转换为datetime方法切断列表呈现(rails)

我正在使用一个ApplicationHelper方法,在我的视图中将时间对象转换为“人性化”时间度量:

def humanize_seconds s
    if s.nil?
      return ""
    end
    if s > 0
      m = (s / 60).floor
      s = s % 60
      h = (m / 60).floor
      m = m % 60
      d = (h / 24).floor
      h = h % 24
      w = (d / 7).floor
      d = d % 7
      y = (w / 52).floor
      w = w % 52
      output = pluralize(s, "second") if (s > 0)
      output = pluralize(m, "minute") + ", " + pluralize(s, "second") if (m > 0)
      output = pluralize(h, "hour") + ", " + pluralize(m, "minute") if (h > 0)
      output = pluralize(d, "day") + ", " + pluralize(h, "hour") if (d > 0)
      output = pluralize(w, "week") + ", " + pluralize(d, "day") if (w > 0)
      output = pluralize(y, "years") + ", " + pluralize(w, "week") if (y > 0)

      return output
    else
      return pluralize(s, "second")
    end
  end

它工作得很好,但我在翻译一个方法的最终结果时遇到了一个问题,该方法旨在列出指定位置的时间间隔:

RFIDTag.rb:

def time_since_first_tag_use
    product_selections.none? ? "N/A" : Time.now - product_selections.order(staged_at: :asc).first.staged_at
  end 

Product.rb:

def first_staged_tag
  rfid_tags.map { |rfid| rfid.time_since_first_tag_use.to_i }.join(", ")
end

视图:(html.erb):

将值放在那里是可行的,并将值列为 first_staged_tag 本应如此,但仅在几秒钟内完成:

 <% @products.order(created_at: :desc).each do |product| %>
   <td><%= product.name %></td> #Single product name
   <td><%= product.first_staged_tag %></td> list, i.e. #40110596, 40110596, 39680413, 39680324
 <%end%>

以通常的方式转换 <td><%= humanize_seconds(product.first_staged_tag) %></td> ,正如对单个值所做的那样,会出现以下错误:

comparison of String with 0 failed
Extracted source (around line #88):              
86      return ""
87    end
88    if s > 0
89      m = (s / 60).floor
90      s = s % 60
91      h = (m / 60).floor

同时,尝试在产品模型中应用该方法 第一个阶段标签 方法在上生成NoMethod错误 humanize_seconds . 如何获取时间列表以识别时间转换?

所有尝试的重复都在评论中。