'distance' field gets dropped when using Geokit with acts_as_mappable :through - ruby-on-rails

Question

We know that the distance field gets dropped when using the Geokit gem in Rails with acts_as_mappable :through model class. I wonder if there's a way to work around this to get the distance field back. I tried to follow the monkey-patching example over here:
http://www.sobyteme.com/news/2010/05/13/computers/2010/06/25/geokit-acts_as_mappable-through-with-distance-attribute/
but it didn't work for me.

Answer 1

Well, Steve's suggestion over on his site was accurate, I was missing calling sort_by_distance_from after doing the find. So credit goes to him for this answer.
I'm on Rails v3.0.7. Here's my code:
class Office < ActiveRecord::Base
has_many :users
acts_as_mappable :default_units => :miles,
:default_formula => :sphere,
:lat_column_name => :latitude,
:lng_column_name => :longitude
end
class User < ActiveRecord::Base
belongs_to :office
acts_as_mappable :through => :office
end
users_controller.rb:
# Monkey patching to include the 'distance' attribute
module Geokit
module Mappable
def to_lat_lng
return self if instance_of?(Geokit::LatLng) || instance_of?(Geokit::GeoLoc)
return LatLng.new(self.office.send(self.office.class.lat_column_name),
self.office.send(self.office.class.lng_column_name)) if self.class.respond_to?(:acts_as_mappable)
nil
end
end
end
class UsersController < ApplicationController
def location
#lat = params[:lat].to_f
#long = params[:long].to_f
#origin = [#lat, #long]
#users = User.find(:all,
:origin => #origin,
:conditions => "distance < 3")
# We have to add this to get the 'distance' field
#users.sort_by_distance_from(#origin)
respond_to do |format|
format.html
format.xml { render :xml => #users.to_xml(:methods => :distance)}
format.json { render :json => #users.to_json(:methods => :distance)}
end
end
...
end