ruby 34 lines · 6 steps

Scheduling a drip email sequence in Rails

An orchestrator declares a timed welcome sequence and enqueues each mailer with the right delay.

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Rails Intermediate mailers background jobs scheduling data-driven design active job
1class WelcomeSequenceOrchestrator
2 STEPS = [
3 { mailer: :welcome_email, delay: 0.hours },
4 { mailer: :getting_started, delay: 1.day },
5 { mailer: :feature_highlights, delay: 3.days },
6 { mailer: :upgrade_nudge, delay: 7.days }
7 ].freeze
8 
9 def initialize(user)
10 @user = user
11 end
12 
13 def call
14 return if @user.unsubscribed_from_onboarding?
15 
16 STEPS.each do |step|
17 enqueue(step[:mailer], step[:delay])
18 end
19 end
20 
21 private
22 
23 def enqueue(mailer_method, delay)
24 job = UserMailer
25 .with(user: @user, sequence: :welcome)
26 .public_send(mailer_method)
27 
28 if delay.zero?
29 job.deliver_later(queue: :mailers)
30 else
31 job.deliver_later(queue: :mailers, wait_until: delay.from_now)
32 end
33 end
34end
01 / 01
STEP 01

Walkthrough

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Three takeaways
  1. 1Encoding a workflow as a frozen data table keeps the schedule readable and easy to reorder.
  2. 2A single guard clause up front lets you skip an entire multi-step sequence for opted-out users.
  3. 3ActiveJob's wait_until turns a relative delay into scheduled delivery without any cron or scheduler.

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