activerecord 枚举和脏属性

Question

我有一个定义 enum 的模型，如下所示：

enum status: [ :init, :requested, :packed, :paid, :shipped ]

我还有以下使用脏属性的方法。

  def shipment_requested
    status_changed?(from: :init, to: :requested)
  end

  def shipment_packed
    status_changed?(from: :requested, to: :packed)
  end

  def shipment_paid
    status_changed?(from: :packed, to: :paid)
  end

  def shipment_shipped
    status_changed?(from: :paid, to: :shipped)
  end

有很多依赖于此的模型回调，例如更新时间戳和发送电子邮件。

但不幸的是，这些都不起作用。

sh = Shipment.find(1)
sh.init?
=> true
sh.requested!
sh.requested?
=> true
sh.shipment_requested
=> false

上面的代码有什么问题？这是一个错误吗？

我本可以在控制器上手动设置所有值，但这违背了使用枚举的目的，根据上面的文档，枚举具有非常好的特性，比如定义范围和方法来检查status

Answer 1

尝试将值作为字符串发送到changed? 方法：

class Entry < ApplicationRecord
  enum type: [:single, :double, :triple]
end

e = Entry.first
e.type # => "single"
e.type = :double
# notice here values are strings, not symbols
e.type_change # => ["single", "double"]
e.type_changed?(from: :single, to: :double) # => false
e.type_changed?(from: "single", to: "double") # => true