gmgale / wtk-vector-geometry-reader-writer

🌎 Vector geometry objects <-> WKT converter.

WTK Vector Geometry Reader/Writer

Helper classes to convert vector geometry objects to and from WKT.

Read more about WKT here.

The reader/writer classes can handle the most common geometry objects, including deeply nested geometry collection objects.

To run all tests:

npm i
npm run test

Reader

The reader takes a WKT string and returns a class/object/GeometryCollection(of nested classes/objects).
Example:

reader.read("POLYGON ((4, 6, 7, 10), (1, 2, 3, 7))");
reader.read("
  GEOMETRYCOLLECTION (POINT (4 6),
  LINESTRING (4 6, 7 10),
  MULTIPOLYGON (((4 6), (1 2)), (3 4)))");

Produces the classes/objects:

Polygon { values: [ [ 4, 6, 7, 10 ], [ 1, 2, 3, 7 ] ] }
GeometryCollection {
     values: [ [ [Point], [LineString], [MultiPolygon] ] ]
 }

Writer

The writer takes an instance of a Geometric class/object/GeometryCollection(of nested classes/objects) and returns a WKT formatted string.
Example:

writer.write(new Geo.MultiPoint([4, 6], [1, 2]));
writer.write(new Geo.GeometryCollection([
      new Geo.Point(),
      new Geo.LineString([3,4]),
      new Geo.MultiPolygon()
    ]));

Produces the WKT formatted strings:

"MULTIPOINT ((4, 6), (1, 2))"
"GEOMETRYCOLLECTION (POINT EMPTY, LINESTRING (3 4), MULTIPOLYGON EMPTY)"

Empty constructors

As seen in the above example, if the constructor for the Geometry class receives no arguments, 'EMPTY' will take it' place. The isEmpty() method can be called on any instance of a Geometry to check its values.