Question

我想定义一个after_filter来恢复before_filter的更改，这样所做的更改只会影响我控制器中的一个操作。这是我到目前为止所做的：

before_filter :exclude_root_in_json
after_filter :restore_root_in_json

def exclude_root_in_json
  ActiveRecord::Base.include_root_in_json = false
end

def resotre_root_in_json
  ActiveRecord::Base.include_root_in_json = true
end

我有什么方法可以做以下的事情吗？

def exclude_root_in_json
  default = ActiveRecord::Base.include_root_in_json
  ActiveRecord::Base.include_root_in_json = false
  self.class.after_filter do
    ActiveRecord::Base.include_root_in_json = default
  end
end

我的最终结果是以before_filter调用结束，该调用会在该操作完成后自动撤消该特定操作的更改。我该怎么做？

Answer 1

听起来您可以使用around_filter。查看api文档的此页面：

http://rails.rubyonrails.org/classes/ActionController/Filters/ClassMethods.html

尝试如下：

around_filter :exclude_root_in_json

private
  def exclude_root_in_json
    default = ActiveRecord::Base.include_root_in_json
    ActiveRecord::Base.include_root_in_json = false
    yield
    ActiveRecord::Base.include_root_in_json = default
  end

Rails 3：在before_filter中动态设置after_filter？

1 个答案: