rails--rails/activemodel/CHANGELOG.md

• Deprecate marshalling load from legacy attributes format.

  Ryuta Kamizono

• *_previously_changed? accepts :from and :to keyword arguments like *_changed?.

  topic.update!(status: :archived)
  topic.status_previously_changed?(from: "active", to: "archived")
  # => true
  

  George Claghorn

• Raise FrozenError when trying to write attributes that aren't backed by the database on an object that is frozen:

  class Animal
    include ActiveModel::Attributes
    attribute :age
  end
  
  animal = Animal.new
  animal.freeze
  animal.age = 25 # => FrozenError, "can't modify a frozen Animal"
  

  Josh Brody

• Add *_previously_was attribute methods when dirty tracking. Example:

  pirate.update(catchphrase: "Ahoy!")
  pirate.previous_changes["catchphrase"] # => ["Thar She Blows!", "Ahoy!"]
  pirate.catchphrase_previously_was # => "Thar She Blows!"
  

  DHH

• Encapsulate each validation error as an Error object.

  The ActiveModel’s errors collection is now an array of these Error objects, instead of messages/details hash.

  For each of these Error object, its message and full_message methods are for generating error messages. Its details method would return error’s extra parameters, found in the original details hash.

  The change tries its best at maintaining backward compatibility, however some edge cases won’t be covered, like errors#first will return ActiveModel::Error and manipulating errors.messages and errors.details hashes directly will have no effect. Moving forward, please convert those direct manipulations to use provided API methods instead.

  The list of deprecated methods and their planned future behavioral changes at the next major release are:

  • errors#slice! will be removed.
  • errors#each with the key, value two-arguments block will stop working, while the error single-argument block would return Error object.
  • errors#values will be removed.
  • errors#keys will be removed.
  • errors#to_xml will be removed.
  • errors#to_h will be removed, and can be replaced with errors#to_hash.
  • Manipulating errors itself as a hash will have no effect (e.g. errors[:foo] = 'bar').
  • Manipulating the hash returned by errors#messages (e.g. errors.messages[:foo] = 'bar') will have no effect.
  • Manipulating the hash returned by errors#details (e.g. errors.details[:foo].clear) will have no effect.

  lulalala

Please check 6-0-stable for previous changes.