具有属性更改条件的多个 after_update 回调仅触发第一个

Question

具有属性更改条件的多个 after_update 回调仅触发第一个。

class Article < ActiveRecord::Base
  after_update :method_1, :if => proc{ |obj| obj.status_changed? && obj.status == 'PUBLISHED' }
  after_update :method_2, :if => proc{ |obj| obj.status_changed? && obj.status == 'PUBLISHED' && obj.name == 'TEST' }
  ...
end

method_1 更新模型对象时触发：

Article.last.update_attributes(status: 'PUBLISHED', name: 'TEST')

虽然method_2没有被触发。

Answer 1

您可以只使用一个带有 if...end 块的回调来过滤您想要在每种情况下执行的操作。

class Article < ActiveRecord::Base
  after_update :method_1, :if => proc{ |obj| obj.status_changed? && obj.status == 'PUBLISHED' }
  ...

  def method_1        
    if self.name == 'TEST'
      # stuff you want to do on method_2
    else
      # stuff you want to do on method_1
    end
  end
end

Answer 2

确保检查回调的 return 值。如果 before_* 或 after_* ActiveRecord 回调 return 为 false，链中的所有后续回调都将被取消。

来自 docs（请参阅取消回调）

If a before_* callback returns false, all the later callbacks and the associated action are cancelled. If an after_* callback returns false, all the later callbacks are cancelled.

具有属性更改条件的多个 after_update 回调仅触发第一个

Multiple after_update callbacks with attribute change conditions are triggering only the first one

activerecord

ruby-on-rails

ruby-on-rails-3

ruby-on-rails-3.1