CODEWITHSUNDEEP
javascriptnode.jsmongodbobjectgeonames
Levi Roberts
Levi Roberts

Reputation: 1317

How to process geonames city data in Node.JS

So I understand that this isn't the traditional way to share code but seeing how there isn't anything on the stack about how to accomplish such a task - I figured I'd share.

To further explain, I looked everywhere for an easy to use Node.JS module to process geonames data into a mongo database. The select few projects I found turned out to be a bust. Perhaps people aren't sharing because it really is such a simple task. With that said, I still think it could be valuable to share what I have.

The following answer will show how to process geonames data from http://geonames.org into a usable object that can then be saved into a database or just used out right.

Upvotes: 1

Views: 2260

Answers (2)

Levi Roberts
Levi Roberts

Reputation: 1317

To further extend the above answer. I have included an example that uses the geonames Node.JS module from Github. ( https://github.com/bugs181/geonames )

Disclaimer: I am the author of the aforementioned github repo.

This example can also be found on the Github repo.

var geonames = require('./geonames.js');

// Intialize geonames module.
geonames.init();

// 34.0500, -118.2500 - Los Angeles, California - More specifically Bunker Hill, California
// 34.057°N 118.238°W - San Francisco, California - More specifically Opera Plaza, California

geonames.city(34.0500, -118.2500, function(err, result) {
        if (err) {
                console.log("There was an error resolving coordinates.");
                console.log(err);
                return;
        }

        console.log("Result: " + JSON.stringify(result, true, 3));
});


Output:

[geonames] Resolve city from coordinates. [34.05, -118.25]
Result: {
   "city": "Bunker Hill",
   "state": "CA"
}


You may use strings for the latitude and longitude as well but you must convert them for the Mongo database. Use the Number() method to do this.

For example:

var lat = "34.0500";
var lon = "-118.2500";

geonames.city(Number( lat ), Number( lon ), function(err, result) {

Upvotes: 0

Levi Roberts
Levi Roberts

Reputation: 1317

var lineReader = require('line-reader');

lineReader.eachLine('./geonames-data/US/US.txt', function(line, last) {

  var city = line.split('\t').structure();

  if (city.is) { // if this is a city.

    // Delete un-needed object properties so we don't add useless info to DB.
    delete city.is;
    delete city.type;

    // Do something with the city object.
    console.log(JSON.stringify(city, true, 3) + '\n');
  }

});


Array.prototype.structure = function() {
    // from geonames readme: - P.PPL    populated place a city, town, village, or other agglomeration of buildings where people live and work
    return {
        _id: Number(this[0]),
        name: this[1],
        state: this[10],
        country: this[8],
        coordinates: [this[4], this[5]],
        timezone: this[17],
        is: ((this[6] == "P") ? true : false), // if object type is city.
        type: ((this[6] == "P") ? "city" : "other") // todo: add a parse function to parse other geonames db types
    }
}

Upvotes: 2

Related Questions