geocoder/providers/geonames.js

node wrapper around google's geocoder api

// xml2js is optional because only needed for geonames support
var xml2js = require("xml2js");
var request = require("request");
var _ = require('underscore');

exports.geocode = function ( providerOpts, loc, cbk, opts ) {

  var options = _.extend({q: loc, maxRows: 10, username:providerOpts.username||"demo" }, opts || {});

  request({
    uri:"http://api.geonames.org/searchJSON",
    qs:options
  }, function(err,resp,body) {
    if (err) return cbk(err);
    var result;
    try {
      result = JSON.parse(body);
    } catch (err) {
      cbk(err);
      return;
    }
    cbk(null,result);
  });
};

exports.reverseGeocode = function ( providerOpts, lat, lng, cbk, opts ) {

  var options = _.extend({lat:lat, lng:lng, username:providerOpts.username||"demo" }, opts || {});

  request({
    uri:"http://api.geonames.org/extendedFindNearby",
    qs:options
  }, function(err,resp,body) {
    if (err) return cbk(err);

    var parser = new xml2js.Parser();
    parser.parseString(body, function (err, result) {
      if (err) return cbk(err); 

      // Transform geonames' structure into something that looks like Google's JSON outpu
      // https://developers.google.com/maps/documentation/geocoding/#JSON
      var googlejson = {
        "status":"OK",
        "results":[
          {
            "address_components":[],
            "formatted_address":"",
            "geometry":{
              "location":{
                "lat":lat,
                "lng":lng
              }
            }
          }
        ]
      };

      if (result.geonames.address) {
        var a = result.geonames.address[0];

        if (a.streetNumber && typeof a.streetNumber[0]=="string")
          googlejson.results[0].address_components.push({
            "long_name":a.streetNumber[0],
            "short_name":a.streetNumber[0],
            "types":["street_number"]
          });

        if (a.street && typeof a.street[0]=="string")
          googlejson.results[0].address_components.push({
            "long_name":a.street[0],
            "short_name":a.street[0],
            "types":["route"]
          });

        if (a.placename && typeof a.placename[0]=="string")
          googlejson.results[0].address_components.push({
            "long_name":a.placename[0],
            "short_name":a.placename[0],
            "types":["locality", "political"]
          });

        if (a.adminName1 && typeof a.adminName1[0]=="string")
          googlejson.results[0].address_components.push({
            "long_name":a.adminName1[0],
            "short_name":a.adminCode1[0],
            "types":[ "administrative_area_level_1", "political" ]
          });

        if (a.adminName2 && typeof a.adminName2[0]=="string")
          googlejson.results[0].address_components.push({
            "long_name":a.adminName2[0],
            "short_name":a.adminCode2[0],
            "types":[ "administrative_area_level_2", "political" ]
          });

        if (a.countryCode && typeof a.countryCode[0]=="string")
          googlejson.results[0].address_components.push({
            "long_name":a.countryCode[0]=="US"?"United States":"",
            "short_name":a.countryCode[0],
            "types":[ "country" ]
          });

        if (a.lat && typeof a.lat[0]=="string")
          googlejson.results[0].geometry.location = {
            "lat":parseFloat(a.lat[0]),
            "lng":parseFloat(a.lng[0])
          }
      }

      if (result.geonames.geoname) {
        // http://www.geonames.org/export/codes.html
        // https://developers.google.com/maps/documentation/geocoding/#Types
        var fcode2google = {
          "ADM1":[ "administrative_area_level_1", "political" ],
          "ADM2":[ "administrative_area_level_2", "political" ],
          "ADM3":[ "administrative_area_level_3", "political" ],
          "ADMD":[ "political"],
          "PPL" :[ "locality"]
        };

        result.geonames.geoname.forEach(function(geoname) {

          // Push only recognized types to results
          if (geoname.fcode[0]=="PCLI") {
            googlejson.results[0].address_components.push({
              "long_name":geoname.name[0],
              "short_name":geoname.countryCode[0],
              "types":[ "country", "political"]
            });
          
          } else if (fcode2google[geoname.fcode[0]]) {


            googlejson.results[0].address_components.push({
              "long_name":geoname.toponymName[0],
              "short_name":geoname.name[0],
              "types":fcode2google[geoname.fcode[0]]
            });
          }

        });
      }

      // Make a formatted address as well as we can
      var shortNames = {};
      googlejson.results[0].address_components.forEach(function(c) {
        if (c.types[0]=="country") return shortNames.country = c.long_name || c.short_name;
        shortNames[c.types[0]] = c.short_name;
      });

      var formatted = [];
      if (shortNames.street_number || shortNames.route) {
        formatted.push((shortNames.street_number?shortNames.street_number+" ":"")+shortNames.route);
      }
      if (shortNames.locality) {
        formatted.push(shortNames.locality);
      }
      if (shortNames.administrative_area_level_1) {
        formatted.push(shortNames.administrative_area_level_1);
      }
      if (shortNames.country) {
        formatted.push(shortNames.country);
      }

      googlejson.results[0].formatted_address = formatted.join(", ");

      cbk(null, googlejson);
    });
  });

};