Retryable transaction

gistfile1.rb

class ActiveRecord::Base
 
  # Retryable transaction
  # =====================
  # 
  # Author : Bastien Gysler (http://www.bastiengysler.com)
  #
  #   ActiveRecord::Base.retryable_transaction(tries: 1, :when => ActiveRecord::RecordNotUnique) do |on|
  #     on.transaction do
  #        # transaction code here
  #     end
  #     on.success do
  #        # success code here
  #     end
  #     on.error do |ex|
  #       # error code here
  #     end
  #   end
  #
  def self.retryable_transaction(args = {}, &block)
    retries = args[:tries] || 1
    begin
      self.transaction do
        block.callback :transaction
      end

      block.callback :success
    rescue args[:when] || ActiveRecord::Errors => e
      retry if (retries -= 1) >= 0

      block.callback :error, e
    end    
  end
end
 
 
# Author : Mat Sears (http://mattsears.com/)
class Proc
  def callback(callable, *args)
    self === Class.new do
      method_name = callable.to_sym
      define_method(method_name) { |&block| block.nil? ? true : block.call(*args) }
      define_method("#{method_name}?") { true }
      def method_missing(method_name, *args, &block) false; end
    end.new
  end
end