ruby-on-rails - 多次创建调用 before_save

Question

我的模型中有一个 before_save 回调，它在将 2 个字段保存到数据库之前对其进行加密。

class Account < ActiveRecord::Base
  before_save :encrypt_credentials, if: "!username.blank? && !password.blank?"

  def encrypt_credentials
    crypt = ActiveSupport::MessageEncryptor.new(ENV['KEY'])
    self.username = crypt.encrypt_and_sign(username)
    self.password = crypt.encrypt_and_sign(password)
  end

  def decrypted_username
    crypt = ActiveSupport::MessageEncryptor.new(ENV['KEY'])
    crypt.decrypt_and_verify(username)
  end

  def decrypted_password
    crypt = ActiveSupport::MessageEncryptor.new(ENV['KEY'])
    crypt.decrypt_and_verify(password)
  end
end

情况与Devise models run before_save multiple times?非常相似.当我调用 Model.create!(...) - 其中包括需要加密的 2 个字段时，before_save 被调用两次，最终在字段中被加密两次。

Account.create!(
{
  username: ENV['USERNAME'],
  password: ENV['PASSWORD']
})

为什么多次调用before_save？我不喜欢上面链接的帖子的解决方案，我不想先新建/构建再保存。

Answer 1

这是用户错误 :( 在调用 account = Account.create! 之后，我有其他代码调用了 save! 返回模型:account.foo = bar; account.save!。这显然再次调用了 befor_save加密了我的字段。我最终得到了这样的结果:

class Account < ActiveRecord::Base
  before_save :encrypt_username, if: :username_changed?
  before_save :encrypt_password, if: :password_changed?

  def encrypt_username
    crypt = ActiveSupport::MessageEncryptor.new(ENV['KEY'])
    self.username = crypt.encrypt_and_sign(username)
  end

  def encrypt_password
    crypt = ActiveSupport::MessageEncryptor.new(ENV['KEY'])
    self.password = crypt.encrypt_and_sign(password)
  end

  def decrypted_username
    crypt = ActiveSupport::MessageEncryptor.new(ENV['KEY'])
    crypt.decrypt_and_verify(username)
  end

  def decrypted_password
    crypt = ActiveSupport::MessageEncryptor.new(ENV['KEY'])
    crypt.decrypt_and_verify(password)
  end
end