Visit - Geocoder - : undefined method `geocoded_by' for #<Class:0x007fbefbacde30> (NoMethodError)

gistfile1.txt

./models/visit.rb

class Visit < ActiveRecord::Base

  attr_accessible :ip_address, :country, :city, :latitude, :longitude
  belongs_to :link

  geocoded_by :ip_address
  after_validation :geocode

end
--------------------------------------------
./service.rb

require 'rubygems'
require 'bundler/setup'

require 'active_record'
require 'geocoder'
require 'sinatra'
require 'sinatra/activerecord'

require 'json'
require 'alphadecimal'


require "#{File.dirname(__FILE__)}/models/link"
require "#{File.dirname(__FILE__)}/models/url"
require "#{File.dirname(__FILE__)}/models/visit"

logger = Logger.new(STDOUT)

['/info/:short_url', '/info/:short_url/:num_of_days', '/info/:short_url/:num_of_days/:map'].each do |path|
  get path do
    link = Link.find_by_identifier(params[:short_url])
    if link
      link.to_json(:include => :visits)
    else
      error 404, "This link is not defined yet".to_json
    end
  end
end

get '/:short_url' do
  logger.info("inside short url")
  link = Link.find_by_identifier(params[:short_url])
  if link
    logger.info("request location inspect: " + request.location.inspect)
    link.visits.create(:ip_address => get_remote_ip(env), :city => request.location.city, :country => request.location.country, :latitude => request.location.latitude, :longitude => request.location.longitude)
    link.save
    redirect link.url.original_url, 301
  else
    logger.info("link not found")
    error 404, "Link not found".to_json
  end
end

get '/' do
  "Hello World"
end

error do
  "Error"
end

def get_remote_ip(env)
  if addr = env['HTTP_X_FORWARDED_FOR']
    addr.split(',').first.strip
  else
    env['REMOTE_ADDR']
  end
end

------------------------------------
Error

: undefined method `geocoded_by' for #<Class:0x007fbefbacde30> (NoMethodError)
	from /Users/mwagner72/Dropbox/rails_projects/antgs/models/visit.rb:6:in `<class:Visit>'
	from /Users/mwagner72/Dropbox/rails_projects/antgs/models/visit.rb:1:in `<top (required)>'
	from /Users/mwagner72/Developer/.rvm/gems/ruby-1.9.2-p180@antgs/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
	from /Users/mwagner72/Developer/.rvm/gems/ruby-1.9.2-p180@antgs/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `block in require'
	from /Users/mwagner72/Developer/.rvm/gems/ruby-1.9.2-p180@antgs/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `block in load_dependency'
	from /Users/mwagner72/Developer/.rvm/gems/ruby-1.9.2-p180@antgs/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:596:in `new_constants_in'
	from /Users/mwagner72/Developer/.rvm/gems/ruby-1.9.2-p180@antgs/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `load_dependency'
	from /Users/mwagner72/Developer/.rvm/gems/ruby-1.9.2-p180@antgs/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
	from /Users/mwagner72/Dropbox/rails_projects/antgs/service.rb:15:in `<top (required)>'
	from /Users/mwagner72/Developer/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
	from /Users/mwagner72/Developer/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'