placemark / betterknown

modern parser & stringifier for WKT, EWKT, and GeoJSON

betterknown

betterknown development is supported by 🌎 placemark.io

I wrote wellknown, a WKT parser and stringifier, eons ago. It's still sort of popular but nobody maintained it after I left Mapbox.

There's wkx, which is stricter and honestly has a better parser, plus supports WKB, but it's also abandoned and has some drawbacks - no TypeScript, somewhat idiosyncratic code, and the bundle size is larger than it needs to be because it brings in browserify shims.

This project aims to be the combination of the two projects. Lightweight like wellknown, strict and correct like wkx, plus with the 2022 energy of supporting TypeScript from day one.

• 100% TypeScript
• No dependencies - tiny bundle
• Parse WKT to GeoJSON, stringify GeoJSON to WKT
• Optional reprojection of EWKT to GeoJSON's required WGS84 coordinate system

📕 Documentation

Example

import { wktToGeoJSON, geoJSONToWkt } from "betterknown";
import proj4 from "proj4";

// Converting & reprojecting an EWKT string
wktToGeoJSON(`SRID=3857;POINT(-400004.3 60000.1)`, {
  proj: proj4,
});

// Converting GeoJSON to WKT
geoJSONToWkt({
  type: 'Point',
  coordinates: [1, 2]
});

betterknown's Issues

First published version

Set up documentation generation

Probably copy the setup from togeojson and tokml

Define handling of SRID

GeoJSON as of the IETF draft does not support non-WGS84 coordinates. https://www.rfc-editor.org/rfc/rfc7946#section-4

So, deal with what to do with SRID.

My preference:

• Allow an option for projection method, if given, reproject, otherwise throw.

Detect and handle heterogenous coordinates

GeoJSON that can exist:

{
  "type": "LineString",
  "coordinates": [[0, 1, 2], [2, 3]]
}

Should this be a LINESTRING or LINESTRING Z in WKT? Probably just a LINESTRING. This should be detected and handled explicitly.

Option for EMPTY representation

The two options should be:

• null coordinates
• null geometry

With a default, probably, to null coordinates.