after_commit everywhere

Allows to use ActiveRecord transactional callbacks outside of ActiveRecord models, literally everywhere in your application.

Inspired by these articles:

• https://evilmartians.com/chronicles/rails-after_commit-everywhere
• https://blog.arkency.com/2015/10/run-it-in-background-job-after-commit/

Installation

Add this line to your application's Gemfile:

gem 'after_commit_everywhere'

And then execute:

$ bundle

Or install it yourself as:

$ gem install after_commit_everywhere

Usage

Recommended usage is to include it to your base service class or anything:

class ServiceObjectBtw
  include AfterCommitEverywhere

  def call
    ActiveRecord::Base.transaction do
      after_commit { puts "We're all done!" }
    end
  end
end

Or just extend it whenever you need it:

extend AfterCommitEverywhere

ActiveRecord::Base.transaction do
  after_commit { puts "We're all done!" }
end

Or call it directly on module:

AfterCommitEverywhere.after_commit { puts "We're all done!" }

That's it!

But the main benefit is that it works with nested transaction blocks (may be even spread across many files in your codebase):

include AfterCommitEverywhere

ActiveRecord::Base.transaction do
  puts "We're in transaction now"

  ActiveRecord::Base.transaction do
    puts "More transactions"
    after_commit { puts "We're all done!" }
  end

  puts "Still in transaction…"
end

Will output:

We're in transaction now
More transactions
Still in transaction…
We're all done!

Available callbacks

after_commit

Will be executed right after outermost transaction have been successfully committed and data become available to other DBMS clients.

If called outside transaction will execute callback immediately.

before_commit

Will be executed right before outermost transaction will be commited (I can't imagine use case for it but if you can, please open a pull request or issue).

If called outside transaction will execute callback immediately.

Supported only starting from ActiveRecord 5.0.

after_rollback

Will be executed right after transaction in which it have been declared was rolled back (this might be nested savepoint transaction block with requires_new: true).

If called outside transaction will raise an exception!

Please keep in mind ActiveRecord's limitations for rolling back nested transactions.

Available helper methods

in_transaction?

Returns true when called inside open transaction, false otherwise.

Available callback options

• without_tx allows to change default callback behavior if called without transaction open.

  Available values:

  • :execute to execute callback immediately
  • :warn_and_execute to print warning and execute immediately
  • :raise to raise an exception instead of executing

FAQ

Does it works with transactional_test or DatabaseCleaner

Yes.

Be aware of mental traps

While it is convenient to have after_commit method at a class level to be able to call it from anywhere, take care not to call it on models.

So, DO NOT DO THIS:

class Post < ActiveRecord::Base
  def self.bulk_ops
    find_each do
      after_commit { raise "Some doesn't expect that this screw up everything, but they should" }
    end
  end
end

By calling the class level after_commit method on models, you're effectively adding callback for all Post instances, including future ones.

See https://github.com/Envek/after_commit_everywhere/issues/13 for details.

But what if I want to use it inside models anyway?

In class-level methods call AfterCommitEverywhere.after_commit directly:

class Post < ActiveRecord::Base
  def self.bulk_ops
    find_each do
       AfterCommitEverywhere.after_commit { puts "Now it works as expected!" }
    end
  end
end

For usage in instance-level methods include this module to your model class (or right into your ApplicationRecord):

class Post < ActiveRecord::Base
  include AfterCommitEverywhere

  def do_some_stuff
    after_commit { puts "Now it works!" }
  end
end

However, if you do something in models that requires defining such ad-hoc transactional callbacks, it may indicate that your models have too many responsibilities and these methods should be extracted to separate specialized layers (service objects, etc).

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install.

Releasing new versions

1. Bump version number in lib/after_commit_everywhere/version.rb

   In case of pre-releases keep in mind rubygems/rubygems#3086 and check version with command like Gem::Version.new(AfterCommitEverywhere::VERSION).to_s

2. Fill CHANGELOG.md with missing changes, add header with version and date.

3. Make a commit:

   git add lib/after_commit_everywhere/version.rb CHANGELOG.md
   version=$(ruby -r ./lib/after_commit_everywhere/version.rb -e "puts Gem::Version.new(AfterCommitEverywhere::VERSION)")
   git commit --message="${version}: " --edit
   

4. Create annotated tag:

   git tag v${version} --annotate --message="${version}: " --edit --sign
   

5. Fill version name into subject line and (optionally) some description (list of changes will be taken from CHANGELOG.md and appended automatically)

6. Push it:

   git push --follow-tags
   

7. GitHub Actions will create a new release, build and push gem into rubygems.org! You're done!

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Envek/after_commit_everywhere.

License

The gem is available as open source under the terms of the MIT License.