README.md

gem install geocoder
gem "geocoder"
bundle install
rails generate migration AddLatitudeAndLongitudeToModel latitude:float longitude:float
rake db:migrate
geocoded_by :full_street_address   # can also be an IP address
after_validation :geocode          # auto-fetch coordinates
reverse_geocoded_by :latitude, :longitude
after_validation :reverse_geocode  # auto-fetch address
field :coordinates, :type => Array
field :address
include Geocoder::Model::Mongoid
geocoded_by :address               # can also be an IP address
after_validation :geocode          # auto-fetch coordinates
include Geocoder::Model::Mongoid
reverse_geocoded_by :coordinates
after_validation :reverse_geocode  # auto-fetch address
rake db:mongoid:create_indexes
include Geocoder::Model::Mongoid
geocoded_by :address, :skip_index => true
rake geocode:all CLASS=YourModel
rake geocode:all CLASS=YourModel sleep=0.25
# returns Geocoder::Result object
result = request.location
Venue.near('Omaha, NE, US', 20)    # venues within 20 miles of Omaha
Venue.near([40.71, 100.23], 20)    # venues within 20 miles of a point
Venue.near([40.71, 100.23], 20, :units => :km)
                                   # venues within 20 kilometres of a point
Venue.geocoded                     # venues with coordinates
Venue.not_geocoded                 # venues without coordinates
if obj.geocoded?
  obj.nearbys(30)                      # other objects within 30 miles
  obj.distance_from([40.714,-100.234]) # distance from arbitrary point to object
  obj.bearing_to("Paris, France")      # direction from object to arbitrary point
end
# look up coordinates of some location (like searching Google Maps)
Geocoder.coordinates("25 Main St, Cooperstown, NY")
 => [42.700149, -74.922767]

# distance (in miles) between Eiffel Tower and Empire State Building
Geocoder::Calculations.distance_between([47.858205,2.294359], [40.748433,-73.985655])
 => 3619.77359999382

# find the geographic center (aka center of gravity) of objects or points
Geocoder::Calculations.geographic_center([city1, city2, [40.22,-73.99], city4])
 => [35.14968, -90.048929]
Geocoder::Calculations.compass_point(355) # => "N"
Geocoder::Calculations.compass_point(45)  # => "NE"
Geocoder::Calculations.compass_point(208) # => "SW"
obj.distance_to([43.9,-98.6])  # distance from obj to point
obj.bearing_to([43.9,-98.6])   # bearing from obj to point
obj.bearing_from(obj2)         # bearing from obj2 to obj
geocoded_by :address, :latitude  => :lat, :longitude => :lon # ActiveRecord
geocoded_by :address, :coordinates => :coords                # MongoDB
geocoded_by :address

def address
  [street, city, state, country].compact.join(', ')
end
reverse_geocoded_by :latitude, :longitude, :address => :location  # ActiveRecord
reverse_geocoded_by :coordinates, :address => :loc                # MongoDB
distance = 20
center_point = [40.71, 100.23]
box = Geocoder::Calculations.bounding_box(center_point, distance)
Venue.within_bounding_box(box)
reverse_geocoded_by :latitude, :longitude do |obj,results|
  if geo = results.first
    obj.city    = geo.city
    obj.zipcode = geo.postal_code
    obj.country = geo.country_code
  end
end
after_validation :reverse_geocode
# config/initializers/geocoder.rb
Geocoder.configure(

  # geocoding service (see below for supported options):
  :lookup => :yandex,

  # to use an API key:
  :api_key => "...",

  # geocoding service request timeout, in seconds (default 3):
  :timeout => 5,

  # set default units to kilometers:
  :units => :km,

  # caching (see below for details):
  :cache => Redis.new,
  :cache_prefix => "..."

)
# with Google:
Geocoder.search("Paris", :bounds => [[32.1,-95.9], [33.9,-94.3]])
# with Nominatim:
Geocoder.search("Paris", :params => {:countrycodes => "gb,de,fr,es,us"})
Geocoder.configure(:cache => Redis.new)
Geocoder.configure(:cache_prefix => "...")
Geocoder.cache.expire("http://...") # expire cached result for a URL
Geocoder.cache.expire(:all)         # expire all cached results
class Venue

  # build an address from street, city, and state attributes
  geocoded_by :address_from_components

  # store the fetched address in the full_address attribute
  reverse_geocoded_by :latitude, :longitude, :address => :full_address
end
class Venue

  geocoded_by :address,
    :latitude  => :fetched_latitude,  # this will be overridden by the below
    :longitude => :fetched_longitude  # same here

  reverse_geocoded_by :latitude, :longitude
end
class Venue

  after_validation :geocode, :reverse_geocode

end
 after_validation :geocode
class Venue

  after_validation :reverse_geocode, :if => :has_coordinates
  after_validation :geocode, :if => :has_location, :unless => :has_coordinates

end
results = Geocoder.search("McCarren Park, Brooklyn, NY")
Geocoder.configure(:lookup => :test)

Geocoder::Lookup::Test.add_stub(
  "New York, NY", [
    {
      'latitude'     => 40.7143528,
      'longitude'    => -74.0059731,
      'address'      => 'New York, NY, USA',
      'state'        => 'New York',
      'state_code'   => 'NY',
      'country'      => 'United States',
      'country_code' => 'US'
    }
  ]
)
Geocoder.configure(:lookup => :test)

Geocoder::Lookup::Test.set_default_stub(
  [
    {
      'latitude'     => 40.7143528,
      'longitude'    => -74.0059731,
      'address'      => 'New York, NY, USA',
      'state'        => 'New York',
      'state_code'   => 'NY',
      'country'      => 'United States',
      'country_code' => 'US'
    }
  ]
)
$ geocode 29.951,-90.081
Latitude:         29.952211
Longitude:        -90.080563
Full address:     1500 Sugar Bowl Dr, New Orleans, LA 70112, USA
City:             New Orleans
State/province:   Louisiana
Postal code:      70112
Country:          United States
Google map:       http://maps.google.com/maps?q=29.952211,-90.080563