使用jQuery解析烦人的Youtube API XML提要

时间:2010-07-02 03:10:06

标签: xml jquery youtube-api

我正在学习如何在Intranet中使用外部XML Feed,以便更好地为我们的员工服务,并减少他们离开网络寻找内容的需求。

我可以毫无问题地从Feed中呈现基本信息。我来的地方是试图显示一个视频缩略图,作为我选择的布局的一部分。

问题

我试图从第一个URL元素中获取media:thumbnail属性的值,以便在img标记中使用,但无论我尝试什么,我似乎都无法渲染内容它的。

EG; <media:thumbnail url='http://i.ytimg.com/vi/CQP_AuT4zXQ/default.jpg'... />

我要提取的文字&amp;以上示例中的使用是http://i.ytimg.com/vi/CQP_AuT4zXQ/default.jpg

我怀疑为什么我无法解析此元素的值与其中包含句点(:)分隔符的元素名称有关,和/或我对jQuery的开发知识怀疑我没有调用或试图正确解析这个元素或其中的一部分。

我也想渲染media:keywords的值,这可以通过理解相同的问题来解决。

用于呈现XML的代码

<script type="text/javascript">
/* learned from http://www.switchonthecode.com/tutorials/xml-parsing-with-jquery */
/* this can be used to parse any file in an XML format */
$(document).ready(function()
{
/*
perform an asynchronous ajax request using the relevant variables
Documentation: http://api.jquery.com/jQuery.ajax/
*/
  $.ajax({
    type: "GET",
    /* define url of xml file to parse */
    url: "/pr/rss_repository/youtube.xml",
    /* assign it a data type */
    dataType: "xml",
    /* state name of function to run if file is successfully parsed */
    success: parseXml
  });
});
function parseXml(xml)
/* this is where the xml file is parsed and converted into a HTML output */
{

  //for each item node in the xml file
  $(xml).find("item").each(function()
  {
  //print the following html, inserting the relevant data within the nodes of item
    //this is the heading
    $("#output").append("<h2><a href=\"" + $(this).find("link").text() + "\" target=\"_blank\"> " + $(this).find("title").text() + "</a></h2>\n");
//this is a new paragraph with the publication date
    $("#output").append("<p>" + $(this).find("pubDate").text() + "</p>\n");
//this is the description text of the item
$("#output").append("<p>" + $(this).find("description").text() + "</p>\n");
$("#output").append("<p><img src=\"" + $(this).find("media:thumbnail").text() + "\"></p>\n");
  });
 //end for each
//end function
}
</script>

结果HTML

<h2><a href="http://www.youtube.com/watch?v=CQP_AuT4zXQ&amp;feature=youtube_gdata" target="_blank"> IFA World Forestry Day 2010 forum - Bob Pearce, FIFWA (Part 1)</a></h2>
<p>Thu, 01 Apr 2010 06:44:19 +0000</p>
<p>Bob Pearce, Executive Director - Forest Industries Federation of Western Australia delivers a presentation on the impact of timber harvesting in healthy forests at the Institute of Foresters of Australia 2010 World Forestry Day forum.</p>
<p><img src=""></p>
...

正在解析Youtube的XML示例

该文件被抓取并带入我们的服务器,以便在每次调用时保存正在下载的文件。我们使用VBScript将其拉入网络,该VBScript转储从查询的URL返回的内容。

来自http://gdata.youtube.com/feeds/api/videos?alt=rss&author=fpcwa的数据示例:

<?xml version='1.0' encoding='UTF-8'?>
<rss xmlns:atom='http://www.w3.org/2005/Atom' xmlns:media='http://search.yahoo.com/mrss/' xmlns:openSearch='http://a9.com/-/spec/opensearch/1.1/' xmlns:gd='http://schemas.google.com/g/2005' xmlns:gml='http://www.opengis.net/gml' xmlns:yt='http://gdata.youtube.com/schemas/2007' xmlns:georss='http://www.georss.org/georss' version='2.0'>
  <channel>
    ... standard channel description
    <item>
      <guid isPermaLink='false'>tag:youtube.com,2008:video:CQP_AuT4zXQ</guid>
      <pubDate>Thu, 01 Apr 2010 06:44:19 +0000</pubDate>
      <atom:updated>2010-04-29T00:03:31.000Z</atom:updated>
      <category domain='http://schemas.google.com/g/2005#kind'>http://gdata.youtube.com/schemas/2007#video</category>
      <category domain='http://gdata.youtube.com/schemas/2007/categories.cat'>News</category>
      <category domain='http://gdata.youtube.com/schemas/2007/keywords.cat'>ifa</category>
      ... remaining categories
      <title>IFA World Forestry Day 2010 forum - Bob Pearce, FIFWA (Part 1)</title>
      <link>http://www.youtube.com/watch?v=CQP_AuT4zXQ&feature=youtube_gdata</link>
      <author>fpcwa</author>
      <yt:accessControl action='comment' permission='allowed'/>
      ...
      <gd:comments>
        <gd:feedLink href='http://gdata.youtube.com/feeds/api/videos/CQP_AuT4zXQ/comments?client=ytapi-google-jsdemo' countHint='0'/>
      </gd:comments>
      <media:group>
        <media:category label='News & Politics' scheme='http://gdata.youtube.com/schemas/2007/categories.cat'>News</media:category>
        <media:content url='http://www.youtube.com/v/CQP_AuT4zXQ?f=videos&c=ytapi-google-jsdemo&app=youtube_gdata' type='application/x-shockwave-flash' medium='video' isDefault='true' expression='full' duration='587' yt:format='5'/>
        <media:content url='rtsp://v1.cache6.c.youtube.com/CjcLENy73wIaLgl0zfjkAv8DCRMYDSANFEITeXRhcGktZ29vZ2xlLWpzZGVtb0gGUgZ2aWRlb3MM/0/0/0/video.3gp' type='video/3gpp' medium='video' expression='full' duration='587' yt:format='1'/>
        <media:content url='rtsp://v2.cache3.c.youtube.com/CjcLENy73wIaLgl0zfjkAv8DCRMYESARFEITeXRhcGktZ29vZ2xlLWpzZGVtb0gGUgZ2aWRlb3MM/0/0/0/video.3gp' type='video/3gpp' medium='video' expression='full' duration='587' yt:format='6'/>
        <media:credit role='uploader' scheme='urn:youtube'>fpcwa</media:credit>
        <media:description type='plain'>Bob Pearce, Executive Director - Forest Industries Federation of Western Australia delivers a presentation on the impact of timber harvesting in healthy forests at the Institute of Foresters of Australia 2010 World Forestry Day forum.</media:description>
        <media:keywords>ifa, institute of foresters, australia, forestry, world forestry day, 2010, forum, healthy forests, forest, forests, bob pearce, fifwa</media:keywords>
        <media:player url='http://www.youtube.com/watch?v=CQP_AuT4zXQ&feature=youtube_gdata'/>
        <media:thumbnail url='http://i.ytimg.com/vi/CQP_AuT4zXQ/default.jpg' height='90' width='120' time='00:04:53.500'/>
        <media:thumbnail url='http://i.ytimg.com/vi/CQP_AuT4zXQ/2.jpg' height='90' width='120' time='00:04:53.500'/>
        <media:thumbnail url='http://i.ytimg.com/vi/CQP_AuT4zXQ/1.jpg' height='90' width='120' time='00:02:26.750'/>
        <media:thumbnail url='http://i.ytimg.com/vi/CQP_AuT4zXQ/3.jpg' height='90' width='120' time='00:07:20.250'/>
        <media:thumbnail url='http://i.ytimg.com/vi/CQP_AuT4zXQ/hqdefault.jpg' height='360' width='480'/>
        <media:title type='plain'>IFA World Forestry Day 2010 forum - Bob Pearce, FIFWA (Part 1)</media:title>
        <yt:aspectRatio>widescreen</yt:aspectRatio>
        <yt:duration seconds='587'/>
        <yt:uploaded>2010-04-01T06:44:19.000Z</yt:uploaded>
        <yt:videoid>CQP_AuT4zXQ</yt:videoid>
      </media:group>
      <yt:statistics favoriteCount='0' viewCount='10'/>
    </item>

2 个答案:

答案 0 :(得分:5)

完全不同的方法是以JSON-C格式而不是Atom XML请求您的YouTube API结果:

http://code.google.com/apis/youtube/2.0/developers_guide_jsonc.html

您应该可以通过JavaScript代码更轻松地找到结果。

答案 1 :(得分:2)

这是jQuery中的一个错误,它不支持处理XML命名空间。您可以采用以下两种方法之一:

.find("[nodeName=media:thumbnail]")
.find("media\\:thumbnail]")

大多数人推荐第一个,因为第二个在某些WebKit版本下不起作用。

如果您需要更多详细信息或其他替代方法,请在网络上搜索"jquery find namespace"

更新:要获取ulr节点上media:thumbnail属性的值,请使用以下命令:

.attr("url")