Question

I’ve seen a few examples of RSS Feeds in ASP.NET MVC, like this, and some samples in projects (like Oxite), but none of them are complete.

Eg. None of them check for the header

  If-Modified-Since 

in the request, to save bandwidth.

I do not want to reinvent the wheel, so I stop here asking for some directions.

Answer 1

I ended up with this. Please comment or edit the post if you find any error or better way to do it.

RssController

Imports System.ServiceModel.Syndication Imports System.Xml Imports System.Web.HttpContext  Function MasterRSS()     Dim baseURL As String = 'http://www.mysite.com'     Dim feed As New SyndicationFeed('MySite - Master RSS', '', New Uri(baseURL))     ''//Add a custom attribute.     Dim xqName As New XmlQualifiedName('CustomAttribute')     feed.AttributeExtensions.Add(xqName, 'Value')      Dim sp As New SyndicationPerson('[e-mail]', 'Jerry Seinfeld', 'http://Jerry.blog.com')     feed.Authors.Add(sp)      Dim category As New SyndicationCategory('Category')     feed.Categories.Add(category)      feed.Contributors.Add(New SyndicationPerson('[e-mail]', 'Cosmo Kramer', 'http://kramer.blog.com'))     feed.Copyright = New TextSyndicationContent('MySite 2008')     feed.Description = New TextSyndicationContent('My description')      ''//Add a custom element.     Dim doc As New XmlDocument()     Dim feedElement As XmlElement = doc.CreateElement('CustomElement')     feedElement.InnerText = 'Some text'     feed.ElementExtensions.Add(feedElement)      feed.Generator = 'Custom'     feed.Id = 'MySiteFeedID'     feed.ImageUrl = New Uri('http://www.mysite.com/content/images/logo.png')      ''//Items     Dim ModifiedSince As Date     If Not Date.TryParse(Current.Request.Headers('If-Modified-Since'), ModifiedSince) Then         ModifiedSince = Date.Today.AddDays(-30) ''//Or whatever make sense to you.              Else         ModifiedSince.AddMinutes(-5) ''//Just in case, we do not want to miss any item.      End If      ''//the list of items.     Dim items As New List(Of SyndicationItem)()       Dim db As New mainDataContext     Dim textContent As TextSyndicationContent, Item As SyndicationItem      ''//Then send the list of post, comments, whatever.     Dim Posts = (From p In db.Posts Where c.Date >= ModifiedSince Order By p.Date Descending)     For Each Post In Posts         Dim sb As New StringBuilder         sb.AppendFormat('<p>{0}</p>', Post.FullText)         textContent = New TextSyndicationContent(sb.ToString, TextSyndicationContentKind.Html)         Item = New SyndicationItem('Post ' + Post.PostID.ToString, textContent, New Uri(baseURL + '/Post/View/' + Post.PostID.ToString), 'Post' + Post.PostID.ToString, Post.Date)         items.Add(Item)     Next       If items.Count = 0 Then         ''//send a 304 to the browser.         Return View('304')     End If      feed.Items = items     feed.Language = 'es-ar'     feed.LastUpdatedTime = (From i In items Select i.LastUpdatedTime Order By LastUpdatedTime Descending).FirstOrDefault      ''//Not needed in this sample.     ''//Dim link As New SyndicationLink(New Uri('http://server/link'), 'alternate', 'Link Title', 'text/html', 1000)     ''//feed.Links.Add(link)      ViewData('feed') = feed     Return View('Rss')  End Function 

Rss View (rss.aspx)

Dim htmlwriter As System.IO.Stream = Response.OutputStream Dim rssWriter As System.Xml.XmlWriter = System.Xml.XmlWriter.Create(htmlwriter) Dim feed As System.ServiceModel.Syndication.SyndicationFeed = ViewData('feed') Dim rssFormatter As New System.ServiceModel.Syndication.Rss20FeedFormatter(feed) rssFormatter.WriteTo(rssWriter) rssWriter.Close() 

This way, you can reuse the view