在Rails上验证有限状态机(使用AASM)

gem 'aasm'

class Order< ApplicationRecord
  include AASM

  aasm do
    state :pending, initial: true
    state :processing
    state :shipped
    state :delivered
  end
end

aasm do
  state :pending, initial: true
  state :processing
  state :shipped
  state :delivered

  event :process do
    transitions from: :pending, to: :processing
  end

  event :ship do
    transitions from: :processing, to: :shipped
  end

  event :deliver do
    transitions from: :shipped, to: :delivered
  end
end

def process_order
  @order = Order.find(params[:id])
  @order.process!
  redirect_to @order
end

def ship_order
  @order = Order.find(params[:id])
  @order.ship!
  redirect_to @order
end

def deliver_order
  @order = Order.find(params[:id])
  @order.deliver!
  redirect_to @order
end

aasm do
  state :pending, initial: true
  state :processing
  state :shipped
  state :delivered

  event :process do
    transitions from: :pending, to: :processing, guard: :payment_received?
  end

  event :ship do
    transitions from: :processing, to: :shipped, guard: :all_items_in_stock?
  end

  event :deliver do
    transitions from: :shipped, to: :delivered, guard: :package_received?
  end
end

def payment_received?
  # 检查支付是否已收到
end

def all_items_in_stock?
  # 检查所有物品是否都有库存
end

def package_received?
  # 检查包裹是否已收到
end