如何获得此代码以不断循环遍历各个项目？

Question

I have the following code:

common_load_help("photo.xml");
function common_load_help(file)
{
  $(document).ready(function()
  {
    $.ajax(
    {
      type: "GET",
      url: SITE_URL + "/assets/help/" + file, //call this url
      dataType: 'xml',
      success: function(xml) //when we have the data...
      {
        var length = xml.getElementsByTagName("item").length;
        console.log("length: " + length);
        $('item', xml).each(function(i, el) //go through each help item
        {
          function looper()
          {
            $("#design-tips-content").html($(el, this).text());
          }
          setTimeout(looper, 5000);
        });

      }
    });
  });
}

What I would like to happen is it puts the 1st element in the design-tips-content div, then wait 5000 seconds, then put the 2nd, then put the 3rd, then loop back to the first element. How would I go about doing that? Right now it just seems like it is just showing the last element.

Note: I tried to create a jsfiddle for this ( http://jsfiddle.net/allisonc/c8RLZ/ ) but I get the error: MLHttpRequest cannot load http://www.asa.tframes.org:1881/assets/help/photo.xml. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://fiddle.jshell.net' is therefore not allowed access. MLHttpRequest cannot load http://www.asa.tframes.org:1881/assets/help/photo.xml. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://fiddle.jshell.net' is therefore not allowed access.

Answer 1

This code inside the success function should work. It works by building an array of the items' text, and storing the current index value in a variable. Then, it uses setInterval to continually loop through all the items.

var tips = $('item', xml).get().map(function(item){
    return $(item).text();
});

var currentIndex = 0;

function looper() {
    if(currentIndex>=tips.length) {
        currentIndex = 0;
    }
    $('#design-tips-content').html(tips[currentIndex]);
    currentIndex++;
}

looper();
setInterval(looper, 5000);

Working fiddle