DRY Rails controller to avoid repeating multiple times same method - ruby-on-rails

Question

I would like to DRY my controller as I use some snippets/blocks of code many times inside the same controller (I have removed some as it was too long but this already gives an idea of the repetition). Here are the blocks I keep repeating :
#deal = search_deal
#next_deal = find_next_deal
#userdeal = find_or_create_userdeal_participation
#user_credits = calculate_user_credits_in_deal
I'm quite rookie and don't know how to do this but I feel this code should be factorized.
class DealsController < ApplicationController
before_filter :find_deal,
:only => [ :showcase ]
before_filter :ensure_canonical_deal_path!,
:only => [ :showcase ]
def showcase
# find appropriate deal
#deal = search_deal
respond_to do |format|
format.html # showcase.html.erb
format.json { render json: #deal }
end
end
def buy_stuff
#deal = search_deal
# bring 'next deal' url to the view
#next_deal = find_next_deal
# USER IS SIGNED-IN
if user_signed_in?
#userdeal = find_or_create_userdeal_participation
#user_credits = calculate_user_credits_in_deal
# if: user still has credits available
if #user_credits >= 1
#do this
respond_to do |format|
format.js
end
else
respond_to do |format|
# do that
end
end
# USER IS NOT SIGNED-IN
else
respond_to do |format|
format.js { render :template => "deals/call_to_sign_in.js.erb" }
end
end
end
def show_discounts
#deal = search_deal
respond_to do |format|
#do that
end
end
def pending_deals
#deal = search_deal
# bring 'next deal' url to the view
#next_deal = find_next_deal
if user_signed_in?
#userdeal = find_or_create_userdeal_participation
#user_credits = calculate_user_credits_in_deal
end
respond_to do |format|
#do this
end
end
def ask_question
#deal = search_deal
respond_to do |format|
#do that
end
end
protected
def ensure_canonical_deal_path!
if request.path != actual_deal_page_path(#deal)
redirect_to actual_deal_page_path(#deal, :format => params[:format]), :status => :moved_permanently
return false
end
end
private
# DRY file as this is used multiple times
# trick source - http://blog.rstankov.com/rails-anti-pattern-setting-view-variables-in-before-actions/
def search_deal
Deal.friendly.find(params[:id])
end
def find_or_create_userdeal_participation
UserDeal.where('user_id = ? AND deal_id = ?', current_user.id, #deal.id).take ||
UserDeal.create(user_id: current_user.id, deal_id: #deal.id)
end
def calculate_user_credits_in_deal
current_user.credit_nb + #userdeal.history
end
def find_next_deal
Deal.order_next_deal_at(#deal).next
end
end

Answer 1

I think the best way to just add before_filters for those methods where you are calling repeat code like:
before_filter :search_deal, :only => [:showcase, :buy_stuff, ...]

Answer 2

class DealsController < ApplicationController
before_filter :find_deal, only: [:showcase]
before_filter :ensure_canonical_deal_path!, only: [:showcase]
def showcase
search_deal
respond_to do |format|
format.html
format.json{render json: #deal}
end
end
def buy_stuff
search_deal
find_next_deal
if user_signed_in?
find_or_create_userdeal_participation
calculate_user_credits_in_deal
if #user_credits >= 1
respond_to(&:js)
else
respond_to{|format| }
end
else
respond_to{|format| format.js{render template: "deals/call_to_sign_in.js.erb"}}
end
end
def show_discounts
search_deal
respond_to{|format|}
end
def pending_deals
search_deal
find_next_deal
if user_signed_in?
find_or_create_userdeal_participation
calculate_user_credits_in_deal
end
respond_to{|format| }
end
def ask_question
search_deal
respond_to{|format| }
end
protected def ensure_canonical_deal_path!
if request.path != actual_deal_page_path(#deal)
redirect_to actual_deal_page_path(#deal, format: params[:format]), status: :moved_permanently
return false
end
end
private def search_deal
#deal = Deal.friendly.find(params[:id])
end
private def find_or_create_userdeal_participation
#user_deal =
UserDeal.where('user_id = ? AND deal_id = ?', current_user.id, #deal.id).take ||
UserDeal.create(user_id: current_user.id, deal_id: #deal.id)
end
private def calculate_user_credits_in_deal
#user_credits = current_user.credit_nb + #userdeal.history
end
private def find_next_deal
#next_deal = Deal.order_next_deal_at(#deal).next
end
end