另一个编辑：也许是问题的根源？

Question

我似乎无法让state_machine gem（http://github.com/pluginaweek/state_machine/）处理现有记录（它在新记录上正常工作）。

这是我的模特：

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

这是一个IRB会话，它演示了这个问题（我做了ActiveRecord::Base.logger = Logger.new(STDOUT)以便于阅读）：

>> 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publish未保存的评论时，一切正常，但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

即使状态实际发生了变化，state_changed?返回false，因此当我调用save时，Rails不会更新相应的数据库行。

当我关闭部分更新时，它会有效，但在我尝试state_will_change!时则不行：

>> 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"

修改

更奇怪：

>> 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

我在3年后遇到了同样的问题所以值得回答这里以节省其他人的时间。

您需要在表中使用名为“state”的列，因此state_machine将能够使状态持久。

只需将其添加到您的迁移 - t.string：state

即可

Answer 2

是否可以使用发布**！**而非发布

重试状态转换

Answer 3

没有贡献任何有用的东西，但我只想说我在整个应用程序中的多个state_machines中也在努力解决这个错误。我无法切换到AASM，因为我需要在同一个模型中拥有多个state_machine ......太令人沮丧了！

无论如何，你并不孤单，它肯定还需要一个解决方案。

Answer 4

关闭部分更新后是否还会发生这种情况？ Comment.partial_updates = false

如果是这样，那么我们知道问题在于识别脏对象。在拨打c.state_will_change!

之前，您应该可以致电c.publish

Answer 5

模型在初始化时是否调用超级？

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

同样，不是你问题的真实答案，但在这里我试图模拟你的会话：

>> 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"

正如您所看到的，它对我来说是预期的。检查了两次。（我创建了一个带有body和state属性的模型，并将代码放入其中。）

Answer 7

尝试从定义中删除：状态：

FROM： state_machine：state，：initial =＆gt; ：待定

要 state_machine：initial =＆gt; ：待定

state_machine仅适用于新记录

另一个编辑：也许是问题的根源？

7 个答案: