Umbraco V5 Example - News feed from News List (atom and rss)

NewsFeed.cshtml

@*
================= Credit goes to Jorge Lusar for creating this =================
Original's at: https://gist.github.com/jorgelusar


Parameters
  FeedItems (int, optional, default 20, number of items to be displayed)
  FeedTitle (string, optional, default domain name, the title of the feed)
  FeedDescription (string, optional, default domain name, the description of the feed)
  Author (string, optional, default 'admin', the author name or website name to ensure the atom feed is valid)
  IsAtom (bool, optional, default false, will display an atom feed if true; otherwise, a rss feed)
*@


@inherits PartialViewMacroPage
@using System.ServiceModel.Syndication
@using System.Text
@using System.Xml
@using Umbraco.Cms.Web.Macros
@using System.Linq

@{
    var root = DynamicModel;

    // Get the base url to contruct the links for the feeds
    var baseUrl = new UriBuilder(Context.Request.Url.Scheme, Context.Request.Url.Host).Uri;

    // Get the parameters passed by the macro
    int feedItems = string.IsNullOrWhiteSpace(Model.MacroParameters.FeedItems) ? 20 : int.Parse(Model.MacroParameters.FeedItems);
    string feedTitle = string.IsNullOrWhiteSpace(Model.MacroParameters.FeedTitle) ? baseUrl.ToString() : Model.MacroParameters.FeedTitle;
    string feedDescription = string.IsNullOrWhiteSpace(Model.MacroParameters.FeedDescription) ? baseUrl.ToString() : Model.MacroParameters.FeedDescription;
    string author = string.IsNullOrWhiteSpace(Model.MacroParameters.Author) ? "admin" : Model.MacroParameters.Author;
    bool isAtom;
    bool.TryParse(Model.MacroParameters.IsAtom, out isAtom);

    // Sort the items by CreateDate and limit the number of feeds based on the feedItems parameter
    // Notice that you could sort by "UpdateDate" too
    IList<dynamic> news = root.Children.OrderBy("CreateDate");

    // Let's create a list of Syndication Items
    var items = new List<SyndicationItem>();

    foreach (var item in news.Take(feedItems))
    {
      // Get the title of the item. 
      string title = item.Name;

      // Get the content from the body text and decode it
      string content = item.BodyText;

      // Create the link based on the baseUrl and the item url
      Uri itemAlternateLink = new Uri(baseUrl, item.Url);

      // Get the updateDate
      DateTime updatedTime = DateTime.Parse(item.UpdateDate.ToString());

      // Add the SyndicationItem to the list
      SyndicationItem syndicationItem = new SyndicationItem
      {
        Id = itemAlternateLink.AbsoluteUri,
        Title = SyndicationContent.CreatePlaintextContent(title),
        Content = SyndicationContent.CreateHtmlContent(content)
      };

      // Set the PublishDate or LastUpdatedTime based on the information whether
      // the feed will be a rss or a atom
      if (isAtom)
      {
        syndicationItem.LastUpdatedTime = updatedTime;
      }
      else
      {
        syndicationItem.PublishDate = updatedTime;
      }

      // Add the itemAlternateLink
      syndicationItem.Links.Add(SyndicationLink.CreateAlternateLink(itemAlternateLink));

      // Add the item
      items.Add(syndicationItem);
    }

    // Get the feed link
    var feedLink = new Uri(baseUrl, Context.Request.RawUrl);

    // Get the UpdateDate for the first item on the list
    var feedDate = DateTime.Parse(news.First().UpdateDate.ToString());

    // Create the feed
    var feed = new SyndicationFeed(feedTitle, feedDescription, feedLink, feedLink.AbsoluteUri, feedDate, items);

    // Improved interoperability with feed readers by implementing atom:link with rel="self"
    feed.Links.Add(SyndicationLink.CreateSelfLink(feedLink));

    // Let's save the content to a MemoryStream. You could use StringWriter too but you will have to deal with UTF-16 encoding
    using (var ms = new MemoryStream())
    {
      // Ensure the writer is UTF8 and nicely indented
      using (var writer = new XmlTextWriter(ms, Encoding.UTF8) { Formatting = Formatting.Indented })
      {
        // Write <?xml version="1.0" encoding="utf-8"?>
        writer.WriteStartDocument();

        // Save as atom or as rss
        if (isAtom)
        {
          // This feed won't validate unless you add an author and name
          feed.Authors.Add(new SyndicationPerson { Name = author });
          feed.SaveAsAtom10(writer);
        }
        else
        {
          feed.SaveAsRss20(writer);
        }
      }

      var sb = new StringBuilder(Encoding.UTF8.GetString(ms.ToArray()));

      if (!isAtom)
      {
        // Although this feed is valid, interoperability with feed readers could be improved by avoiding Namespace Prefix: a10
        sb.Replace("xmlns:a10", "xmlns:atom").Replace("a10:", "atom:");
      }

      // Ensure the content type is correct
      Context.Response.ContentType = isAtom ? "application/atom+xml" : "application/rss+xml";

      // Write the content
      Context.Response.Write(sb.ToString());
    }
}