require 'react'

class Timer < React::Component

  def initial_state
    { seconds_elapsed: 0 }
  end

  def tick
    set_state(seconds_elapsed: state[:seconds_elapsed] + 1)
  end

  def component_did_mount
    @interval = window.setInterval(-> { tick }, 1000)
  end

  def component_will_unmount
    window.clearInterval(@interval)
  end

  def render
    div("Seconds Elapsed: #{state[:seconds_elapsed]}")
  end

end

Timer.run