retryable_record

Gem | Source | Documentation

Retries an operation on an ActiveRecord until no StaleObjectError is being raised.

You can use retryable_record in 3 different ways:

require 'retryable_record'

RetryableRecord.retry(user) do
  user.username = "foo"
  user.save!
end

require 'retryable_record/import'

RetryableRecord(user) do
  user.username = "foo"
  user.save!
end

require 'retryable_record'

class User < ActiveRecord::Base
  include RetryableRecord
end

user = User.first

user.retryable do
  user.username = "foo"
  user.save!
end

There is also an option attempts to limit the number of retries. If no attempts option is specified, it's assumed to be possibly infinte attempts until an ActiveRecord::StaleObjectError is not raised. The attempts option works in all three forms.

Here is the Module inclusion example with an attempts option used.

require 'retryable_record'

class User < ActiveRecord::Base
  include RetryableRecord
end

user = User.first

user.retryable(:attempts => 5) do
  user.username = "foo"
  user.save!
end

After 5 attempts, this will just re-raise the ActiveRecord::StaleObjectError anyway.

ActiveRecord migration needs to support optimistic locking. See http://api.rubyonrails.org/classes/ActiveRecord/Locking/Optimistic.html

class CreateUsers < ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.string :name
      t.integer :lock_version

      t.timestamps
    end
  end
end

Inspired by

• http://blog.codefront.net/2008/01/14/retrying-code-blocks-in-ruby-on-exceptions-whatever/
• http://github.com/nfedyashev/retryable
• http://vision-media.ca/resources/ruby/better-ruby-retryable-method (broken)

Thanks to all contributions from awesome people!

• Improve README example
• Add Changelog!
• Intergration test with ActiveRecord

• Fork the project.
• Make your feature addition or bug fix.
• Add tests for it. This is important so I don't break it in a future version unintentionally.
• Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
• Send me a pull request. Bonus points for topic branches.