6-without-action-mailer.md

Without ActionMailer

As of Caffeinate v2.3.0, you can use Caffeinate without ActionMailer! Internally, these are called "Actions". Here's how to transition from an ActionMailer-based Drip to an Action-based Drip.

Example using ActionMailer

Here's a normal Dripper:

class OnboardingDripper < ApplicationDripper
  self.campaign = :onboarding 
  
  before_drip do |_drip, mailing| 
    if mailing.subscription.subscriber.onboarding_completed?
      mailing.subscription.unsubscribe!("Completed onboarding")
      throw(:abort)
    end 
  end
  
  # map drips to the mailer
  drip :welcome_to_my_cool_app, mailer: 'OnboardingMailer', delay: 0.hours
  drip :some_cool_tips, mailer: 'OnboardingMailer', delay: 2.days
  drip :help_getting_started, mailer: 'OnboardingMailer', delay: 3.days
end

With corresponding OnboardingMailer:

class OnboardingMailer < ActionMailer::Base
  def welcome_to_my_cool_app(mailing)
    @user = mailing.subscriber
    mail(to: @user.email, subject: "Welcome to CoolApp!")
  end

  def some_cool_tips(mailing)
    @user = mailing.subscriber
    mail(to: @user.email, subject: "Here are some cool tips for MyCoolApp")
  end

  def help_getting_started(mailing)
    @user = mailing.subscriber
    mail(to: @user.email, subject: "Do you need help getting started?")
  end
end

To change our drips to a PORO-handled object, we need to:

1. Change each drip option mailer to action_class in OnboardingDripper to OnboardingAction
2. Rename OnboardingMailer to OnboardingAction
3. Have OnboardingAction inherit from Caffeinate::ActionProxy
4. Do something other than mail

1. Change drip option

class OnboardingDripper < ApplicationDripper
  self.campaign = :onboarding 
  
  before_drip do |_drip, mailing| 
    if mailing.subscription.subscriber.onboarding_completed?
      mailing.subscription.unsubscribe!("Completed onboarding")
      throw(:abort)
    end 
  end
  
  # map drips to the mailer
  drip :welcome_to_my_cool_app, action_class: 'OnboardingAction', delay: 0.hours
  drip :some_cool_tips, action_class: 'OnboardingAction', delay: 2.days
  drip :help_getting_started, action_class: 'OnboardingAction', delay: 3.days
end

2. Rename OnboardingMailer

class OnboardingAction < ActionMailer::Base
  def welcome_to_my_cool_app(mailing)
    @user = mailing.subscriber
    mail(to: @user.email, subject: "Welcome to CoolApp!")
  end

  def some_cool_tips(mailing)
    @user = mailing.subscriber
    mail(to: @user.email, subject: "Here are some cool tips for MyCoolApp")
  end

  def help_getting_started(mailing)
    @user = mailing.subscriber
    mail(to: @user.email, subject: "Do you need help getting started?")
  end
end

3. Change subclass

class OnboardingMailer < Caffeinate::ActionProxy
  def welcome_to_my_cool_app(mailing)
    @user = mailing.subscriber
    mail(to: @user.email, subject: "Welcome to CoolApp!")
  end

  def some_cool_tips(mailing)
    @user = mailing.subscriber
    mail(to: @user.email, subject: "Here are some cool tips for MyCoolApp")
  end

  def help_getting_started(mailing)
    @user = mailing.subscriber
    mail(to: @user.email, subject: "Do you need help getting started?")
  end
end

4. Do something different than mail

class OnboardingAction < ActionMailer::Base
  def welcome_to_my_cool_app(mailing)
    @user = mailing.subscriber
    post_to_api(to: @user.phone_number, content: "Welcome to CoolApp!")
  end

  def some_cool_tips(mailing)
    @user = mailing.subscriber
    post_to_api(to: @user.phone_number, content: "Here are some cool tips for MyCoolApp")
  end

  def help_getting_started(mailing)
    @user = mailing.subscriber
    post_to_api(to: @user.phone_number, content: "Do you need help getting started?")
  end
  
  private 
  
  def post_to_api(to:, content:)
    HTTParty.post # ... 
  end
end

Done! Everything is handled the same as it would be otherwise. Caffeinate will still mark them as sent after this action completes successfully.

If you need to bail, raise an error.

Using the actions as setup

If you return an object that implements #deliver!, it will be called. Here's an example:

class PostAPIDeliver
  def initialize(to:, content:)
    @to = to 
    @content = content 
  end
  
  def deliver!(_action)
    HTTParty.post # ...
  end
end

class OnboardingAction < ActionMailer::Base
  def welcome_to_my_cool_app(mailing)
    @user = mailing.subscriber
    post_to_api(to: @user.phone_number, content: "Welcome to CoolApp!")
  end

  def some_cool_tips(mailing)
    @user = mailing.subscriber
    post_to_api(to: @user.phone_number, content: "Here are some cool tips for MyCoolApp")
  end

  def help_getting_started(mailing)
    @user = mailing.subscriber
    post_to_api(to: @user.phone_number, content: "Do you need help getting started?")
  end
  
  private 
  
  def post_to_api(to:, content:)
    PostAPIDeliver.new(to: to, content: content)
  end
end