I have my transactional email system setup & by default people get emails as events happen:
class Comment
after_create :email_original_poster
def email_original_poster
UserMailer.delay.notify_author_of_comment self
end
end
However instead of getting the email as-it-happens, a chunk of my users would prefer a daily or weekly digest.
What's the cleanest most elegant way to implement this?
I've already got delayed_job running but this doesn't really feel like a delayed_job job since I'm queueing data that needs to be acted on rather than actions that need to be executed.
...without reinventing a queueing system
I know that the obvious solution is table of queued_emails and of course I could do that. The reason I'm asking the question is that to do so is reinventing a queueing system. Not only are there lots of queuing systems out there but as this well worded post from Percona points out, it's a good idea not to roll your own:
Have you implemented a digest email, did you use delayed_job & what did you learn?
A digest looks like more appropriate to be done as a cron job like. You would still have to control to "who you have sent", to deal with crashes and errors, but the idea is to run, for example, on a daily basis, a custom rake task that craft your mail message including all info in a digest format and them send or queue for sending.
Obviously you shouldn't have to create your own queueing system. I haven't used delayed_job, but I have used resque in conjunction with a nice little gem called resque_mailer that should do exactly what you want. What's nice about resque_mailer is that, once it's set up, you don't have to change how you'd normally send mail: MyMailer.some_mailing({vars}).deliver If for some reason you want to not use the queue to send the mail (send it right away), you just need to add ! after deliver and it'll do just that.
Look into resque (with redis) and resque_mailer, I think it'll do what you want.
In case anyone wants more details on a great way to do this, there's a good overview here (second answer): Sending emails based on intervals using Ruby on Rails
来源：https://stackoverflow.com/questions/7589059/whats-the-most-elegant-way-to-implement-a-digest-email-without-reinventing-a-qu