aasm/README_FROM_VERSION_3_TO_4.md

Migrating from AASM version 3 to 4

Must

after_commit hooks are now event-based

The after_commit hooks have been move from the state level to the event level. So, if you want some code block to be executed after the AASM state has been saved AND committed, change this code

class Job < ActiveRecord::Base
  include AASM

  aasm do
    state :sleeping, :initial => true
    state :running, :after_commit => :notify_about_running_job

    event :run do
      transitions :from => :sleeping, :to => :running
    end
  end

  def notify_about_running_job
    ...
  end
end

to

class Job < ActiveRecord::Base
  include AASM

  aasm do
    state :sleeping, :initial => true
    state :running

    event :run, :after_commit => :notify_about_running_job do
      transitions :from => :sleeping, :to => :running
    end
  end

  def notify_about_running_job
    ...
  end
end

Could

Triggering an event without to_state

When providing parameters to callbacks it is not required to provide the to_state anymore. So, assuming you have the following class:

class Job
  include AASM

  aasm do
    state :sleeping, :initial => true
    state :running

    event :run do
      transitions :from => :sleeping, :to => :running, :after => :log
    end
  end

  def log(message)
    logger.info message
  end
end

then you could change from

job = Job.new
job.run(:running, "we want to run")

to this:

job = Job.new
job.run("we want to run")

job.run(:running, "we want to run") # still supported to select the target state (the _to_state_)

New configuration option: no_direct_assignment

If you want to make sure that the AASM column for storing the state is not directly assigned, configure AASM to not allow direct assignment, like this:

class Job < ActiveRecord::Base
  include AASM

  aasm :no_direct_assignment => true do
    state :sleeping, :initial => true
    state :running

    event :run do
      transitions :from => :sleeping, :to => :running
    end
  end

end

resulting in this:

job = Job.create
job.aasm_state # => 'sleeping'
job.aasm_state = :running # => raises AASM::NoDirectAssignmentError
job.aasm_state # => 'sleeping'