Do something only after the currently open transactions have finished.
Normally everything gets rolled back when a transaction fails, but you cannot roll back sending an email or adding a job to Resque.
gem install ar_after_transaction
class User after_create :do_stuff, :oops def do_stuff after_transaction do send_an_email # cannot be rolled back end comments.create(...) # will be rolled back end def oops raise "do the rolback!" end end
General 'this should be rolled back when in a transaction' code like jobs
class Resque def revertable_enqueue(*args) ActiveRecord::Base.after_transaction do enqueue(*args) end end end
When not in a transaction
after_transaction will perform the given block immediately
Transactional fixtures <-> normally_open_transactions
after_transaction assumes zero open transactions.
If you use transactional fixtures you should change it in test mode.
# spec/rails_helper.rb config.before(:suite) do ActiveRecord::Base.normally_open_transactions = 1 end
Rails 3: after_commit hook can replace the first usage example:
class User after_commit :send_an_email on: :create after_create :do_stuff, :oops ... end
- basic support is built in, use it if you can!
after_commit :bar, on: :create / :update
- after_commit everywhere
- pro: threadsafe
- pro: more fine-grained callbacks (before_commit,
after_commit, before_rollback, after_rollback)
- con: doesn't let you define
after_transactioncallbacks anywhere like
ar_after_transactiondoes (outside of the
after_commit, etc. callbacks which only happen at certain points in the model's life cycle)
- con: more complex
Original idea and code from Jamis Buck (post by Jeremy Kemper)