I have a website where I need a javascript version of the "current user" object along with the ruby version. I have been assigning these variables doing something like this...

Application Controller:
def get_user
    begin
      @current_user = User.find(session[:user_id]) if session[:user_id]
      @current_user_json = @current_user.to_json
    rescue
      session.delete(:user_id)
      @current_user = nil
      @current_user_json = {}
    end
  end

Web Page:
var current_user = null;
current_user_json = '<%= @current_user_json %>';
if(current_user_json != ''){
        current_user = current_user_json.user;
}

Even when there is a current user, I get the current user is undefined. Probably because I am putting the current_user_json assignment around single quotes. However, if I don't put it around single quotes, I'll always get a javascript error when no user is logged in because the syntax is invalid -

current_user_json = ;

I think I am just looking at this completely wrong and there must be a better way. Given that this is probably a common thing to do, I wanted to get other people's opinion on how to create an object in javascript that is a duplicate of the ruby object.