leaflet-control-geocoder/src/geocoders/what3words.ts

Extendable geocoder with builtin support for OpenStreetMap Nominatim, Bing, Google, Mapbox, MapQuest, What3Words, Photon, Pelias, HERE, Neutrino, Plus codes

import * as L from 'leaflet';
import { getJSON } from '../util';
import { IGeocoder, GeocoderOptions, geocodingParams, GeocodingResult, reverseParams } from './api';

export interface What3WordsOptions extends GeocoderOptions {}

/**
 * Implementation of the What3Words service
 */
export class What3Words implements IGeocoder {
  options: What3WordsOptions = {
    serviceUrl: 'https://api.what3words.com/v2/'
  };

  constructor(options: Partial<What3WordsOptions>) {
    L.Util.setOptions(this, options);
  }

  async geocode(query: string): Promise<GeocodingResult[]> {
    const data = await getJSON<any>(
      this.options.serviceUrl + 'forward',
      geocodingParams(this.options, {
        key: this.options.apiKey,
        //get three words and make a dot based string
        addr: query.split(/\s+/).join('.')
      })
    );
    const results: GeocodingResult[] = [];
    if (data.geometry) {
      const latLng = L.latLng(data.geometry['lat'], data.geometry['lng']);
      const latLngBounds = L.latLngBounds(latLng, latLng);
      results[0] = {
        name: data.words,
        bbox: latLngBounds,
        center: latLng
      };
    }
    return results;
  }

  suggest(query: string): Promise<GeocodingResult[]> {
    return this.geocode(query);
  }

  async reverse(location: L.LatLngLiteral, scale: number): Promise<GeocodingResult[]> {
    const data = await getJSON<any>(
      this.options.serviceUrl + 'reverse',
      reverseParams(this.options, {
        key: this.options.apiKey,
        coords: [location.lat, location.lng].join(',')
      })
    );
    const results: GeocodingResult[] = [];
    if (data.status.status == 200) {
      const center = L.latLng(data.geometry['lat'], data.geometry['lng']);
      const bbox = L.latLngBounds(center, center);
      results[0] = {
        name: data.words,
        bbox: bbox,
        center: center
      };
    }
    return results;
  }
}

/**
 * [Class factory method](https://leafletjs.com/reference.html#class-class-factories) for {@link What3Words}
 * @param options the options
 */
export function what3words(options: Partial<What3WordsOptions>) {
  return new What3Words(options);
}