解析位于<img>提要项的<description></description>中的rss2标记

Question

我试图实现的是使用RSS2提要项的src属性。提要的xml项如下所示：

<item>
  <title>BlackBerry EMEA servers crash</title>
  <link>http://www.mysite.com/?p=672</link>
  <comments>http://www.mysite.com/?p=672#comments</comments>
  <pubDate>Mon, 10 Oct 2011 21:11:24 +0000</pubDate>
  <dc:creator>acreator</dc:creator>
  <category><![CDATA[Latest News]]></category>
  <description><![CDATA[<span class="image-rss"><a href="http://www.mysite.com/?p=672"><img title="BlackBerry EMEA servers crash" src="http://www.mysite.com/wp-content/uploads/2011/10/blackberry-thumb-medium-300x187.jpg" alt="BlackBerry EMEA servers crash" width="200" height="124" /></a></span><br/>yada yada yada]]></description>
</item>

我目前使用的代码很好地解析了<description>、<title>、<link>和<pubdate>；但是在<img>上失败了。以下是代码：

NSArray *channels = [rootElement elementsForName:@"channel"];
  for (GDataXMLElement *channel in channels) {            

    NSArray *items = [channel elementsForName:@"item"];
    for (GDataXMLElement *item in items) {

        GDataXMLElement *articleDesc = [item elementForChild:@"description"];
        NSArray *imgs = [articleDesc nodesForXPath:@"//img[@src]" error:nil];

        NSString *articleTitle = [item valueForChild:@"title"];
        NSString *url = [item valueForChild:@"link"];            
        NSString *articleDateString = [item valueForChild:@"pubDate"];

        Article *entry = [[[Article alloc] initWithTitle:articleTitle 
                                                     url:url 
                                                    date:articleDate] autorelease];
        [entries addObject:entry];
    }      
}

当我打印来控制articleDesc，的描述时，我会得到以下内容：

GDataXMLElement 0x70503b0: {type:1 name:description xml:"<description>&lt;span class="image-rss"&gt;&lt;a href="http://www.mysite.com/?p=672"&gt;&lt;img title="BlackBerry EMEA servers crash" src="http://www.mysite.com/wp-content/uploads/2011/10/blackberry-thumb-medium-300x187.jpg" alt="BlackBerry EMEA servers crash" width="200" height="124" /&gt;&lt;/a&gt;&lt;/span&gt;&lt;br/&gt;RIM has confirmed that…</description>"}

是否可以使用“快速”的src 属性解析它，或者我必须使用正则表达式来解析它？

所有的建议都非常欢迎。

Answer 1

我遇到了同样的问题并找到了解决办法。应该是这样的：

NSArray *imgs = [articleDesc nodesForXPath:@"//img/@src" error:nil];