Rails ajax 的联动的下拉框

# app\controllers\examples_controller.rb

ruby 代码

class ExamplesController < ApplicationController

  def ajax_select
    @items = %w{AA BB}
  end

  def get_sub_items
    if params[:item] == "AA"
      @sub_items = %w{AA1 AA2}
    else
      @sub_items = %w{BB1 BB2}
    end

    render :partial => "select"
  end
end

# app\views\examples\ajax_select.rhtml

xml 代码

<%= javascript_include_tag :defaults %>

<h1>Examples#ajax_select</h1>
<p>Find me in app/views/examples/ajax_select.rhtml</p>

<%= select :obj, :att,  @items, {}, :onchange => remote_function(:update => "sub_items",
       :method => "get",
       :with => "'item=' + value",
       :url => { :controller => :examples, :action => :get_sub_items})
       %>
<div id="sub_items">
  <select></select>
</div>

#app\views\examples\_select.rhtml

ruby 代码

<%= select(:obj, :item, @sub_items) %>