pass_specific_model_values_to_session.rb

class MyController < ApplicationController
  def index
    @model = MyModel.new
    @model.foo = "ABCD"
    @model.bar = "1234"
    session[:my_stuff] = @model.session_vars
  end

  def show
    session[:my_stuff][:foo] # "ABCD"
    session[:my_stuff][:bar] # "1234"
  end
end

class MyModel
  attr_accessor :foo
  attr_accessor :bar

  def session_vars
    {
      :foo => @foo,
      :bar => @bar
    }
  end
end