Ruby on rails 如果顺序为零，则重定向或呈现页面

如果找不到订单，我将尝试渲染。页面未重定向，我收到错误信息：

找不到订单，未定义nil:NilClass的“shopify_name”方法

我的看法是：

<h1>Cancel Your Order Here</h1>

 <h3 style="color: white;">YOUR ORDER NUMBER IS <%= @order.shopify_name %></h3>
        <div id="multiple-file-preview">
          <div class="card-body">
            <% if @order.cancelled? %>
              <h5>YOUR ORDER HAS BEEN CANCELLED SUCCESSFULLY!</b> <br><br>Please contact our customer service for further information on <b>info@mrswordsmith.com</b></h5>
            <% elsif @order.scheduled? %>
              <%= link_to('Cancel',
                order_path(@order.shopify_id), class: 'btn btn-danger',
                  data: {
                    disable_with: "Order Cancelled"
                  }, method: :delete)
                %>
            <% else %>
              <h5>As you are attempting to cancel outside of the 2 hour cancellation window, please contact our customer support team</b></h5>
            <% end %>

当我试图更改url中的订单号时，它给了我一个错误提示：

`shopify_name'代表nil:NilClass。我想知道如何在屏幕上渲染 同一页

---

我不完全确定你想做什么，但是

如果您希望在@order存在时呈现“取消”视图，否则重定向，则控制器操作将如下所示：

def cancel
  @order = Order.find_by(shopify_id: params[:id])

  unless @order
    flash[:alert] = 'Order not found'
    redirect_to root_path # or wherever you want them to go if order doesn't exist
  end

  # render will happen automatically, is default behavior
end

def cancel
  @order = Order.find_by(shopify_id: params[:id])

  unless @order
    flash.now[:alert] = 'Order not found'
    render :new # render the new view with the cancel url
  end
end

如果要在找不到顺序的情况下使用相同的URL呈现不同的视图，可以执行以下操作：

def cancel
  @order = Order.find_by(shopify_id: params[:id])

  unless @order
    flash[:alert] = 'Order not found'
    redirect_to root_path # or wherever you want them to go if order doesn't exist
  end

  # render will happen automatically, is default behavior
end

def cancel
  @order = Order.find_by(shopify_id: params[:id])

  unless @order
    flash.now[:alert] = 'Order not found'
    render :new # render the new view with the cancel url
  end
end

---

您需要在控制器中渲染或重定向，@order正在设置。@dinjas嗨，我已经更新了我的cotrollerhi@dinjas谢谢您的回答，这真的很有帮助！如果我想在同一页上渲染，如果我能做些什么呢？我不知道你说的在同一页上渲染是什么意思。您可以添加一个条件。。。。。。。这就是你的意思吗？