Rails, 销毁后渲染

Question

我有一个 Cart/show.html erb，它呈现一个名为 carts_row.html.erb

的部分

    <p id="notice"><%= notice %></p>

</br>
</br>

<div class="cart-container">
  <%=render 'carts_row'%>
</div>




</p>

在 carts_row 中，它是一个购物车布局，其中包含用于更新购物车中的数量和 destroy/remove 商品的表单。

    <h1>Shopping Cart</h1>

<div class="shopping-cart">
  <div class="column-labels">
    <label class="product-image">Image</label>
    <label class="product-details">Product</label>
    <label class="product-price">Price</label>
    <label class="product-quantity">Quantity</label>

    <!-- adding update column to labels -->
    <label class="product-update">Update</label>
    <label class="product-removal">Remove</label>
    <label class="product-line-price">Total</label>
  </div>

  <%if @cart.cart_items.size == 0%>
  <div class="text-center">
    <p>Looks like you have nothing in your cart! <%=link_to 'Add something to your cart', products_path%></p>
  </div>
  <%end%>

  <br />
  <br />
  <%if @cart_items != nil%>
    <%@cart_items.each do |item|%>

    <div class="product">
      <div class="product-image">
        <%=image_tag(item.product.picture)%>
      </div>
      <div class="product-details">
        <div class="product-title"><%=item.product.name%></div>
        <p class="product-description"><%=item.product.description%></p>
      </div>
      <div class="product-price"><%=number_to_currency(item.product.price)%></div>

      <%=form_for item, remote: true do |f|%>
      <div class="product-quantity">
        <%=f.number_field :quantity, value: item.quantity, min: 1, max: 8%>
        <%=f.hidden_field :product_id, value: item.product.id%>
        <!-- <input type="number" value="<%=item.quantity%>" min="1" max="8"> -->
      </div>
      <div class="product-update">
        <%=f.submit 'Update', class: "update-product"%>
        <!-- <%=f.hidden_field :product_id, value: item.product.id%> -->
        <!-- <button class="update-product">
          Update
        </button> -->
      </div>
      <div class="product-removal">
        <%= link_to "Remove", item, {data: {confirm: "Are you sure you wish to delete the product '#{item.product.name}' from your cart?"}, method: :delete, remote: true, class: "remove-product"}%>
        <!-- <button class="remove-product">
          Remove
        </button> -->
        <%end%>
      </div>
      <div class="product-line-price"><%=number_to_currency(item.product.price*item.quantity)%></div>
    </div>
  <%end%>
  <%end%>
<br />
<br />
<!--Temporary solution until model methods are written  -->
<% if @cart_items != nil%>
  <!--subtotal variable -->
  <%subtotal =@cart_items.collect {|item| item.quantity*item.unit_price}.sum%>
  <!--subtotal + shipping cost  -->
  <%total=subtotal+15%>
<%end%>
<div class="totals">
  <div class="totals-item">
    <label>Subtotal</label>
    <div class="totals-value" id="cart-subtotal"><%=subtotal%></div>
  </div>
  <div class="totals-item">
    <label>Tax (5%)</label>
    <div class="totals-value" id="cart-tax">Included!</div>
  </div>
  <div class="totals-item">
    <label>Shipping</label>
    <div class="totals-value" id="cart-shipping">15.00</div>
  </div>
  <div class="totals-item totals-item-total">
    <label>Grand Total</label>
    <div class="totals-value" id="cart-total">
      <%=total%>
    </div></div>
  </div>
</div>
<div class="checkout-btn">
  <button class="checkout">Checkout</button>
</div>
</div>

表单中的更新转到 update.js.erb 其中有这个

    <% if @cart.errors.any? || @cart_item.errors.any? %>
  alert("Not valid.");
<%else%>
  $(".cart-text").html("<%= escape_javascript(render 'layouts/cart_text')%>")
  $(".cart-container").html("<%= escape_javascript(render 'carts/carts_row')%>")
<%end%>

和destroy的形式一样destroy.js.erb

<% if @cart.errors.any? || @cart_item.errors.any? %>
  alert("Not valid.");
<%else%>
  $(".cart-text").html("<%= escape_javascript(render 'layouts/cart_text')%>")
  $(".cart-container").html("<%= escape_javascript(render 'carts/carts_row')%>")
<%end%>

更新正确呈现 carts_row.html.erb 表单。当我销毁一个项目时，它会在页面底部呈现空产品和结账总额。当我刷新页面时，购物车中显示了正确数量的产品，一切都在它应该在的地方！

怎么update渲染正确，destroy渲染不正确？？？

我的 carts_item 控制器有这两种形式的方法：

  def update
    @cart = current_cart
    # finding cart_items by cart_id
    @cart_item = @cart.cart_items.find(params[:id])
    # @cart_items.order(:id)
    @cart_item.update_attributes(cart_item_params)
    @cart_items = @cart.cart_items.order(:id)
    # redirect 'cart_show_path'
  end

  def destroy
    @cart = current_cart
    @cart_item = @cart.cart_items.find(params[:id])
    @cart_item.destroy
    @cart_items = @cart.cart_items
  end

Answer 1

您正在销毁购物车中的商品，而不是将其从 @cart.cart_items

中移除

尝试这样做

def destroy
  @cart = current_cart
  @cart_item = @cart.cart_items.find(params[:id])

  #Find the index of @cart_item
  item_index = @cart.cart_items.index(@cart_item)

  #Remove it from @cart.cart_items when its destroyed successfully
  if @cart_item.destroy
    @cart.cart_items.delete_at(item_index)
  end

  @cart_items = @cart.cart_items
end

如果有效请告诉我！

Answer 2

我找到问题了。问题是我在我的视图中使用了 <% if @cart_items != nil %> 检查。

这总是 return 错误，因为 ActiveRecord 总是 return 一个数组！！！！！！！！！！ @cart_items对象中是否有产品对象。

在我将此更改为使用 @cart_items.empty? 测试空数组后，页面就按我希望的方式工作了。

感谢 kumar 的意见。

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