ruby-on-rails - Rails3 中的 before_create、before_update、before_save、before_destroy 弃用警告

Question

我刚刚将我的应用程序从 Rails 2.3 升级到 3，我得到了一些
我的 before_create、update、save、destroy 等的弃用警告。

有谁知道如何解决这个问题？

这些是我的警告:

DEPRECATION WARNING: Base#before_create has been deprecated, please use Base.before_create :method instead. (called from /Users/macmini/qna/app/models/user.rb:32)
DEPRECATION WARNING: Base#before_update has been deprecated, please use Base.before_update :method instead. (called from /Users/macmini/qna/app/models/user.rb:40)
DEPRECATION WARNING: Base#after_save has been deprecated, please use Base.after_save :method instead. (called from /Users/macmini/qna/app/models/user.rb:50)
DEPRECATION WARNING: Base#before_destroy has been deprecated, please use Base.before_destroy :method instead. (called from /Users/macmini/qna/app/models/user.rb:56)

只是 before_create 的一个例子:

  def before_create
    self.username.downcase!
    self.salt = User.make_salt(self.username)
    self.hashed_password = User.hash_with_salt(@password, self.salt)
  end

Answer 1

您看到的警告是 Rails 3 试图阻止您覆盖基础 before_*和 after_*方法。这与您拥有 before_filter 的方式类似和 Controller 中的其他回调。

这意味着，而不是做:

def before_create
  self.username.downcase!
  self.salt = User.make_salt(self.username)
  self.hashed_password = User.hash_with_salt(@password, self.salt)
end

Rails 希望你这样做:

before_create :downcase_username_and_create_password

def downcase_username_and_create_password
  self.username.downcase!
  self.salt = User.make_salt(self.username)
  self.hashed_password = User.hash_with_salt(@password, self.salt)
end

在这种情况下，您甚至可以将两者分开，因为您可能希望独立生成密码:

before_create :downcase_username, :create_password

def downcase_username
  self.username.downcase!
end

def create_password
  self.salt = User.make_salt(self.username)
  self.hashed_password = User.hash_with_salt(@password, self.salt)
end