ruby-on-rails - has_many autosave_associated_records_for_*

Question

我正在尝试关联现有记录，同时仍然能够添加新记录。以下不起作用，但非常接近我需要的。如何完成关联现有记录和创建新记录？

has_many :comments, :through => :commentings, :source => :commentable, :source_type => "Comment"
accepts_nested_attributes_for :comments, :allow_destroy => true

def autosave_associated_records_for_comments
  comments.each do |comment|
    if existing_comment = Comment.find_by_fax_and_name(comment.fax, comment.name)
      self.comments.reject! { |hl| hl.fax == existing_comment.fax && hl.name == existing_comment.name }
      self.comments << existing_comment
    else
      self.comments << comment
    end
  end
end

这是相关的源代码行:https://github.com/rails/rails/blob/v3.0.11/activerecord/lib/active_record/autosave_association.rb#L155

Answer 1

我已经制定了解决方案，但如果您知道更好的方法，请告诉我!

def autosave_associated_records_for_comments
  existing_comments = []
  new_comments = []

  comments.each do |comment|
    if existing_comment = Comment.find_by_fax_and_name(comment.fax, comment.name)
      existing_comments << existing_comment
    else
      new_comments << comment
    end
  end

  self.comments << new_comments + existing_comments
end