@qalincalabs/limosa

Limosa [alpha]

Address geolocation javascript library on top of Open Street Map (OSM) open source public APIs : Photon (Komoot) for searching, Nominatim for decorating.

Important: Since Photon and Nominatim are free to use please be fair and avoid excessive requests.

Define an address (house, street, locality, postal code, region, country). Limosa then query Photon successive layers and compute a best match, get the exact place (if possible) and places above that (such as country, locality).

Strict ! For instance, if a housenumber doesn't exist in OSM, the geocoder will only output the street.

Usage

import * as limosa from "@qalincalabs/limosa";

const photonResult = await limosa.photonLocate({
  house: "14",
  street: "Quai des Saulx",
  locality: "Bouillon",
  postalCode: "6830",
  country: "Belgium"
});

const uuids = limosa.extractOsmUuids(photonResult)
const nominatimResult = await limosa.nominatimLookup(
  { osm_ids: uuids },
  //{ format: "jsonv2", addressdetails: 1, namedetails: 1, extratags: 1 }
);

/*
photonResult is
{
  "match": {
    "countrycode": "BE",
    "state": "Luxembourg",
    "county": "Neufchâteau",
    "city": "Bouillon",
    "district": "Bouillon",
    "postcode": "6830",
    "street": "Quai des Saulx",
    "housenumber": "14"
  },
  "exactFeature": {
    "geometry": {
      "coordinates": [
        5.069359068004883,
        49.7938062
      ],
      "type": "Point"
    },
    "type": "Feature",
    "properties": {
      "osm_id": 422861107,
      "extent": [
        5.069283,
        49.7938544,
        5.0694352,
        49.7937584
      ],
      "country": "België / Belgique / Belgien",
      "city": "Bouillon",
      "countrycode": "BE",
      "postcode": "6830",
      "county": "Neufchâteau",
      "type": "house",
      "osm_type": "W",
      "osm_key": "tourism",
      "housenumber": "14",
      "street": "Quai des Saulx",
      "district": "Bouillon",
      "osm_value": "attraction",
      "name": "Archéoscope Godefroid de Bouillon",
      "state": "Luxembourg"
    }
  },
  "upperFeatures": [
    // ...
  ]
}
*/

TODOs

• A place (like a shop) without a street number isn't exactly located
• Plug with https://github.com/openvenues/libpostal (need to find a public API)

Custom geocoder [ON HOLD]

The geocoder started with this but it's now put on the side

Strategies

• OFN BE -> input/output samples

How to

import { Geocoder, ofnBeProfile, nominatimGetDetails } from "@qalincalabs/limosa";

const geocoder = new Geocoder(ofnBeProfile); // replace ofnBeProfile with your own defined profile

// the input has your address structure
const result = await geocoder.locate({
  address1: "Grand rue 40",
  country_id: 29,
  country_name: "Belgium",
  zipcode: "6850",
  city: "Carlsbourg",
});

/*
result is
{
  electedMatch: {
    countrycode: "BE",
    state: "Luxembourg",
    county: "Neufchâteau",
    city: "Paliseul",
    district: "Carlsbourg",
    postcode: "6850",
    street: "Grand Rue",
    housenumber: "40",
  },
  electedOsmElement: {
    id: "890827177",
    type: "W",
  },
}
*/