

Polygon (with 2D points):

  {"type":"Polygon",
   "coordinates":[[[35,10],[45,45],[15,40],[10,20],[35,10]]]}

MultiPolygon (with 2D points):

  {"type":"Polygon",
   "coordinates":[[[[35,10],[45,45],[15,40],[10,20],[35,10]]]]}

Feature:

  {"type": "Feature",
   "id":1,
   "properties": {"prop1": 100},
   "geometry": {"type":"Point","coordinates":[10.1,20.2]}}

The GeoJSON specification about M coordinates: "Implementations SHOULD NOT extend positions beyond three elements because the semantics of extra elements are unspecified and ambiguous. Historically, some implementations have used a fourth element to carry a linear referencing measure (sometimes denoted as "M") or a numerical timestamp, but in most situations a parser will not be able to properly interpret these values. The interpretation and meaning of additional elements is beyond the scope of this specification, and additional elements MAY be ignored by parsers."

This implementation allows printing M coordinates, when available on source data. Such M coordinate values are always formatted as "fourth element.". However, it's possible that other implementations cannot read them:

• point (x, y, m), with z missing but formatted as 0, and m = 40.4:
  • {"type":"Point","coordinates":[10.1,20.2,0,40.4]}
• point (x, y, z, m), with z = 30.3 and m = 40.4:
  • {"type":"Point","coordinates":[10.1,20.2,30.3,40.4]}

Available extensions

• GeoJSONExtension

Constructors

GeoJSON()

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

parser<T extends Point<num>>(PointFactory<T> point, {CreateBounds<T>? bounds, CreateFeature? feature}) → GeoJsonFactory<T>

Available on GeoJSON, provided by the GeoJSONExtension extension

A GeoJSON factory using point factory to create any points of T.

parserGeographic<T extends GeoPoint>(PointFactory<T> point, {CreateBounds<T>? bounds, CreateFeature? feature}) → GeoJsonFactory<T>

Available on GeoJSON, provided by the GeoJSONExtension extension

A GeoJSON factory using point factory to create geographic points of T.

parserProjected<T extends ProjectedPoint<num>>(PointFactory<T> point, {CreateBounds<T>? bounds, CreateFeature? feature}) → GeoJsonFactory<T>

Available on GeoJSON, provided by the GeoJSONExtension extension

A GeoJSON factory using point factory to create cartesian points of T.

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

coordinateFormat({GeoJsonConf? conf}) → TextWriterFormat<CoordinateContent>

The GeoJSON text format (encoding only) for coordinate objects with optional conf.

featureFormat({GeoJsonConf? conf}) → TextFormat<FeatureContent>

The GeoJSON text format (encoding and decoding) for feature objects with optional conf.

geometryFormat({GeoJsonConf? conf}) → TextFormat<GeometryContent>

The GeoJSON text format (encoding and decoding) for geometry objects with optional conf.

Constants

coordinate → const TextWriterFormat<CoordinateContent>

The GeoJSON text format (encoding only) for coordinate objects.

feature → const TextFormat<FeatureContent>

The GeoJSON text format (encoding and decoding) for feature objects.

geometry → const TextFormat<GeometryContent>

The GeoJSON text format (encoding and decoding) for geometry objects.