How to add params to success_url with Stripe - ruby-on-rails

Question

I have a website where I have 3 subscription offers
Offer 1 = 4.99 euros for 30 days. (1 month)
Offer 2 = 12.99 euros for 90 days. (3 month)
Offer 3 = 23.99 euros for 180 days. (6 month)
With stripe I would like to add the right subscription duration depending on the offer chosen by the customer.
How to add a parameter to params?
I want to use it on the success method. How to "inject" my_params in the success_url ?
here is my controller:
class CheckoutController < ApplicationController
before_action :user_logged_in?, only: [:create]
def create
#user = current_user
#total = params[:total].to_d
#session = Stripe::Checkout::Session.create(
payment_method_types: ['card'],
line_items: [
{
name: 'Rails Stripe Checkout',
amount: (#total * 100).to_i,
currency: 'eur',
quantity: 1
},
],
success_url: checkout_success_url + '?session_id={CHECKOUT_SESSION_ID}',
cancel_url: checkout_cancel_url
)
respond_to do |format|
format.js
end
end
def success
#session = Stripe::Checkout::Session.retrieve(params[:session_id])
#payment_intent = Stripe::PaymentIntent.retrieve(#session.payment_intent)
#user = current_user
if params[:my_params] == 2
if #user.sub_lvl < 2
#user.update(sub_lvl: 2)
end
if #user.end_sub_date < Time.now
#user.update(end_sub_date: Time.now + 30.days)
else
#user.update(end_sub_date: end_sub_date + 30.days)
end
end
if params[:my_params] == 3
if #user.sub_lvl < 3
#user.update(sub_lvl: 3)
end
if #user.end_sub_date < Time.now
#user.update(end_sub_date: Time.now + 60.days)
else
#user.update(end_sub_date: end_sub_date + 60.days)
end
end
if params[:my_params] == 4
if #user.sub_lvl < 4
#user.update(sub_lvl: 4)
end
if #user.end_sub_date < Time.now
#user.update(end_sub_date: Time.now + 180.days)
else
#user.update(end_sub_date: end_sub_date + 180.days)
end
end
end
def cancel
#session = Stripe::Checkout::Session.retrieve(params[:session_id])
#payment_intent = Stripe::PaymentIntent.retrieve(#session.payment_intent)
end
private
def user_logged_in?
unless current_user
redirect_to new_user_session_path
end
end
end

Answer 1

To add params you would dynamically generate your Checkout Session success_url when you create your Checkout Session. This would require passing the necessary params to your create method like you do with dynamically accessing the amount.
Alternatively, you could just rely on the amount_subtotal of the Checkout Session to indicate which the Subscription plan.