Question

I have a Ruby on Rails app that allows the user to login with their Facebook account. I want to be able to a list of users and their Facebook data. I have been able to accomplish this however I have to send a request for each user’s name and I want to do this as a batch operation. How would I be able to put this in my user model?

User Model

class User < ActiveRecord::Base
  attr_accessible :uid

  def facebook_name
    Koala::Facebook::API.new.get_object(uid)["name"].to_s
  end
end

Example of Inefficient code

users = Users.all

users.each do |user|
  puts user.facebook_name
end

Answer 1

Use a background task (such as https://github.com/collectiveidea/delayed_job) to populate the data in the database.

For example

class User
 after_create :delayed_populate

 def populate_from_facebook
   self.facebook_name = Koala::Facebook::API.new.get_object(uid)["name"].to_s
 end

 def delayed_populate
   delay.populate_from_facebook
 end 
end

Then, once you’ve done that, it’s just a regular model database to iterate through them, as the fields will be cached in your DB. You really don’t want to be making HTTP api requests during responding to another HTTP request.