关于用Rails构建购物车/结帐的问题。

I just picked up Agile Web Development with Rails 3rd Ed., and I'm going thru the Depot Application chapters, and I have a question about Product/Item options-

我刚刚学习了敏捷Web开发，Rails是第3版，我将通过仓库应用程序章节，我有一个关于产品/项目选项的问题

If I wanted to modify the product catalog and store so that products could have options (size, color, whatever), where/how would I do that?

如果我想修改产品目录和存储，使产品可以有选项(大小、颜色等等)，我应该在哪里/如何做呢?

Let's say I'm selling t-shirts, and they come in different sizes. I don't feel like that's something that really needs a model created to handle sizes, so I thought I could just add it as a select box in the html in the store's view.

假设我在卖t恤，它们有不同的尺寸。我不觉得这真的需要一个模型来处理大小，所以我想我可以把它作为一个选择框添加到商店视图的html中。

But, each Add to Cart button is wrapped by a form tag that is automatically generated by button_to, and doesn't seem to give me the ability to pass additional parameters to my cart. How can I get the size of the item added into the POST to add_to_cart?

但是，每个Add to Cart按钮都是由一个由button_to自动生成的表单标记包装的，而且似乎不能给我传递额外参数到我的购物车的能力。如何获得添加到add_to_cart的邮件的大小?

And perhaps more importantly- what is the most Railsy way to do so?

也许更重要的是——最可笑的做法是什么?

Thanks in advance for any help! --Mark

感谢您的帮助!——马克。

The helper in my view:

在我看来帮助者:

<%= button_to "Add to Cart" , :action => :add_to_cart, :id => product %>

The form that it generates:

它产生的形式:

<form method="post" action="/store/add_to_cart/3" class="button-to">

4 个解决方案

#1

Ok, it's 2 days later, and I figured it out. This is what I had to do-

好的，两天后，我算出来了。这是我必须做的。

1, in my store view:

<% form_for @product, :url => {:action => "add_to_cart", :id => @product} do |f| %>
  <select name="productsize" id="productsize">
    <option value="L">L</option>
    <option value="XL">XL</option>
  </select>
  <%= f.submit 'Add to Cart' %>
<% end %>

2, added to my store controller:

productsize = params[:productsize]
@cart.add_product(product, productsize)

Had to get productsize from params, and then pass it with the rest of the product model to the cart model's add_product action.

必须从params获取产品大小，然后将产品模型的其余部分传递给cart模型的add_product操作。

3, adjusted the cart model to accept the argument, and:

@items << CartItem.new(product, productsize)

Passed it along with the rest of the product model to create a new Cart Item and add it to items.

将它与产品模型的其余部分一起传递，以创建新的Cart项并将其添加到items中。

4, added to the cart_item model:

attr_reader :product, :quantity, :productsize

def initialize(product, productsize)
@product = product
@productsize = productsize

to read in productsize and initialize Cart Item.

读取productsize并初始化Cart项。

5, added to my add_to_cart view:

Size: <%=h item.productsize %>

To display it for the user.

以显示给用户。

That's it. If there is an easier or DRYer way to go about it, I'm all ears (eyes?).

就是这样。如果有一种更简单或更干的方式，我会全神贯注(眼睛?)

#2

I'm not sure why you wouldn't store size, unless what you mean is that you'd store size as part of cart_item rather than product, which would be fine. In that case you'd do something like this:

我不确定为什么不存储大小，除非您的意思是您将大小存储为cart_item而不是product的一部分，这样很好。在这种情况下，你会这样做:

<% form_for(@cart_item) do |f| %>
<%= f.select :size, ['S', 'M', 'L', 'XL', 'XXL'] %>
<%= f.hidden_field :product_id, :value => @product.id %> 
# other properties...
<%= f.submit 'Add to Cart' %>
<% end %>

#3

I'd drop the button_to helper and use a proper form, submitting the product properties to the add_to_cart action.

我将删除button_to helper，并使用适当的表单，将产品属性提交给add_to_cart操作。

<% form_for(@product) do |f| %>
<%= f.select :size, ['S', 'M', 'L', 'XL', 'XXL'] %>
# other properties...
<%= f.submit 'Add to Cart' %>
<% end %>

#4

You will need to add attributes to your model. For that, you will need to create a migration to update your database table. I only have the 2nd edition of the book, but there's a section called "Iteration A2: Add a missing column" that describes how to do this. I assume a similar section would be in the 3rd edition.

您将需要向模型添加属性。为此，需要创建迁移来更新数据库表。我只有这本书的第二版，但是有一个章节叫做“迭代A2:添加一个缺失的列”，描述了如何做到这一点。我想在第三版中也会有类似的章节。

After doing that, you can follow Can Berk Güder's suggestion and replace the button by a form.

这样做之后，您可以按照can Berk Guder的建议，用表单替换按钮。