WKT class

The WKT text format for coordinate and geometry objects.

Rules applied by the format conforms with WKT (Well-known text representation of geometry) formatting of coordinate lists and geometries.

Examples:

  • point (x, y): POINT(10.1 20.2)
  • point (x, y, z): POINT Z(10.1 20.2 30.3)
  • point (x, y, m): POINT M(10.1 20.2 30.3)
  • point (x, y, z, m): POINT ZM(10.1 20.2 30.3 40.4)
  • point with geographic coordinates (lon, lat): POINT(10.1 20.2)
  • box (min-x, min-y, max-x, max-y) with values 10.1 10.1,20.2 20.2:
    • POLYGON((10.1 10.1,20.2 10.1,20.2 20.2,10.1 20.2,10.1 10.1))
  • multi point (with 2D points):
    • MULTIPOINT(10.1 10.1,20.2 20.2,30.3 30.3)
  • line string (with 2D points):
    • LINESTRING(10.1 10.1,20.2 20.2,30.3 30.3)
  • multi line string (with 2D points):
    • MULTILINESTRING((35 10,45 45,15 40,10 20,35 10))
  • polygon (with 2D points):
    • POLYGON((35 10,45 45,15 40,10 20,35 10))
  • multi polygon (with 2D points):
    • MULTIPOLYGON(((35 10,45 45,15 40,10 20,35 10)))
  • coordinates for other geometries with similar principles

Note that WKT does not specify bounding box formatting. Here bounding boxes are formatted as polygons. See also wktLikeFormat that formats them as a point series of two points (min, max).

When getting an encoder from text writer format objects this WKT class provides you COULD use crs parameter to give hints (like axis order, and whether x and y must be swapped when writing) about coordinate reference system in text output. However for the WKT text format such crs information is ignored, x/longitude is always printed before y/latitude regardless of crs axis order.

Constructors

WKT()

Properties

hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Methods

decodeCoordType(String text) → Coords
Decodes a coordinate type from text representing Extended WKT (EWKT) data.
decodeSRID(String text) → int?
Decodes an optional SRID from text representing Extended WKT (EWKT) data.

Constants

coordinate → const TextWriterFormat<CoordinateContent>
The WKT text writer format (encoding only) for coordinate objects.
geometry → const TextFormat<GeometryContent>
The WKT text format (encoding and decoding) for geometry objects.