leaflet-geosearch/src/providers/openCageProvider.ts

Adds support for address lookup (a.k.a. geocoding / geosearching) to Leaflet.

import AbstractProvider, {
  BoundsTuple,
  EndpointArgument,
  LatLng,
  ParseArgument,
  SearchArgument,
  SearchResult,
} from './provider';

export interface RequestResult {
  results: RawResult[];
}

export interface RawResult {
  annotations: {
    DMS: { lat: string; lng: string };
    MGRS: string;
    Maidenhead: string;
    Mercator: { x: number; y: number };
    OSM: {
      edit_url: string;
      note_url: string;
      url: string;
    };
    UN_M49: {
      regions: { [key: string]: string };
      statistical_groupings: string[];
    };
    callingcode: number;
    currency: {
      alternate_symbols: string[];
      decimal_mark: string;
      html_entity: string;
      iso_code: string;
      iso_numeric: string;
      name: string;
      smallest_denomination: number;
      subunit: string;
      subunit_to_unit: number;
      symbol: string;
      symbol_first: number;
      thousands_separator: string;
    };
    flag: string;
    geohash: string;
    qibla: number;
    roadinfo: {
      drive_on: string;
      road: string;
      road_type: string;
      speed_in: string;
    };
    sun: {
      rise: {
        apparent: number;
        astronomical: number;
        civil: number;
        nautical: number;
      };
      set: {
        apparent: number;
        astronomical: number;
        civil: number;
        nautical: number;
      };
    };
    timezone: {
      name: string;
      now_in_dst: number;
      offset_sec: number;
      offset_string: string;
      short_name: string;
    };
    what3words: { words: string };
  };
  bounds: {
    northeast: LatLng;
    southwest: LatLng;
  };
  formatted: string;
  geometry: LatLng;
}

export default class OpenCageProvider extends AbstractProvider<
  RequestResult,
  RawResult
> {
  searchUrl = 'https://api.opencagedata.com/geocode/v1/json';

  endpoint({ query }: EndpointArgument) {
    const params = typeof query === 'string' ? { q: query } : query;
    params.format = 'json';

    return this.getUrl(this.searchUrl, params);
  }

  parse(response: ParseArgument<RequestResult>): SearchResult<RawResult>[] {
    return response.data.results.map((r) => {
      let bounds = null;
      if (r.bounds) {
        bounds = [
          [r.bounds.southwest.lat, r.bounds.southwest.lng], // s, w
          [r.bounds.northeast.lat, r.bounds.northeast.lng], // n, e
        ] as BoundsTuple;
      }
      return {
        x: r.geometry.lng,
        y: r.geometry.lat,
        label: r.formatted,
        bounds,
        raw: r,
      };
    });
  }

  async search(options: SearchArgument): Promise<SearchResult<RawResult>[]> {
    // opencage returns a 400 error when query length < 2
    if (options.query.length < 2) {
      return [];
    }

    return super.search(options);
  }
}