Nil类的未定义方法“+”

Question

我有这样的代码：

<% @accessories.each do |accessory|%>
    <div>
        <%= image_tag(accessory.firebrick_qcg.url , :"title" => accessory.part_number , :"alt" => accessory.description , :"data-size" => accessory.width.to_s + "," + accessory.height , :"data-size2" => accessory.width2.to_s + "," + accessory.height2 , :"data-img1" => accessory.firebrick_qcg.url , :"data-img2" => accessory.firebrick_qcr.url, :"data-img3" => accessory.firebrick_rg.url , class: "img-responsive") %>
    </div>
<% end %>

我得到了一个错误：

ActionView::Template::Error (undefined method `+' for nil:NilClass):

我不知道是怎么回事。如果有人能帮我的话。

Answer 1

我认为连接错误，使用"#{}"连接在ruby中用于字符串。

在保存之前修复空格和额外的行。

<% @accessories.each do |accessory|%>
    <div>
        <%= image_tag(accessory.firebrick_qcg.url, 
        :"title" => accessory.part_number, 
        :"alt" => accessory.description, 
        :"data-size" => "#{accessory.width.to_s}, accessory.height",
        :"data-size2" => "#{accessory.width2.to_s}, #{accessory.height2}", 
        :"data-img1" => accessory.firebrick_qcg.url, 
        :"data-img2" => accessory.firebrick_qcr.url, 
        :"data-img3" => accessory.firebrick_rg.url , 
        class: "img-responsive") %>
    </div>
<% end %>