How to raise an ActiveRecord::Rollback exception and return a value together?

You could store the value you want returned from the function in a variable and return that outside the transaction block. E.g.

  def save_with_place_in_set(parent_id)    return_value = false    Category.transaction do      if !save_without_place_in_set        return_value = false      elsif !validate_move parent_id        return_value = false        raise ActiveRecord::Rollback      else        place_in_nested_set parent_id        return_value = true      end    end    return return_value  end

I've set the return_value to false initially as the only other way you can get out of that transaction block is if one of the other methods raises ActiveRecord::Rollback I believe.

Because the ActiveRecord::Rollback exception is handled, but not re-raised by ActiveRecord::Transaction, I could move my return out of the transaction block, and thus return a value after the transaction is rolled back.

With a little refactoring:

def save_with_place_in_set(parent_id = nil)  Category.transaction do    return false if !save_without_place_in_set    raise ActiveRecord::Rollback if !validate_move parent_id    place_in_nested_set parent_id    return true  end  return falseend

I know it may be a little late, but i ran into the same problem and just found out, that within a transaction block you can simply raise an Exception and rescue that one...Rails implicitly rollbacks the whole transaction. So there is no need for ActiveRecord::Rollback.

For example:

def create  begin    Model.transaction do      # using create! will cause Exception on validation errors      record = Model.create!({name: nil})      check_something_afterwards(record)      return true    end  rescue Exception => e    puts e.message    return false  endenddef check_something_afterwards(record)  # just for demonstration purpose  raise Exception, "name is missing" if record.name.nil?end

I'm working with Rails 3.2.15 and Ruby 1.9.3.