RSS.cs

public Task GenerateRssFeedAsync(SiteContext siteContext, IEnumerable<StructuredDataItem> items, string outputFilePath)
        {
            var feed = new RssFeed
            {
                Channel =
                {
                    Link = new Uri(Flurl.Url.Combine(siteContext.SiteTemplateMetaData.Url, "feed", "rss.xml")),
                    Title = siteContext.SiteTemplateMetaData.Title,
                    Description = siteContext.SiteTemplateMetaData.Description,
                    LastBuildDate = DateTime.Now,
                    Language = CultureInfo.CurrentCulture,
                    Copyright = $"Endjin Limited {DateTime.Now.Year}"
                }
            };

            foreach(var item in items.OrderByDescending(x => x.Date))
            {
                var rssItem = new RssItem
                {
                    Author = item.Author.DisplayName,
                    Description = item.Excerpt,
                    Guid = new RssGuid(Flurl.Url.Combine(siteContext.SiteTemplateMetaData.Url, item.Url), true),
                    Link = new Uri(Flurl.Url.Combine(siteContext.SiteTemplateMetaData.Url, item.Url)),
                    PublicationDate = item.Date,
                    Title = item.Title,
                };

                var contentExtension = new SiteSummaryContentSyndicationExtension();
                contentExtension.Context.Encoded = item.Content;
                rssItem.AddExtension(contentExtension);

                feed.Channel.AddItem(rssItem);
            }

            feed.Channel.Items = feed.Channel.Items.Take(50);

            using (FileStream filestream = new FileStream(Path.Combine(outputFilePath, "rss.xml"), FileMode.Create))
            {
                var settings = new SyndicationResourceSaveSettings { CharacterEncoding = Encoding.UTF8 };
                feed.Save(filestream, settings);
            }

            return Task.CompletedTask;
        }