This is the controller I'm working with in card_signups (card_signups_controller) I need to add functionality that creates a new 'GiftConversion' class instance for the user when they click on a button in the _social partial.

gistfile1.rb

class CardSignupsController < ApplicationController
  before_filter :require_user_sign_up
  before_filter :require_unique, :only => [:print_temp_card, :update]
  before_filter :get_card_user, :only => [:rewards, :edit, :update, :print_coupon]
  before_filter :get_rewards, :only => [:rewards, :print_coupon, :edit]
  
  skip_before_filter :verify_authenticity_token
  
  def index
    @first_stupid = CardSignup.new
    if params[:secret_user_id].present?
      @referral_card_signup = User.find(params[:secret_user_id])
      @referral = @referral_card_signup.gift_conversions
      @referral << GiftConversion.new
    end
    render
  end
  
  def new
    if params[:user] && current_user.admin
      @card_signup = User.find(params[:user]).build_card_signup
    else
      @card_signup = current_user.build_card_signup
    end
  end
  
  def disclaimer
    batch = CardBatch.current_batch
    batch = CardBatch.create unless batch
    if User.exists?(params[:user]) && current_user.admin
      @card_signup = User.find(params[:user]).build_card_signup(params[:card_signup])
    else
      @card_signup = current_user.build_card_signup(params[:card_signup])
    end
    @card_signup.card_batch = batch
    @card_signup.exp_date = 3.years.from_now

    if @card_signup.save
      2.times{@card_signup.user.gift_conversions << GiftConversion.new}
      Notifier.welcome_message(@card_signup).deliver
      @possible_converts = CardReferral.all.select{|cf|cf.email.downcase == (params[:card_signup][:email]).downcase }
      unless @possible_converts.empty?
        @valid_ref = @possible_converts.find(:order => "created_at").first
        if @valid_ref.email.downcase == @card_signup.email.downcase
          User.find(@valid_ref.user_id).conversions << @card_signup
          Notifier.new_reward_message(User.find(@valid_ref.user_id).card_signup, @card_signup).deliver
        end
      end
      respond_to do |wants|
        wants.html {}
        wants.json { render :json => { :html => (render_to_string :partial => 'final_form')}}
        if params[:user] && current_user.admin
          Notifier.card_signup_email(User.find(params[:user]).card_signup).deliver
          User.find(params[:user]).me_topics << MeTopic.all
        else
          Notifier.card_signup_email(current_user.card_signup).deliver
          current_user.me_topics << MeTopic.all
        end
        
        if @card_signup.organization_id? && Organization.exists?(@card_signup.organization_id)
          org_name = Organization.find(@card_signup.organization_id).name
          org_id = @card_signup.organization_id
          email = Organization.find(@card_signup.organization_id).users.first.email
          Notifier.referral_reward(org_name, org_id, email).deliver
        end
      end
    else
      respond_to do |wants|
        wants.html {}
        wants.json { render :json => { :errors => @card_signup.errors, :html => (render_to_string :partial => 'final_form') } }
      end
    end
  end
  
  def create
    @card_signup ||= params[:card_signup]
    
    if User.exists?(params[:user]) && current_user.admin
      @card_signup = User.find(params[:user]).build_card_signup(params[:card_signup])
    else
      @card_signup = current_user.build_card_signup(params[:card_signup])
    end
    if @card_signup.valid?
      end
      respond_to do |wants|
        wants.json { render :json => {:card_signup => @card_signup, :html => (render_to_string :partial => 'social') } } 
      end
    else
      respond_to do |wants|
        wants.json { render :json => {:errors => @card_signup.errors} }
      end
    end
  end
  
  def edit
    respond_to do |wants|
      wants.json { render :json => { :html => (render_to_string :partial => 'form') } }
      wants.html { render :layout => 'account' }
    end
  end
  
  def update
    params[:card_signup][:dob] = @card_signup.dob
    params[:card_signup][:how_did_you_hear] = @card_signup.how_did_you_hear
    if @card_signup.update_attributes(params[:card_signup])
      respond_to do |wants|
        wants.html { redirect_to edit_card_signup_path(@card_signup) }
        wants.json { render :json => { :html => (render_to_string :partial => 'printing_status') } }
      end
    else
      respond_to do |wants|
        wants.json { logger.info @card_signup.errors.inspect }
        wants.html {render :action => 'edit', :layout => 'account'}
      end
    end
  end


  def destroy
    @card_signup = CardSignup.find(params[:id])
    if @card_signup.organization_id != nil
      @organization = Organization.find(@card_signup.organization_id)
      @organization.update_credits
    end
    @card_signup.destroy
    respond_to do |wants|
      wants.js { render :nothing => true }
    end
  end
  
  def skip_to_end
    @card_signup ||= CardSignup.new(params[:card_signup])
    respond_to do |wants|
      wants.html { redirect_to new_card_signup_path }
      wants.json { render :json => { :html => (render_to_string :partial => '/card_signups/new_form') } }
    end
  end

  def go_to_disclaimer
    @card_signup ||= CardSignup.new(params[:card_signup])
    
    respond_to do |wants|
      wants.html { redirect_to new_card_signup_path }
      wants.json { render :json => { :html => (render_to_string :partial => '/card_signups/disclaimer') } }
    end
  end

  def go_to_final_form
    @card_signup ||= CardSignup.new(params[:card_signup])
    2.times{@current_user.gift_conversions << GiftConversion.new }

    respond_to do |wants|
      wants.html { redirect_to new_card_signup_path }
      wants.json { render :json => { :html => (render_to_string :partial => '/card_signups/final_form') } }
    end
  end

  def skip_to_social
    @card_signup ||= CardSignup.new(params[:card_signup])
    2.times{@card_signup.user.gift_conversions << GiftConversion.new}
    
    respond_to do |wants|
      wants.html { redirect_to new_card_signup_path }
      wants.json { render :json => { :html => (render_to_string :partial => '/card_signups/social') } }
    end
  end
  
  def print_temp_card
    options = {:page_layout=>:landscape}
    ["left","right","top","bottom"].each do |side|
      options[(side + '_margin').to_sym] = 36
    end
    prawnto :inline=>true, :prawn=>options, :filename => "temp_card.pdf"
  end
  
  def rewards
    render :layout => 'account'
  end

  end
  
  def print_coupon
    @used_reward = (@gifts + @conversions).first
    @org = Organization.find(params[:org])
    
    if @unused_orgs.include?(@org) && (@conversions.count + @gifts.count) > 0
      @used_reward.update_attribute("referred_organization_id", params[:org])
      @used_reward.update_attribute("used_referral_reward_at", DateTime.now)
      Notifier.org_reward_used_message(@org, @user).deliver
      options = {:page_layout=>:landscape, :page_size => [400, 700]}
      ["left","right","top","bottom"].each do |side|
        options[(side + '_margin').to_sym] = 36
      end
      prawnto :inline=> true, :prawn=> options, :filename => "HQCard_Gift.pdf"
    
    else
      redirect_to root_url
    end
  end
  
  def redeem_facebook
    @card_signup = current_user.card_signup
    @card_signup.redeem_facebook!
  end
  
  private
  
  def get_rewards
    @conversions = @card_signup.user.conversions.find(:all, :conditions => ["used_referral_reward_at IS ? OR used_referral_reward_at < ?", nil, (Date.today - 1.years)])
    @gifts = @card_signup.user.gift_conversions.find(:all, :conditions => ["used_referral_reward_at IS ? OR used_referral_reward_at < ?", nil, (Date.today - 1.years)])
    
    @ref_orgs = Organization.find(:all, :conditions => ["offering_referral = ?", true])
    @soiled_converts = @card_signup.user.conversions.find(:all, :conditions => ["used_referral_reward_at > ?", (Date.today - 1.years)])
    @soiled_gifts = @card_signup.user.gift_conversions.find(:all, :conditions => ["used_referral_reward_at > ?", (Date.today - 1.years)])
    @unused_orgs = (@ref_orgs - @soiled_converts.collect{|e|Organization.find(e.referred_organization_id)} - @soiled_gifts.collect{|sg|Organization.find(sg.referred_organization_id)}).sort{|a,b| b.offering_referral_timestamp <=> a.offering_referral_timestamp}
  end
  
  def require_unique
    begin
      @unique_user = current_user.card_signup.id == params[:id].to_i
      @unique_user = CardSignup.find(params[:id]) if @unique_user.blank? && current_user.admin
    rescue
      @unique_user = CardSignup.find(params[:id]) if current_user.admin
    end
    redirect_to root_path unless @unique_user
  end
  
  def get_card_user
    if params[:org]
      @user = User.find(params[:id])
      @card_signup = @user.card_signup
    elsif current_user.admin
      @user = CardSignup.find(params[:id]).user
      @card_signup = CardSignup.find(params[:id])
    else
      @user = current_user
      @card_signup = current_user.card_signup
    end
    redirect_to login_url unless @card_signup
  end