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Diffstat (limited to 'actionmailbox/lib/action_mailbox/base.rb')
| -rw-r--r-- | actionmailbox/lib/action_mailbox/base.rb | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/actionmailbox/lib/action_mailbox/base.rb b/actionmailbox/lib/action_mailbox/base.rb new file mode 100644 index 0000000000..76c3a4886c --- /dev/null +++ b/actionmailbox/lib/action_mailbox/base.rb @@ -0,0 +1,115 @@ +# frozen_string_literal: true + +require "active_support/rescuable" + +require "action_mailbox/callbacks" +require "action_mailbox/routing" + +module ActionMailbox + # The base class for all application mailboxes. Not intended to be inherited from directly. Inherit from + # `ApplicationMailbox` instead, as that's where the app-specific routing is configured. This routing + # is specified in the following ways: + # + # class ApplicationMailbox < ActionMailbox::Base + # # Any of the recipients of the mail (whether to, cc, bcc) are matched against the regexp. + # routing /^replies@/i => :replies + # + # # Any of the recipients of the mail (whether to, cc, bcc) needs to be an exact match for the string. + # routing "help@example.com" => :help + # + # # Any callable (proc, lambda, etc) object is passed the inbound_email record and is a match if true. + # routing ->(inbound_email) { inbound_email.mail.to.size > 2 } => :multiple_recipients + # + # # Any object responding to #match? is called with the inbound_email record as an argument. Match if true. + # routing CustomAddress.new => :custom + # + # # Any inbound_email that has not been already matched will be sent to the BackstopMailbox. + # routing :all => :backstop + # end + # + # Application mailboxes need to overwrite the `#process` method, which is invoked by the framework after + # callbacks have been run. The callbacks available are: `before_processing`, `after_processing`, and + # `around_processing`. The primary use case is ensure certain preconditions to processing are fulfilled + # using `before_processing` callbacks. + # + # If a precondition fails to be met, you can halt the processing using the `#bounced!` method, + # which will silently prevent any further processing, but not actually send out any bounce notice. You + # can also pair this behavior with the invocation of an Action Mailer class responsible for sending out + # an actual bounce email. This is done using the `#bounce_with` method, which takes the mail object returned + # by an Action Mailer method, like so: + # + # class ForwardsMailbox < ApplicationMailbox + # before_processing :ensure_sender_is_a_user + # + # private + # def ensure_sender_is_a_user + # unless User.exist?(email_address: mail.from) + # bounce_with UserRequiredMailer.missing(inbound_email) + # end + # end + # end + # + # During the processing of the inbound email, the status will be tracked. Before processing begins, + # the email will normally have the `pending` status. Once processing begins, just before callbacks + # and the `#process` method is called, the status is changed to `processing`. If processing is allowed to + # complete, the status is changed to `delivered`. If a bounce is triggered, then `bounced`. If an unhandled + # exception is bubbled up, then `failed`. + # + # Exceptions can be handled at the class level using the familiar `Rescuable` approach: + # + # class ForwardsMailbox < ApplicationMailbox + # rescue_from(ApplicationSpecificVerificationError) { bounced! } + # end + class Base + include ActiveSupport::Rescuable + include ActionMailbox::Callbacks, ActionMailbox::Routing + + attr_reader :inbound_email + delegate :mail, :delivered!, :bounced!, to: :inbound_email + + delegate :logger, to: ActionMailbox + + def self.receive(inbound_email) + new(inbound_email).perform_processing + end + + def initialize(inbound_email) + @inbound_email = inbound_email + end + + def perform_processing + track_status_of_inbound_email do + run_callbacks :process do + process + end + end + rescue => exception + # TODO: Include a reference to the inbound_email in the exception raised so error handling becomes easier + rescue_with_handler(exception) || raise + end + + def process + # Overwrite in subclasses + end + + def finished_processing? + inbound_email.delivered? || inbound_email.bounced? + end + + + def bounce_with(message) + inbound_email.bounced! + message.deliver_later + end + + private + def track_status_of_inbound_email + inbound_email.processing! + yield + inbound_email.delivered! unless inbound_email.bounced? + rescue + inbound_email.failed! + raise + end + end +end |