我有自己相关的表：

id | data | owner_id
1  | A    | null
2  | B    | 1
3  | C    | 1
4  | D    | 2

因此​​，因此B和C属于A和D属于B。

So therefore B and C belong to A and D belongs to B.

我的问题是我怎么能在Rails 3视图中显示一个链接的选择框，如果选择数据，然后出现另一个选择框与它的孩子，当你选择出现另一个选择框一个孩子其子等使用Ajax？

My question is how can I display in a Rails 3 view a chained select box where if you select a "data" then another select box appears with its "children" and when you select one of the children another select box appears with its children and so forth using Ajax?

例如在previous表，如果我选择一个，在选择框中将出现另一个选择框显示B和C，如果我选择B.将出现另一个选择框显示ð。

For example in the previous table if I select A in the select box another select box would appear showing B and C and if I select B another select box would appear showing D.

非常感谢你。

推荐答案

有2种方式，你可以处理这个

There are 2 ways you could approach this

添加一个onchange事件，你的第一个字段，它会调用一个方法，在您的控制器，以获取相关的选项和填充的第二选择菜单。

Add an onchange event to your first field which would call a method in your controller to fetch the relevant options and populate the second select menu.

刚刚得知，有一个名为 ChainSelects 插件，试图做到这一点。你可以尝试一下。 （我想preFER做我自己，但它给你。）

Just learned that there's a plugin called ChainSelects that attempts to do this. You could try it out. (I would prefer to do it myself, but its up to you.)

有一个 Railscast 解释这项技术的细节。虽然这railscast使用Rails的2.3，您可以使用该技术，并定制了对Rails 3。

There's a Railscast that explains this technique in detail. Even though this railscast uses Rails 2.3 you can use the technique and customize it for Rails 3.