def self.find_existing(domain, url_id)
    Article.where(web_domain:domain,url_id:url_id).first
  end

  def content_lines
    if @content_lines.nil?
      regular_exp = /(?:    # Either match...
                      「.*」  # a quoted sentence
                    |         # or
                      [^「」『』。？！]*   # anything except quotes or dots.
                    )+        # Repeat as needed
                    [。？！]\s*     # Then match a dot and optionally some whitespace.
                    /x
      @content_lines = content.scan(regular_exp)
      @content_lines.each do |cl| cl.gsub!(/[[:space:]]/, ' ') end
      @content_lines.each(&:strip!)
    end
    @content_lines
  end

  before_create :build_lines
  def build_lines
    content_lines.each_with_index do |line, index|
      lines.build(text:line, line_number:index+1)
    end
  end