Active Job 基础

$ bin/rails generate job guests_cleanup
invoke  test_unit
create    test/jobs/guests_cleanup_job_test.rb
create  app/jobs/guests_cleanup_job.rb

$ bin/rails generate job guests_cleanup --queue urgent

class GuestsCleanupJob < ApplicationJob
  queue_as :default

  def perform(*guests)
    # Do something later
  end
end

$ bin/rails generate job process_payment --parent=payment_job

class ProcessPaymentJob < PaymentJob
  queue_as :default

  def perform(*args)
    # Do something later
  end
end

# Enqueue a job to be performed as soon as the queuing system is
# free.
GuestsCleanupJob.perform_later guest

# Enqueue a job to be performed tomorrow at noon.
GuestsCleanupJob.set(wait_until: Date.tomorrow.noon).perform_later(guest)

# Enqueue a job to be performed 1 week from now.
GuestsCleanupJob.set(wait: 1.week).perform_later(guest)

# `perform_now` and `perform_later` will call `perform` under the hood so
# you can pass as many arguments as defined in the latter.
GuestsCleanupJob.perform_later(guest1, guest2, filter: "some_filter")

# config/application.rb
module YourApp
  class Application < Rails::Application
    # Be sure to have the adapter's gem in your Gemfile
    # and follow the adapter's specific installation
    # and deployment instructions.
    config.active_job.queue_adapter = :sidekiq
  end
end

class GuestsCleanupJob < ApplicationJob
  self.queue_adapter = :resque
  # ...
end

# Now your job will use `resque` as its backend queue adapter, overriding what
# was configured in `config.active_job.queue_adapter`.

class GuestsCleanupJob < ApplicationJob
  queue_as :low_priority
  # ...
end

# config/application.rb
module YourApp
  class Application < Rails::Application
    config.active_job.queue_name_prefix = Rails.env
  end
end

# app/jobs/guests_cleanup_job.rb
class GuestsCleanupJob < ApplicationJob
  queue_as :low_priority
  # ...
end

# Now your job will run on queue production_low_priority on your
# production environment and on staging_low_priority
# on your staging environment

class GuestsCleanupJob < ApplicationJob
  queue_as :low_priority
  self.queue_name_prefix = nil
  # ...
end

# Now your job's queue won't be prefixed, overriding what
# was configured in `config.active_job.queue_name_prefix`.

# config/application.rb
module YourApp
  class Application < Rails::Application
    config.active_job.queue_name_prefix = Rails.env
    config.active_job.queue_name_delimiter = "."
  end
end

# app/jobs/guests_cleanup_job.rb
class GuestsCleanupJob < ApplicationJob
  queue_as :low_priority
  # ...
end

# Now your job will run on queue production.low_priority on your
# production environment and on staging.low_priority
# on your staging environment

class ProcessVideoJob < ApplicationJob
  queue_as do
    video = self.arguments.first
    if video.owner.premium?
      :premium_videojobs
    else
      :videojobs
    end
  end

  def perform(video)
    # Do process video
  end
end

ProcessVideoJob.perform_later(Video.last)

MyJob.set(queue: :another_queue).perform_later(record)

class GuestsCleanupJob < ApplicationJob
  queue_with_priority 10
  # ...
end

class ProcessVideoJob < ApplicationJob
  queue_with_priority do
    video = self.arguments.first
    if video.owner.premium?
      0
    else
      10
    end
  end

  def perform(video)
    # Process video
  end
end

ProcessVideoJob.perform_later(Video.last)

MyJob.set(priority: 50).perform_later(record)

class GuestsCleanupJob < ApplicationJob
  queue_as :default

  around_perform :around_cleanup

  def perform
    # Do something later
  end

  private
    def around_cleanup
      # Do something before perform
      yield
      # Do something after perform
    end
end

class ApplicationJob < ActiveJob::Base
  before_enqueue { |job| $statsd.increment "#{job.class.name.underscore}.enqueue" }
end

# Create jobs to pass to `perform_all_later`.
# The arguments to `new` are passed on to `perform`
guest_cleanup_jobs = Guest.all.map { |guest| GuestsCleanupJob.new(guest) }

# Will enqueue a separate job for each instance of `GuestCleanupJob`
ActiveJob.perform_all_later(guest_cleanup_jobs)

# Can also use `set` method to configure options before bulk enqueuing jobs.
guest_cleanup_jobs = Guest.all.map { |guest| GuestsCleanupJob.new(guest).set(wait: 1.day) }

ActiveJob.perform_all_later(guest_cleanup_jobs)

class ExportDataJob < ApplicationJob
  def perform(*args)
    # Export data
  end
end

class NotifyGuestsJob < ApplicationJob
  def perform(*guests)
    # Email guests
  end
end

# Instantiate job instances
cleanup_job = GuestsCleanupJob.new(guest)
export_job = ExportDataJob.new(data)
notify_job = NotifyGuestsJob.new(guest)

# Enqueues job instances from multiple classes at once
ActiveJob.perform_all_later(cleanup_job, export_job, notify_job)

# If you want to send the email now use #deliver_now
UserMailer.welcome(@user).deliver_now

# If you want to send the email through Active Job use #deliver_later
UserMailer.welcome(@user).deliver_later

I18n.locale = :eo

UserMailer.welcome(@user).deliver_later # Email will be localized to Esperanto.

class TrashableCleanupJob < ApplicationJob
  def perform(trashable_class, trashable_id, depth)
    trashable = trashable_class.constantize.find(trashable_id)
    trashable.cleanup(depth)
  end
end

class TrashableCleanupJob < ApplicationJob
  def perform(trashable, depth)
    trashable.cleanup(depth)
  end
end

# app/serializers/money_serializer.rb
class MoneySerializer < ActiveJob::Serializers::ObjectSerializer
  # Converts an object to a simpler representative using supported object types.
  # The recommended representative is a Hash with a specific key. Keys can be of basic types only.
  # You should call `super` to add the custom serializer type to the hash.
  def serialize(money)
    super(
      "amount" => money.amount,
      "currency" => money.currency
    )
  end

  # Converts serialized value into a proper object.
  def deserialize(hash)
    Money.new(hash["amount"], hash["currency"])
  end

  private
    # Checks if an argument should be serialized by this serializer.
    def klass
      Money
    end
end

# config/initializers/custom_serializers.rb
Rails.application.config.active_job.custom_serializers << MoneySerializer

# config/application.rb
module YourApp
  class Application < Rails::Application
    config.autoload_once_paths << "#{root}/app/serializers"
  end
end

class GuestsCleanupJob < ApplicationJob
  queue_as :default

  rescue_from(ActiveRecord::RecordNotFound) do |exception|
    # Do something with the exception
  end

  def perform
    # Do something later
  end
end

class RemoteServiceJob < ApplicationJob
  retry_on CustomAppException # defaults to 3s wait, 5 attempts

  discard_on ActiveJob::DeserializationError

  def perform(*args)
    # Might raise CustomAppException or ActiveJob::DeserializationError
  end
end