So, the key method of invitation to a private beta is that you mail someone a code allowing them access to the system, for these purposes, let’s just assume that the code is some reasonably long unique string (in my code, it’s actually a uuid.) So, set up a migration something like this to manage them:

  def self.up
    create_table :invites do |t|
# deleted stuff
      t.string :guid
      t.integer :used_yet
# deleted stuff
    end
  end

used_yet isn’t a boolean for reasons that are too laborious to go into here, but reflect some functionality in the code that I’m not going to display. Assuming that you’re using acts_as_authentication and are redirecting anyone who tries to access your app to the default welcome page according to the usual methods, set up something like this in your routes.rb:

  map.root :controller => "welcome"

This is probably the case in like half the rails apps out there. Have the index method of the welcome controller put up a form with a field like:

#let's see if the formatter can handle rails erb without exploding.
< % form_tag('welcome/checkinvite', :method=>:get) do -%>
  < %= text_field_tag 'invite' %>
  < %= submit_tag 'begin' %>
< % end -%>

This lets the user enter their invite in more or less the normal method. Now in your ‘welcome’ controller, you’ll need a ‘checkinvite’ method that looks something like the following:

 def checkinvite
    @inviteguid = params[:invite]
    @invite = Invite.find_by_guid(@inviteguid)
    if(@invite == nil)
      flash[:notice] = "Your invite was invalid"
      redirect_to root_url
      return
    end
    if(@invite.used_yet == 1)
      flash[:notice] = "Your invite had already been used"
      redirect_to root_url
      return
    end
  end

After this, you’ll need to have some code in your HTML page that links you to the account/signup functionality of acts_as_authenticated. I’m not going to include that because I’m too lazy to fish it out of my app functionality, but you can do that pretty much with a link_to using :invite=%gt;@invite_guid as an extra parameter.

You need to put the same invite detection code in account/signup, and then when you’ve created the account, set invite.used_yet = 1. This is about as simple as a method that I can think of for doing the private beta functionality that seems to be so much in vogue these days. Enjoy.