u-observers - 101

u-observers_101.rb

# https://github.com/serradura/u-observers/blob/main/README.pt-BR.md

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'u-observers'
end

class Person
  include Micro::Observers

  attr_reader :name

  def initialize(name)
    @name = name
  end

  def name=(new_name)
    return if @name == new_name
    
    @name = new_name

    observers.notify!(:name_has_been_changed)
  end
end

person = Person.new('Marcelo')

person.observers.on(
  event: :name_has_been_changed,
  with: -> event { event.subject.name },
  call: -> new_name { puts "The person new name is: #{new_name}" }
)

person.name = 'Barbosa'