Facebook-ish "people you may know" thingie

gistfile1.rb

class User < ActiveRecord::Base
  has_many :friends, :through => :friendships
  has_many :friendships, :dependent => :destroy
 
  def getMutualFriendsWith user
    intersection = friends() & user.friends()
  end
  
  def getNumberOfMutualFriendsWith user
    getMutualFriendsWith(user).length()
  end
  
  def findPeopleMightKnown
    pymk = []
    for friend in friends() 
      pymk.push(friend.friends())
    end
    pymk.flatten!
    pymk.uniq!
    pymk = (pymk - friends()) - [self]
    pymk.sort! { |a,b| b.getNumberOfMutualFriendsWith(self) <=> a.getNumberOfMutualFriendsWith(self) }
    pymk.reject! {|x| x.getNumberOfMutualFriendsWith(self) == 0 }
    return pymk
  end

end