AASM state machine exception handling example?

I'm currently working on a class, which is basically doing following:

• model gets created
• fetches data (event "get_things!")
  • if exception happens, state should become "failed"
  • if success, state should be "finished"

I try to implement it as following:

class Fetcher < ActiveRecord::Base
  include AASM

  aasm do
    state :created, initial: true
    state :success, :failed

    event :succeed do
      transitions from: :created, to: :success
    end

    event :fail do
      transitions from: :created, to: :failed
    end
  end

  def read_things(throw_exception = false)
    begin
      raise RuntimeError.new("RAISED EXCEPTION") if throw_exception
      self.content = open("http://ift.tt/2qVwIFK").read
      self.succeed!
    rescue => e
      self.fail!
    end
  end
end

a = Fetcher.new
a.fetch!(throw_exception = true)

a = Fetcher.new
a.fetch!(throw_exception = false)

It works, but looks somehow not really good to do...

I would prefer something like the error handling which is mentioned in the readme

event :read_things do
  before do
    self.content = open("http://ift.tt/2qVwIFK").read
    self.succeed!
  end
  error do |e|
    self.fail!
  end
  transitions :from => :created, :to => :success
end

but I dont know if this is really the best practice here?

Any thoughts? Thanks!