How to rescue model transaction and show the user an error?

def exchange_status_with(address)
  ActiveRecord::Base.transaction do
   self.save!
   address.save!
  end
rescue ActiveRecord::RecordInvalid => exception
  # do something with exception here
end

FYI, an exception looks like:

#<ActiveRecord::RecordInvalid: Validation failed: Email can't be blank>

And:

exception.message
# => "Validation failed: Email can't be blank"

Side note, you can change self.save! to save!

Alternate solution if you want to keep your active model errors:

class MyCustomErrorClass < StandardError; end

def exchange_status_with(address)
  ActiveRecord::Base.transaction do
   raise MyCustomErrorClass unless self.save
   raise MyCustomErrorClass unless address.save
  end
rescue MyCustomErrorClass
  # here you have to check self.errors OR address.errors
end