state_machine 仅适用于新记录

Question

我似乎无法获得 state_machine gem (http://github.com/ pluginaweek/state_machine/) 来处理现有记录（它可以在新记录上正常工作）。

这是我的模型：

class Comment < ActiveRecord::Base
  state_machine :state, :initial => :pending do
    event :publish do
      transition all => :published
    end
  end
end

这是一个演示该问题的 IRB 会话（我做了 ActiveRecord::Base.logger = Logger.new(STDOUT) 以使其更易于阅读）：

>> c = Comment.new
=> #<Comment id: nil, song_id: nil, author: nil, body: nil, created_at: nil, updated_at: nil, state: "pending">
>> c.state
=> "pending"
>> c.publish
  Comment Create (0.6ms)   INSERT INTO "comments" ("updated_at", "body", "author", "song_id", "created_at", "state") VALUES('2009-11-02 02:44:37', NULL, NULL, NULL, '2009-11-02 02:44:37', 'published')
=> true
>> Comment.last.state
  Comment Load (0.4ms)   SELECT * FROM "comments" ORDER BY comments.id DESC LIMIT 1
=> "published"
>> c = Comment.create
  Comment Create (0.5ms)   INSERT INTO "comments" ("updated_at", "body", "author", "song_id", "created_at", "state") VALUES('2009-11-02 02:44:47', NULL, NULL, NULL, '2009-11-02 02:44:47', 'pending')
=> #<Comment id: 4, song_id: nil, author: nil, body: nil, created_at: "2009-11-02 02:44:47", updated_at: "2009-11-02 02:44:47", state: "pending">
>> c.publish
=> true
>> c.save
=> true
>> Comment.last.state
  Comment Load (0.4ms)   SELECT * FROM "comments" ORDER BY comments.id DESC LIMIT 1
=> "pending"

即，当我发布未保存的评论，但是当我尝试发布已保存的评论时，没有任何反应。

另一个编辑：也许是问题的根源？

=> true
>> a = Comment.last
  Comment Load (1.3ms)   SELECT * FROM "comments" ORDER BY comments.id DESC LIMIT 1
=> #<Comment id: 3, song_id: nil, author: nil, body: nil, created_at: "2009-11-03 03:03:54", updated_at: "2009-11-03 03:03:54", state: "pending">
>> a.state
=> "pending"
>> a.publish
=> true
>> a.state
=> "published"
>> a.state_changed?
=> false

即，即使状态实际上已经改变，state_changed? 返回 false，因此 Rails 不会更新相应的数据库行当我调用save时。

当我关闭部分更新时它有效，但当我尝试 state_will_change! 时它不起作用：

>> Comment.partial_updates = false
=> false
>> c = Comment.create
  Comment Create (0.5ms)   INSERT INTO "comments" ("updated_at", "body", "author", "song_id", "created_at", "state") VALUES('2009-11-07 05:06:49', NULL, NULL, NULL, '2009-11-07 05:06:49', 'pending')
=> #<Comment id: 7, song_id: nil, author: nil, body: nil, created_at: "2009-11-07 05:06:49", updated_at: "2009-11-07 05:06:49", state: "pending">
>> c.publish
  Comment Update (0.9ms)   UPDATE "comments" SET "created_at" = '2009-11-07 05:06:49', "author" = NULL, "state" = 'published', "body" = NULL, "song_id" = NULL, "updated_at" = '2009-11-07 05:06:53' WHERE "id" = 7
=> true
>> Comment.last.state
  Comment Load (0.5ms)   SELECT * FROM "comments" ORDER BY comments.id DESC LIMIT 1
=> "published"
>> Comment.partial_updates = true
=> true
>> c = Comment.create
  Comment Create (0.8ms)   INSERT INTO "comments" ("updated_at", "body", "author", "song_id", "created_at", "state") VALUES('2009-11-07 05:07:21', NULL, NULL, NULL, '2009-11-07 05:07:21', 'pending')
=> #<Comment id: 8, song_id: nil, author: nil, body: nil, created_at: "2009-11-07 05:07:21", updated_at: "2009-11-07 05:07:21", state: "pending">
>> c.state_will_change!
=> "pending"
>> c.publish
=> true
>> c.save
=> true
>> Comment.last.state
  Comment Load (0.5ms)   SELECT * FROM "comments" ORDER BY comments.id DESC LIMIT 1
=> "pending"

编辑：

更多怪异：

>> a = Comment.last
  Comment Load (1.2ms)   SELECT * FROM "comments" ORDER BY comments.id DESC LIMIT 1
=> #<Comment id: 5, song_id: nil, author: nil, body: nil, created_at: "2009-11-02 06:33:19", updated_at: "2009-11-02 06:33:19", state: "pending">
>> a.state
=> "pending"
>> a.publish
=> true
>> a.state
=> "published"
>> a.save
=> true
>> a.id
=> 5
>> Comment.find(5).state
  Comment Load (0.3ms)   SELECT * FROM "comments" WHERE ("comments"."id" = 5) 
=> "pending"

比较：

>> a = Comment.last
  Comment Load (0.3ms)   SELECT * FROM "comments" ORDER BY comments.id DESC LIMIT 1
=> #<Comment id: 5, song_id: nil, author: nil, body: nil, created_at: "2009-11-02 06:33:19", updated_at: "2009-11-02 06:33:19", state: "pending">
>> a.state = "published"
=> "published"
>> a.save
  Comment Update (0.6ms)   UPDATE "comments" SET "state" = 'published', "updated_at" = '2009-11-02 08:29:34' WHERE "id" = 5
=> true
>> a.id
=> 5
>> Comment.find(5).state
  Comment Load (0.4ms)   SELECT * FROM "comments" WHERE ("comments"."id" = 5) 
=> "published"

Answer 1

三年后我遇到了同样的问题，所以值得在这里回答以节省其他人的时间。

您需要在表中包含名为“state”的列，以便 state_machine 能够使状态持久化。

只需将其添加到您的迁移中 - t.string :state

Answer 2

您可以使用publish**!**而不是publish重试状态转换吗

Answer 3

没有贡献任何有用的东西，但我只是想说，在整个应用程序的多个 state_machines 中，我也在努力解决这个错误。而且我无法切换到 AASM，因为我需要在同一模型中拥有多个 state_machine...太令人沮丧了！

不管怎样，你并不孤单，它肯定还需要一个解决方案。

Answer 4

关闭部分更新后还会发生这种情况吗？ Comment.partial_updates = false

如果是这样，那么我们就知道问题出在识别脏对象上。您应该能够在调用 c.publish 之前调用 c.state_will_change!

Answer 5

模型初始化时是否调用 super ？

state_machine 文档说状态需要初始化

def initialize
  @seatbelt_on = false
  super() # NOTE: This *must* be called, otherwise states won't get initialized
end

Answer 6

再说一遍，这不是对您问题的真正答案，但在这里我尝试模拟您的会话：

>> c = Comment.new
=> #<Comment id: nil, body: nil, created_at: nil, updated_at: nil, state: "pending">
>> c.state
=> "pending"
>> c.publish
=> true
>> Comment.last.state
=> "published"
>> c = Comment.create
=> #<Comment id: 4, body: nil, created_at: "2009-11-05 07:12:53", updated_at: "2009-11-05 07:12:53", state: "pending">
>> c.publish
=> true
>> c.save
=> true
>> Comment.last.state
=> "published"

如您所见，它对我来说按预期工作。检查了两次。
（我创建了一个具有主体和状态属性的模型，并将您的代码放入其中。）

Answer 7

尝试从定义中删除 :state:

FROM:
state_machine：状态，：初始=> ：待

处理
状态机：初始=> ：待办