openproject/app/workers/mailer_job.rb

#-- encoding: UTF-8

#-- copyright
# OpenProject is an open source project management software.
# Copyright (C) 2012-2021 the OpenProject GmbH
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 3.
#
# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
# Copyright (C) 2006-2013 Jean-Philippe Lang
# Copyright (C) 2010-2013 the ChiliProject Team
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# See docs/COPYRIGHT.rdoc for more details.
#++

##
# This job gets called when internally using
#
# ```
# UserMailer.some_mail("some param").deliver_later
# ```
#
# because we want to have the sending of the email run in an `ApplicationJob`
# as opposed to using `ActiveJob::QueueAdapters::DelayedJobAdapter::JobWrapper`.
# We want it to run in an `ApplicationJob` because of the shared setup required
# such as reloading the mailer configuration and resetting the request store.
class MailerJob < ApplicationJob
  queue_as { ActionMailer::Base.deliver_later_queue_name }

  # Retry mailing jobs three times with exponential backoff
  retry_on StandardError, wait: :exponentially_longer, attempts: 3

  # If exception is handled in mail handler
  # retry_on will be ignored
  rescue_from StandardError, with: :handle_exception_with_mailer_class

  def perform(mailer, mail_method, delivery, args:)
    mailer.constantize.public_send(mail_method, *args).send(delivery)
  end

  private

  # "Deserialize" the mailer class name by hand in case another argument
  # (like a Global ID reference) raised DeserializationError.
  def mailer_class
    if mailer = Array(@serialized_arguments).first || Array(arguments).first
      mailer.constantize
    end
  end

  def handle_exception_with_mailer_class(exception)
    if klass = mailer_class
      klass.handle_exception exception
    else
      raise exception
    end
  end
end