Grape API + Active Record Wrapping Transaction

Question

We have grape API but I wonder if we can wrap it with active record transaction every time we do request.

In active record to do transaction, we can do something like this:

 ActiveRecord::Base.transaction do
    # do select
    # do update
    # do insert
 end

How can I wrap it into grape API?

As far as i know, in Grape API we can implement before method and after method.

class API < Grape::API
   before do
     # ????? Need to implement code here to begin active record transaction
     # this suppose to begin active record transaction
   end
   after do
     # ????? Need to implement code here to end active record transaction
     # this suppose to end active record transaction
   end
end

Answer 1

Looking at the implementation of transaction block in active record, you should do something like:

class API < Grape::API

  before do
    ActiveRecord::Base.connection.begin_transaction
  end

  after do
    begin
      ActiveRecord::Base.connection.commit_transaction unless @error
    rescue Exception
      ActiveRecord::Base.connection.rollback_transaction
      raise
    end
  end

  rescue_from :all do |e|
    @error = e
    ActiveRecord::Base.connection.rollback_transaction
    # handle exception...
  end

end