Question

我正在使用购物车构建应用。但是，我无法从购物车中删除商品。 Items，Line_items和Carts有资源。他们有这种关系：

class Cart < ActiveRecord::Base
has_many :line_items
has_one :order
end

class LineItem < ActiveRecord::Base
belongs_to :cart
belongs_to :item
end

我可以像这样在购物车中添加商品：

<% for item in @items %>
      <%= link_to "Add to Cart", line_items_path(:item_id => item), :method => :post, class: "btn" %>
 <% end %>

这将调用line_items控制器中的create方法：

def create
@item = Item.find(params[:item_id])
@line_item = LineItem.create!(:cart => current_cart, :item => @item, :quantity => 1)
flash[:notice] = "Added #{@item.name} to sample."
redirect_to root_path
end

以下是问题的要点：我无法弄清楚如何从购物车中删除东西。我可以通过运行以下命令删除控制台中的line_item：

cart = Cart.last
cart.line_items.destroy(9)

如何在应用中实现此功能？这种方法的控制器是什么？我正在努力让这个工作：

<% for line_item in @cart.line_items %>
       <%= link_to 'Remove', line_item, method: :delete %>
<% end %>

我已经尝试在carts_controller和line_items_controller中定义它，但无济于事。我的基本问题是：如何将某些内容从控制台转换为应用文件？

以下是路线：

 line_items GET    /line_items(.:format)           line_items#index
                          POST   /line_items(.:format)           line_items#create
            new_line_item GET    /line_items/new(.:format)       line_items#new
           edit_line_item GET    /line_items/:id/edit(.:format)  line_items#edit
                line_item GET    /line_items/:id(.:format)       line_items#show
                          PATCH  /line_items/:id(.:format)       line_items#update
                          PUT    /line_items/:id(.:format)       line_items#update
                          DELETE /line_items/:id(.:format)       line_items#destroy
                    items GET    /items(.:format)                items#index
                          POST   /items(.:format)                items#create
                 new_item GET    /items/new(.:format)            items#new
                edit_item GET    /items/:id/edit(.:format)       items#edit
                     item GET    /items/:id(.:format)            items#show
                          PATCH  /items/:id(.:format)            items#update
                          PUT    /items/:id(.:format)            items#update
                          DELETE /items/:id(.:format)            items#destroy
                   orders GET    /orders(.:format)               orders#index
                          POST   /orders(.:format)               orders#create
                new_order GET    /orders/new(.:format)           orders#new
               edit_order GET    /orders/:id/edit(.:format)      orders#edit
                    order GET    /orders/:id(.:format)           orders#show
                          PATCH  /orders/:id(.:format)           orders#update
                          PUT    /orders/:id(.:format)           orders#update
                          DELETE /orders/:id(.:format)           orders#destroy
                     root GET    /                               items#index
                   thanks GET    /thanks(.:format)               pages#thanks
                          DELETE /carts/:id(.:format)            cart#remove_item
                    carts GET    /carts(.:format)                carts#index
                          POST   /carts(.:format)                carts#create
                 new_cart GET    /carts/new(.:format)            carts#new
                edit_cart GET    /carts/:id/edit(.:format)       carts#edit
                     cart GET    /carts/:id(.:format)            carts#show
                          PATCH  /carts/:id(.:format)            carts#update
                          PUT    /carts/:id(.:format)            carts#update

Answer 1

<强>破坏

您问题的直接答案是将其置于destroy控制器的line_items操作中：

<% for line_item in @cart.line_items %>
       <%= link_to 'Remove', line_item, method: :delete %> #-> will take you to  destroy path
<% end %>

这将带您：

#app/controllers/line_items_controller.rb
Class LineItemsController < ApplicationController
   def destroy
      @line_item = LineItem.find params[:id]
      @line_item.destroy
   end
end

-

<强>集合

处理问题的更有效方法是从collection删除记录。这需要更多的努力，但是完全值得：

#config/routes.rb
resources :cart, except: :destroy do
    collection do
       delete ":id", to: "cart#remove_item" #-> DELETE domain.com/cart/56
    end
end

#app/controllers/cart_controller.rb
class CartController < ApplicationController
   def remove_item
      current_cart.line_items.delete params[:id]
   end
end

Answer 2

你在line_items控制器中有一个destroy方法。该网址将与您编码的一样......

<%= link_to 'Remove', line_item, method: :delete %>

我建议使用button_to＆＃39;添加到购物车＆＃39;如果你想让它们看起来像按钮。

单击它应该调用正确的控制器和操作。

class LineItemsController < ApplicationController

  def destroy
    @line_item = LineItem.find(params[:id])
    @line_item.destroy
    # Then redirect to the index or render the js view
  end

end

如何将Rails控制台转换为App控制器和视图

2 个答案: