Filtering webhook events in chargify

authenticating.rb

before_filter :validate_chargify_webhook
 
def validate_chargify_webhook
  signature = request.headers["X-Chargify-Webhook-Signature-Hmac-Sha-256"].to_s
  body = request.body.read
  computed_signature = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new("sha256"), 
                                               YOUR_CHARGIFY_SITE_KEY, 
                                               body)
  head :unauthorized unless signature == computed_signature
end

filtering.rb

EVENTS_ABOUT_WHICH_WE_CARE = ["payment_success", "billing_date_change"] 

def handle_event
  event = params["event"]
  return head(:ok) unless EVENTS_ABOUT_WHICH_WE_CARE.include?(event)
  # your code here
end

handling.rb

EVENTS_ABOUT_WHICH_WE_CARE = ["payment_success", "billing_date_change"]
 
def handle_event
  event = params["event"]
  payload = params["payload"]
  return head(:unprocessable_entity) if event.blank? || payload.blank?
  return head(:ok) unless EVENTS_ABOUT_WHICH_WE_CARE.include?(event)
  
  self.send(event, payload)  
end
 
private
def payment_success(payload)
    # do things
end

updating.rb

SOME_SUBSCRIPTION_EVENTS = ["payment_success", "billing_date_change"]
 
def handle_event
  event = params["event"]
  payload = params["payload"]
  return head(:unprocessable_entity) unless if event.blank? || payload.blank?
  return head(:ok) unless SOME_SUBSCRIPTION_EVENTS.include?(event)
  
  subscription_id = payload["subscription"]["id"]
  user = User.find_by_subscription_id(subscription_id)
  
  # probably put this in the user model, but it is included here for simplicity
  # this assumes you've already set things up using activeresource
  subscription = Chargify::Subscription.find(self.subscription_id) 
  # "active" is just an example, your model will vary
  user.active = subscription.state == "active" 
  # ... and so on
end