wkt-parser-helper/dist/index.js

Module to help parse GeoJSONs to WKT and back

import { geoJSONToWkt, wktToGeoJSON } from "betterknown";
import { klona } from "klona/json";
const EMPTY_GEOMETRY_COLLECTION_WKT = 'GEOMETRYCOLLECTION EMPTY';
function geometryToWkt(geojson) {
    return geoJSONToWkt(geojson);
}
function featureToWkt(geojson) {
    return geometryToWkt(geojson.geometry);
}
function featureCollectionToWkt(featureCollection) {
    if ('FeatureCollection' !== featureCollection.type) throw new Error('GeoJSON is not a FeatureCollection');
    return 0 === featureCollection.features.length ? EMPTY_GEOMETRY_COLLECTION_WKT : `GEOMETRYCOLLECTION(${featureCollection.features.map((d)=>featureToWkt(d)).join(',')})`;
}
function geojsonToWkt(geojson) {
    switch(geojson.type){
        case 'Feature':
            return featureToWkt(geojson);
        case 'FeatureCollection':
            return featureCollectionToWkt(geojson);
        default:
            return geometryToWkt(geojson);
    }
}
function featureCollectionToWktList(geojson) {
    return geojson.features.map((d)=>({
            wkt: geometryToWkt(d.geometry),
            ...d.properties
        }));
}
function wktToGeojson(item, asFeature = false, properties = {}) {
    let parsed;
    parsed = item === EMPTY_GEOMETRY_COLLECTION_WKT ? {
        type: 'GeometryCollection',
        geometries: []
    } : wktToGeoJSON(item);
    if (asFeature) return {
        type: 'Feature',
        geometry: parsed,
        properties
    };
    return parsed;
}
function stripZCoordinates(coords) {
    if ('number' == typeof coords[0]) return coords.slice(0, 2);
    return coords.map(stripZCoordinates);
}
function geojson3dTo2d(geojson) {
    const newGeoJSON = klona(geojson);
    function processGeometry(geom) {
        if (null == geom) return null;
        const type = geom.type;
        switch(type){
            case 'Point':
            case 'MultiPoint':
            case 'LineString':
            case 'MultiLineString':
            case 'Polygon':
            case 'MultiPolygon':
                geom.coordinates = stripZCoordinates(geom.coordinates);
                break;
            case 'GeometryCollection':
                geom.geometries = geom.geometries.map(processGeometry);
                break;
            default:
                throw new Error(`geometry type not supported: ${type}`);
        }
        return geom;
    }
    function processFeature(feature) {
        if (feature.geometry) feature.geometry = processGeometry(feature.geometry);
        return feature;
    }
    if ('Feature' === newGeoJSON.type) return processFeature(newGeoJSON);
    if ('FeatureCollection' === newGeoJSON.type) {
        newGeoJSON.features = newGeoJSON.features.map(processFeature);
        return newGeoJSON;
    }
    return processGeometry(newGeoJSON);
}
function wkt3dTo2d(wkt) {
    const geojson = wktToGeojson(wkt);
    return geojsonToWkt(geojson3dTo2d(geojson));
}
export { EMPTY_GEOMETRY_COLLECTION_WKT, featureCollectionToWkt, featureCollectionToWktList, featureToWkt, geojson3dTo2d, geojsonToWkt, geometryToWkt, wkt3dTo2d, wktToGeojson };