如何显示的link_to助手仅当它返回> 0

Question

我有这样的帮手链接

link_to "", product_path(product, anchor: "disqus_thread"), data: { "disqus-identifier" => "#{url_for([product, {only_path: false}])}" }, class: "no-underline bold grey-text text-darken-3 margin-left" 

布局：application.rb中

%script{id: "dsq-count-scr", src: "https://url.disqus.com/count.js", async: "async"} 

_disqus.html.erb

<div class="col-lg-8 col-lg-offset-2 big-top-space margin-bottom"> 
    <div id="disqus_thread"></div> 
    <script> 
    var disqus_shortname = 'yourname'; 
    var disqus_identifier = '<%= url_for([product, {only_path: false}]) %>'; 
    var disqus_title = '<%= product.name %>'; 
    var disqus_url = '<%= url_for([product, {only_path: false}]) %>'; 
    (function() { // DON'T EDIT BELOW THIS LINE 
    var d = document, s = d.createElement('script'); 
    s.src = 'https://url.disqus.com/embed.js'; 
    s.setAttribute('data-timestamp', +new Date()); 
    (d.head || d.body).appendChild(s); 
    })(); 
</script> 
<noscript>Please enable JavaScript to view the <a href="https://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript> 

</div> 

和所有工作正常我得到一个数字，数量是在我的索引视图中每个职位的disqus评论计数器，但如何显示数字如果是否大于0？如果等于0我不想在视图中显示它。有人知道如何解决这个问题？非常感谢

我试着用这样的：

此列添加到产品COMMENT_COUNT：整数

我改变了我的_disqus.html

<div class="col-lg-8 col-lg-offset-2 big-top-space margin-bottom"> 
     <div id="disqus_thread"></div> 
     <script> 
     var disqus_shortname = 'yourname'; 
     var disqus_identifier = '<%= url_for([product, {only_path: false}]) %>'; 
     var disqus_title = '<%= product.name %>'; 
     var disqus_url = '<%= url_for([product, {only_path: false}]) %>'; 

     var disqus_config = function() { 
    this.callbacks.onNewComment = [ 
     function() {   
     $.ajax({ 
      method: "PATCH", 
      url: '<%= product_path(product) %>', 
      data: {increment: "comment_count"} 
     }) 
     } 
    ]; 
}; 
     (function() { // DON'T EDIT BELOW THIS LINE 
     var d = document, s = d.createElement('script'); 
     s.src = 'https://url.disqus.com/embed.js'; 
     s.setAttribute('data-timestamp', +new Date()); 
     (d.head || d.body).appendChild(s); 
     })(); 
    </script> 
    <noscript>Please enable JavaScript to view the <a href="https://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript> 

    </div> 

Product_controller

def update  
    product = Product.find(params[:id]) 
    product.update(update_product) 
    end 
def update_product 
    params.permit(:comment_count) 
end  

来源：https://help.disqus.com/customer/portal/articles/466258-capturing-disqus-commenting-activity-via-callbacks

，但我得到这个错误

Started PATCH "/products/12" for ::1 at 2017-04-12 17:44:38 -0500 
Processing by ProductsController#update as */* 
Parameters: {"increment"=>"comment_count", "id"=>"12"} 
ShoppingCart Load (0.0ms) SELECT "shopping_carts".* FROM "shopping_carts" WH 
ERE "shopping_carts"."id" = ? LIMIT 1 [["id", 102]] 
Product Load (0.0ms) SELECT "products".* FROM "products" WHERE "products"."i 
d" = ? LIMIT 1 [["id", 12]] 
CACHE (0.0ms) SELECT "products".* FROM "products" WHERE "products"."id" = ? 
LIMIT 1 [["id", "12"]] 
Unpermitted parameters: increment, id 
(0.0ms) begin transaction 
User Load (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 
1 [["id", 1]] 
(0.0ms) commit transaction 
Rendered products/update.haml within layouts/application (0.0ms) 
(0.0ms) SELECT COUNT(*) FROM "products" INNER JOIN "in_shopping_carts" ON "p 
roducts"."id" = "in_shopping_carts"."product_id" WHERE "in_shopping_carts"."shop 
ping_cart_id" = ? [["shopping_cart_id", 102]] 
Rendered partials/_unlogged.haml (15.5ms) 
Rendered partials/_nav.haml (765.8ms) 
Completed 200 OK in 3476ms (Views: 3448.8ms | ActiveRecord: 0.0ms) 

不允许的参数：增量，ID

控制台

COMMENT_COUNT：无

有人能帮助我吗？

Answer 1

我能想到的解决这一点的最好办法是：

• 一个comment_count属性添加到您的数据库
• 添加disqus onNewComment回调来更新你的记录注释计数。

用JavaScript您可以添加一个回调：

var disqus_config = function() { 
    this.callbacks.onNewComment = [ 
     function() { 
     alert(comment.id); 
     alert(comment.text); 
     $.ajax({ 
      method: "PATCH", 
      url: "<%= product_path(product) %>", 
      data: {increment: "comment_count"} 
     }) 
     } 
    ]; 
}; 

，那么你会知道的评论数向前发展。

文档：https://help.disqus.com/customer/portal/articles/466258-capturing-disqus-commenting-activity-via-callbacks

更改您的控制器到：

def update  
    product = Product.find(params[:id]) 
    if params[:comment_count] 
    product.increment!(:comment_count) 
    else 
    product.update(update_product) 
    end 
end 

Answer 2

你不能 - 至少不能以你尝试的方式。

link_to "", product_path(product, anchor: "disqus_thread"), data: { "disqus-identifier" => "#{url_for([product, {only_path: false}])}" }, class: "no-underline bold grey-text text-darken-3 margin-left" 

在页面发送到浏览器之前，在Rails服务器上对此进行评估。

<script> 
    var disqus_shortname = 'yourname'; 
    var disqus_identifier = '<%= url_for([product, {only_path: false}]) %>'; 
    var disqus_title = '<%= product.name %>'; 
    var disqus_url = '<%= url_for([product, {only_path: false}]) %>'; 
    (function() { // DON'T EDIT BELOW THIS LINE 
    var d = document, s = d.createElement('script'); 
    s.src = 'https://url.disqus.com/embed.js'; 
    s.setAttribute('data-timestamp', +new Date()); 
    (d.head || d.body).appendChild(s); 
    })(); 
</script> 

这个JavaScript是在客户端（用户的浏览器）后运行 - 在这一点上的页面由服务器已经发出。

如果您想知道在服务器端渲染时是否有任何注释，您需要从服务器拨打Disqus API。