Reading non-standard elements in a SyndicationItem with SyndicationFeed

Question

With .net 3.5, there is a SyndicationFeed that will load in a RSS feed and allow you to run LINQ on it.

Here is an example of the RSS that I am loading:

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Answer 1

You can use a combination of LINQ and XPathNavigator to extract the syndication extensions of a feed item (based on namespace URI of the extension). For item enclosures, you will want to examine the item links collection for links that have a RelationshipType of enclosure.

Example:

HttpWebRequest webRequest   = WebRequest.Create("http://www.pwop.com/feed.aspx?show=dotnetrocks&filetype=master") as HttpWebRequest;

using (Stream stream = webRequest.GetResponse().GetResponseStream())
{
    XmlReaderSettings settings  = new XmlReaderSettings();
    settings.IgnoreComments     = true;
    settings.IgnoreWhitespace   = true;

    using(XmlReader reader = XmlReader.Create(stream, settings))
    {
        SyndicationFeed feed    = SyndicationFeed.Load(reader);

        foreach(SyndicationItem item in feed.Items)
        {
            // Get values of syndication extension elements for a given namespace
            string extensionNamespaceUri            = "http://www.itunes.com/dtds/podcast-1.0.dtd";
            SyndicationElementExtension extension   = item.ElementExtensions.Where(x => x.OuterNamespace == extensionNamespaceUri).FirstOrDefault();
            XPathNavigator dataNavigator            = new XPathDocument(extension.GetReader()).CreateNavigator();

            XmlNamespaceManager resolver    = new XmlNamespaceManager(dataNavigator.NameTable);
            resolver.AddNamespace("itunes", extensionNamespaceUri);

            XPathNavigator authorNavigator      = dataNavigator.SelectSingleNode("itunes:author", resolver);
            XPathNavigator subtitleNavigator    = dataNavigator.SelectSingleNode("itunes:subtitle", resolver);
            XPathNavigator summaryNavigator     = dataNavigator.SelectSingleNode("itunes:summary", resolver);
            XPathNavigator durationNavigator    = dataNavigator.SelectSingleNode("itunes:duration", resolver);

            string author   = authorNavigator != null ? authorNavigator.Value : String.Empty;
            string subtitle = subtitleNavigator != null ? subtitleNavigator.Value : String.Empty;
            string summary  = summaryNavigator != null ? summaryNavigator.Value : String.Empty;
            string duration = durationNavigator != null ? durationNavigator.Value : String.Empty;

            // Get attributes of  element
            foreach (SyndicationLink enclosure in item.Links.Where(x => x.RelationshipType == "enclosure"))
            {
                Uri url             = enclosure.Uri;
                long length         = enclosure.Length;
                string mediaType    = enclosure.MediaType;
            }
        }
    }
}