增加Ajax按钮导轨

I'm having trouble for this button:

controller

class ProductsController < ApplicationController

def test

@product = Product.find(params[:my][:id])
@k = params[:my][:k]
@product.update_attribute :amount, @product.amount + @k.to_i
respond_to do |format|
  format.js 
  format.html
end
end
def product_params
  params.require(:product).permit(:amount)
end

view:

<% @products.each do |product| %>
<td class="ajax">
        <%= product.amount %>
</td>
<td><%= link_to '+1', {controller: 'products', action: 'test', 
            my: {id: product.id, k: '1'}}, 
            :method => :post, :remote => true, 
            class: "btn btn-info btn-xs" %>
</td>

test.js.erb:

$(".ajax").html("<%= @product.amount %>")

routes:

resources :products
post 'products/test'

when I press the button, every product is updated with the value of product corrisponding to the button, refreshing the page every value is correct. Someone can help me?

I bet all of your products have css class ajax. Try to use id instead.

Edit:

Your view:

<% @products.each do |product| %>
  <td id="product-<%= product.id %>">
    <%= product.amount %>
  </td>
  <td>
    <%= link_to '+1', {controller: 'products', action: 'test', 
              my: {id: product.id, k: '1'}}, 
              :method => :post, :remote => true, 
              class: "btn btn-info btn-xs" %>
  </td>
<% end %>

test.js.erb:

$("#product-<%= @product.id %>").html("<%= @product.amount %>")