ruby - Rails 4.1 ActiveRecord::relation 不再像数组

Question

在 Rails 4.0.4 中，这段代码有效:

mailboxes = Mailbox.order(:mailbox)
mailboxes.keep_if do |mailbox|
  # test
end

在 Rails 4.1.0 中它打破了 NoMethodError (undefined method keep_if for <Mailbox::ActiveRecord_Relation:0x5494f80>)

并且必须更改为

mailboxes = Mailbox.order(:mailbox).to_a
mailboxes.keep_if do |mailbox|
  # test
end

没有找到相关信息

有什么想法吗？

Answer 1

它在 release notes 中对于 rails 4.1

Relation no longer has mutator methods like #map! and #delete_if. Convert to an Array by calling #to_a before using these methods. (Pull Request)

因为 keep_if 是一个增变器方法，所以它从 Relation 中移除