How to set up a callback in an initializer? - ruby-on-rails

Question

I'm using Koudoku for subscriptions. I want to do different things after receiving a Stripe webhook.
In the docs, it shows you can add a callback like so:
Koudoku.setup do |config|
config.subscriptions_owned_by = :user
config.stripe_publishable_key = ENV['STRIPE_PUBLISHABLE_KEY']
config.stripe_secret_key = ENV['STRIPE_SECRET_KEY']
# add webhooks
config.subscribe 'charge.failed', YourChargeFailed
end
What I can't figure out how to write the YourChargeFailed part. I've tried something like:
config.subscribe 'order.payment_succeeded', ActiveRecord::Subscription.after_successful_payment
but I get undefined method after_successful_payment for #<Class:0x007fb845849b30>
How can I successfully subscribe to Stripe events, capture the return data, and initiate a callback function?
Thanks!
UPDATE
Here is what I've tried, and the corresponding errors I'm receiving:
purchases_helper.rb
module PurchasesHelper
require 'stripe'
def stripe_webhook(event)
puts 'Purchases Helper'
puts 'invoice.payment_succeeded'
#customer = Stripe::Customer.retrieve(event[:data][:object][:customer])
#user = User.find_by(email: #customer[:email])
#badge = Badge.find_by(condition: '2019Purchase')
#badges_user = BadgesUser.find_by(user_id: #user.id, badge_id: #badge.id)
# if #badges_user === nil
# BadgesUser.create(user_id: user.id, badge_id: badge.id)
# end
puts 'badge created'
end
end
initializers/koudoku.rb
Koudoku.setup do |config|
include ::PurchasesHelper
config.subscribe 'charge.succeeded' do |event|
puts 'charge created'
::PurchasesHelper.stripe_webhook(event)
end
end
ERROR:
undefined method `stripe_webhook' for PurchasesHelper:Module excluded from capture: Not configured to send/capture in environment 'development'
NoMethodError (undefined method `stripe_webhook' for PurchasesHelper:Module):
Another attempt:
Koudoku.setup do |config|
config.subscribe 'charge.succeeded' do |event|
puts 'charge created'
PurchasesHelper.stripe_webhook(event)
end
end
ERROR:
undefined method `stripe_webhook' for PurchasesHelper:Module excluded from capture: Not configured to send/capture in environment 'development'
NoMethodError (undefined method `stripe_webhook' for PurchasesHelper:Module):
3rd Attempt:
Koudoku.setup do |config|
include PurchasesHelper
config.subscribe 'charge.succeeded' do |event|
puts 'charge created'
stripe_webhook(event)
end
end
ERROR:
A copy of PurchasesHelper has been removed from the module tree but is still active! excluded from capture: Not configured to send/capture in environment 'development'
ArgumentError (A copy of PurchasesHelper has been removed from the module tree but is still active!):

Answer 1

I see only one problem with your code.
module PurchasesHelper
require 'stripe'
def self.stripe_webhook(event) # NB self.
puts 'Purchases Helper'
puts 'invoice.payment_succeeded'
#customer = Stripe::Customer.retrieve(event[:data][:object][:customer])
#user = User.find_by(email: #customer[:email])
#badge = Badge.find_by(condition: '2019Purchase')
#badges_user = BadgesUser.find_by(user_id: #user.id, badge_id: #badge.id)
# if #badges_user === nil
# BadgesUser.create(user_id: user.id, badge_id: badge.id)
# end
puts 'badge created'
end
end
and then you call it by saying
Koudoku.setup do |config|
config.subscribe 'charge.succeeded' do |event|
puts 'charge created'
PurchasesHelper.stripe_webhook(event)
end
end
This should work
Wait but Why?!
Modules are a way of grouping together methods, classes, and constants. Modules give you two major benefits.
provide a namespace and prevent name clashes
implement the mixin facility (when you include them)
You've defined an instance method on the Module that when included it will appear on every instance of the object.
but you are not doing that in this case. You want to call stripe_webhook on the Module itself.
adding self. stripe_webhook in this case = PurchasesHelper. stripe_webhook which is the way to define a methods on the class/module.
You can even do more freaky stuff like:
class Animal
def self.all
%w[dog cat bird]
end
end
def Animal.include?(a)
self.all.include?(a)
end
Animal.include?('cat') # true
Animal.include?('virus') # false
so you can even define methods on the Animal class outside the scope of the class and it will work.
To sum up:
in this example:
module PurchasesHelper
def self.stripe_webhook(event)
#...
end
end
is equal to
module PurchasesHelper
def PurchasesHelper.stripe_webhook(event)
#...
end
end
which is why just adding self allows you to call PurchasesHelper.stripe_webhook

Answer 2

On Koudoku doc's, it says it actually uses stripe_event to handle that https://github.com/integrallis/stripe_event
So, looking on the strip_event examples, you can pass a block and do whatever you need or pass something that respond to the call method https://github.com/integrallis/stripe_event#usage