ngageoint / simple-features-js

Simple Features JS

Simple Features Javascript

Simple Features Lib

The Simple Features Libraries were developed at the National Geospatial-Intelligence Agency (NGA) in collaboration with BIT Systems. The government has "unlimited rights" and is releasing this software to increase the impact of government investments by providing developers with the opportunity to take things in new directions. The software use, modification, and distribution rights are stipulated within the MIT license.

Pull Requests

If you'd like to contribute to this project, please make a pull request. We'll review the pull request and discuss the changes. All pull request contributions to this project will be released under the MIT license.

Software source code previously released under an open source license and then modified by NGA staff is considered a "joint work" (see 17 USC § 101); it is partially copyrighted, partially public domain, and as a whole is protected by the copyrights of the non-government authors and must be released according to the terms of the original open source license.

About

Simple Features is a Javascript library of geometry objects and utilities based upon the OGC Simple Feature Access standard.

Simple Feature Conversion Libraries

• simple-features-wkb-js - Well Known Binary
• simple-features-wkt-js - Well Known Text
• simple-features-geojson-js - GeoJSON
• simple-features-proj-js - Projection

Usage

View the latest JS Docs

Browser Usage

<script src="/path/to/simple-features-js/dist/sf.min.js"></script>

const { Point, LineString, Polygon } = window.SimpleFeatures;

const point = new Point(0, 0);
const lineString = new LineString(point);
const polygon = new Polygon(lineString)

Node Usage

Pull from NPM

npm install --save simple-features-js

const { Point, LineString, Polygon } = require("@ngageoint/simple-features-js");

const point = new Point(0, 0);
const lineString = new LineString(point);
const polygon = new Polygon(lineString)

Build

Build this repository using Node.js:

npm install
npm run build

simple-features-js's Issues

The `js_cols` dependency breaks modern setups

Problem

This library is not functional out of the box when using a modern setup like vite v5 and typescript v5 which impacts @ngageoint/grid-js and @ngageoint/mgrs-js usage. It looks like the js_cols dependency is improperly bundled which blows up on "Uncaught ReferenceError: js_cols is not defined"

I'm unsure why exactly this works in commonjs vs es modules + vite. Regardless, js_cols does not have a very robust bundle (see https://github.com/thomasstjerne/js_cols/blob/master/dist/js_cols.min.js).

Ideal Solution

Shim or fix js_cols so that downstream users of libraries like @ngageoint/mgrs-js don't have to.

Steps to Reproduce

1. Generate vite project i.e. npm create vite@latest my-app -- --template vanilla-ts
2. Add the following to the index.html in the body tag

       <script type="module">
         import * as gridJs from '@ngageoint/grid-js';
         import * as mgrsJs from '@ngageoint/mgrs-js';
         console.log(mgrsJs.MGRS.from(gridJs.Point.degrees(0, 0)));
       </script>

Temp Workaround

See below for my temp temp solution. This defines the js_cols variable on global scope. It's later overridden when the library is imported.

        <script type="module">
          // This goes before the main bundle in the body
          window.js_cols = undefined;
        </script>

Environment

• vite v5
• node v20
• typescript v5