Question

具有属性更改条件的多个after_update回调仅触发第一个回调。

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

更新模型对象时会触发

method_1：

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

未触发method_2。

Answer 1

您可以使用一个带有if...end块的回调来过滤您希望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

确保检查回调的返回值。如果before_*或after_* ActiveRecord回调返回false，则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回调仅触发第一个回调

2 个答案: