ruby on rails beginner: rails for zombies code sample

Question

where does that @user in the code in check_ammo come from?
see code for "weapon" in model, controller, mailer and schema.rb

rails for zombies code

Answer 1

That code cant be right. Weaponmailer

  def low_ammo(weapon, zombie)
    attachments["weapon.jpg"] = weapon.picture_file
    mail to: zombie.email, subject: "#{weapon.name} has low ammo"
  end

expects 2 parameters in controller

 WeaponMailer.low_ammo(@user).deliver 

@user is not defined unless its defined in ActiveRecord::Base what is not the case i think. Its just broken code example