This repo is archived – no longer maintained. Please fork if you need it!

All the cities of the world (according to the periodically updated MaxMind database).

To use this gem, you'll need the JSON data.

Download it, extract it and connect it up as follows.

$ wget https://s3-us-west-2.amazonaws.com/cities-gem/cities.tar.gz
$ tar -xzf cities.tar.gz

Cities.data_path = '/path/to/cities'

Countries are identified by their ISO 3166-1 alpha-2 codes.

cities = Cities.cities_in_country('GB')
  #=> { "abberley"=> #<City:0x000001049b9ba0>, "abberton"=> #<City:0x000001049b9b50>, ... }

mcr = cities['manchester']
  #=> #<City:0x00000102fb4ea8>

mcr.name
  #=> "Manchester"

mcr.population
  #=> 395516

mcr.latlong
  #=> [53,5, -2.216667]

The database is exhaustive and certainly stretches the definition of the word "city".

Cities.cities_in_country('GB')['buchlyvie'].population
  #=> 448

This gem was designed as an extension to the Countries gem. Installing Cities adds two new instance methods to the Country class.

us = Country.search('US')
  #=> #<Country:0x000001020cf5f0>

us.cities?
  #=> true

us.cities
  #=> { "abanda" => #<Cities::City:0x00000114b34a38>, ...  }

Sometimes you may want to not constantly want to read and parse the same large JSON data files. So by default we cache in memory the parsed JSON. To turn this off simply set the cache_data flag to false

Country.cache_data = false

Country.configure do |config|
  config.data_path = '../data/cities'
  config.cache_data = false
end

The default path for data is the following path

GEM_ROOT/data/cities

Or you can set the environment variable DATA_PATH

To run the specs bundle and run specs

=> bundle
=> rake

Provided under an MIT license by Joe Corcoran. Thanks to hexorx for the countries gem that brought this idea about.

This product includes data created by MaxMind, available from http://www.maxmind.com. All data © 2008 MaxMind Inc. Read the MaxMind WorldCities open data license for more details.