rails,json

[view]
<script type="text/javascript">
  (function($){
   $(document).ready(function(){
       var user_id = {};
       user_id['user_id'] = '<%= @user.id %>';

       $.ajax({
          url:  '/people/<%= @user.id %>/books',
          type: 'GET',
          data: user_id,
          dataType: 'json',                     <= 要指定型態
          success:function(data){               <= 出來是個json object array
          $.each(data, function(){
            $('#script').append('<li>'+this.book.name+'</li>');
            });
          }
        });
 
       });
   })(jQuery);
</script>

<ul id='script'></ul>

[controller ]
  def index
    @books = @user.books.find(:all)

    respond_to do |format|
      format.html # index.html.erb
      format.xml  { render :xml => @books.to_xml }
      format.js { render :json => @books.to_json }
      format.yaml  { render :text => @books.to_yaml }
    end
  end