Rails link_to_remote无法渲染，为什么？

Question

RoR新手在这里。在Agile Web Dev with Rails的第9章结束时使用“play time”练习。无法获取link_to_remote以在部分中为我生成链接。我store_cart_item.html.erb部分看起来像这样：

<% if cart_item == @current_item then %> 
    <tr id="current_item"> 
<% else %> 
    <tr> 
<% end %> 
    <td> 
<!-- stuck here, trying to get a link to decrement the quantity, but it doesn't 
    even show a link, I also tried nesting a link_to in form_remote_tag which 
    at least displayed link but didn't call the remove_from_cart action --> 
<% link_to_remote cart_item.quantity.to_s + "&times;", 
       :update => "cart", 
       :url => {:action => "remove_from_cart", :id => cart_item.product} %> 
</td> 
<td><%= h cart_item.title %></td> 
<td class="item-price"><%= number_to_currency(cart_item.price) %></td> 
</tr> 

在浏览器中，link_to_remote似乎无所事事，B/C HTML输出如下：

<tr> 
    <td> 
    <!-- stuck here, trying to get a stupid link to decrement the quantity, doesn't even show link 
    also tried nesting it in form_remote_tag which at least displayed link but didn't call the 
    remove_from_cart action --> 
</td> 
<td>Agile Web Development with Rails</td> 
<td class="item-price">$68.85</td> 
</tr> 

感觉就像我错过了非常明显的事情我究竟做错了什么？

Answer 1

标签<% exp %>下的表达式仅被评估，不分配值。

，如果你想使用或显示表达式的值只使用“=”号像

<%= exp %> 

你的代码只是改变

<%= link_to_remote cart_item.quantity.to_s + "&times;", 
       :update => "cart", 
       :url => {:action => "remove_from_cart", :id => cart_item.product} %> 

Answer 2

使用<%= link_to_remote ... %>而不是<% link_to_remote %>（假设您使用的是rails 2.x或以前的版本）。