ruby-on-rails - 如何在不调用依赖 : :destroy on associations 的情况下销毁 Rails 模型

Question

有没有一种方法可以销毁 Rails 模型，而无需为关联中的 dependent::destroy 调用回调。

例子:

class Administration < ActiveRecord::Base
  include IdentityCache

  attr_accessible :auto_sync, :response_rate_calc_state, :description,
    :year, :project_id, :season, :auto_async, :synchronized_at

  has_many :report_distributions 
  has_many :rosters, dependent: :destroy

  before_destroy :delete_file

  attr_accessible :file

  has_attached_file :file,
      path: ":class/:id_partition/:basename.:extension",
      storage: :s3,
      bucket: S3Config::AWS_BUCKET_MODELS,
      s3_credentials: {
          access_key_id: S3Config::AWS_ACCESS_KEY_ID_MODELS,
          secret_access_key: S3Config::AWS_SECRET_ACCESS_KEY_MODELS
      },
      s3_permissions: 'authenticated-read',
      s3_protocol: 'https',
      s3_storage_class: :reduced_redundancy

  def authenticated_url(style = nil, expires_in = 10.seconds)
    file.s3_object(style).url_for(:read, secure: true, expires: expires_in).to_s
  end

  def delete_file
    file.s3_object(nil).delete if self.file?
  end

# ...

所以当我打电话

Administration.find(id).destroy

我只想删除记录和附件，但不要调用删除rosters的回调

has_many :rosters, dependent: :destroy

--

PS 我不想禁用 has_many :rosters, dependent: :destroy。我只需要暂时禁用回调。

Answer 1

您可以保持关联不变，并通过以下方式之一跳过回调:

1. 使用delete 而不是 destroy 因为它 won't fire callbacks

Administration.find(id).delete

2. 使用skip_callback 方法(在 blog post 中找到):

 Administration.skip_callback(:destroy, :bofore, :action_you_need_to_disable)
 #then safely destroy without firing the action_you_need_to_disable callback
 Administration.find(id).destroy

3. 或者更好的是，如果您已经知道什么时候需要跳过回调，您可以这样做:

class Admistration < ActiveRecord::Base
  has_many :rosters, dependent: :destroy
  skip_callback :destroy, :before, :action_you_need_to_disable, if: -> { #conditions }
end

链接:api docs on skip_callback