How to add CSS link in .NET SyndicationFeed?

Question

I created a simple SyndicationFeed with many SyndicationItems. Each SyndicationItem has an HtmlContent. HtmlContent is a table. This displays OK, but now I need the minimum number of styles / additions on the table. I believe that I need to add a link to the stylesheet, for example

<?xml-stylesheet type="text/css" href="http://you.com/rss.css" ?> 

But I don’t see how to do this with the .NET 4.5 classes SyndicationFeed or Atom10FeedFormatter.

Here is the code (pseudo) that is generated by the WCF service.

 var feed = new feed(......); var xqn = new XmlQualifiedName( "mysys" , "http://www.w3.org/2000/xmlns/" ); feed.AttributeExtensions.Add( xqn , myuri ); feed.ElementExtensions.Add( "creator" , "sys" , teaminfo ); feed.Authors.Add( new SyndicationPerson( emailaddr) ); feed.Categories.Add( new SyndicationCategory( mycategory ) ); feed.Description = new TextSyndicationContent( feedDesc ); feed.Copyright = SyndicationContent.CreatePlaintextContent(copyr); feed.Language = "en-us"; feed.ImageUrl = new Uri( myuri + "/logo" ); var dbitems = GetListFromDb(key); var syndItems = new List<synitem>(); foreach (var item in dbitems) { var htmlContent = SyndicationContent.CreateHtmlContent( MakeHtmlFromStuff(item) ); var itemUri = new Uri( myuri + itemuri ); var synitem = new synitem( item.code , htmlContent , itemUri , item.key , DateTimeOffset.UtcNow ); syndItems.Add( synitem); } feed.Items = syndItems; return new Atom10FeedFormatter(feed); 

Hope missing something obvious. All ideas were appreciated.

Thanks.

Answer 1

I think I need to add a link to the stylesheet, for example

 <?xml-stylesheet type="text/css" href="http://you.com/rss.css" ?> 

But I do not see how to do this with .NET 4.5 SyndicationFeed or Atom10FeedFormatter Class.

Here is an example of complete code on how to do this:

 using System; using System.Collections.Generic; using System.ServiceModel.Syndication; using System.Xml; namespace FeedProcessing { class FeedProcessing { static void Main(string[] args) { FeedProcessing fp = new FeedProcessing(); fp.CreateFeed(); } public void CreateFeed() { SyndicationFeed feed = new SyndicationFeed("Feed Title", "Feed Description", new Uri("http://Feed/Alternate/Link"), "FeedID", DateTime.Now); // Add a custom attribute. XmlQualifiedName xqName = new XmlQualifiedName("CustomAttribute"); feed.AttributeExtensions.Add(xqName, "Value"); SyndicationPerson sp = new SyndicationPerson(" [e-mail] ", "Jesper Aaberg", "http://Jesper/Aaberg"); feed.Authors.Add(sp); SyndicationCategory category = new SyndicationCategory("FeedCategory", "CategoryScheme", "CategoryLabel"); feed.Categories.Add(category); feed.Contributors.Add(new SyndicationPerson(" [e-mail] ", "Lene Aaling", "http://lene/aaling")); feed.Copyright = new TextSyndicationContent("Copyright 2007"); feed.Description = new TextSyndicationContent("This is a sample feed"); // Add a custom element. XmlDocument doc = new XmlDocument(); XmlElement feedElement = doc.CreateElement("CustomElement"); feedElement.InnerText = "Some text"; feed.ElementExtensions.Add(feedElement); feed.Generator = "Sample Code"; feed.Id = "FeedID"; feed.ImageUrl = new Uri("http://server/image.jpg"); TextSyndicationContent textContent = new TextSyndicationContent("Some text content"); SyndicationItem item = new SyndicationItem("Item Title", textContent, new Uri("http://server/items"), "ItemID", DateTime.Now); List<SyndicationItem> items = new List<SyndicationItem>(); items.Add(item); feed.Items = items; feed.Language = "en-us"; feed.LastUpdatedTime = DateTime.Now; SyndicationLink link = new SyndicationLink(new Uri("http://server/link"), "alternate", "Link Title", "text/html", 1000); feed.Links.Add(link); XmlWriter atomWriter = XmlWriter.Create("atom.xml"); atomWriter.WriteProcessingInstruction("xml-stylesheet", "type='text/css' href='http://you.com/rss.css'"); Atom10FeedFormatter atomFormatter = new Atom10FeedFormatter(feed); atomFormatter.WriteTo(atomWriter); atomWriter.Close(); XmlWriter rssWriter = XmlWriter.Create("rss.xml"); rssWriter.WriteProcessingInstruction("xml-stylesheet", "type='text/css' href='http://you.com/rss.css'"); Rss20FeedFormatter rssFormatter = new Rss20FeedFormatter(feed); rssFormatter.WriteTo(rssWriter); rssWriter.Close(); } } } 

When this program is executed, two files are created :

atom.xml:

 <?xml version="1.0" encoding="utf-8"?> <?xml-stylesheet type='text/css' href='http://you.com/rss.css'?> <feed xml:lang="en-us" CustomAttribute="Value" xmlns="http://www.w3.org/2005/Atom"> <title type="text">Feed Title</title> <subtitle type="text">This is a sample feed</subtitle> <id>FeedID</id> <rights type="text">Copyright 2007</rights> <updated>2012-12-28T19:50:18-08:00</updated> <category term="FeedCategory" label="CategoryLabel" scheme="CategoryScheme" /> <logo>http://server/image.jpg</logo> <author> <name>Jesper Aaberg</name> <uri>http://Jesper/Aaberg</uri> <email> [e-mail] </email> </author> <contributor> <name>Lene Aaling</name> <uri>http://lene/aaling</uri> <email> [e-mail] </email> </contributor> <generator>Sample Code</generator> <link rel="alternate" href="http://feed/Alternate/Link" /> <link rel="alternate" type="text/html" title="Link Title" length="1000" href="http://server/link" /> <CustomElement xmlns="">Some text</CustomElement> <entry> <id>ItemID</id> <title type="text">Item Title</title> <updated>2012-12-28T19:50:18-08:00</updated> <link rel="alternate" href="http://server/items" /> <content type="text">Some text content</content> </entry> </feed> 

and rss.xml:

 <?xml version="1.0" encoding="utf-8"?> <?xml-stylesheet type='text/css' href='http://you.com/rss.css'?> <rss xmlns:a10="http://www.w3.org/2005/Atom" version="2.0"> <channel CustomAttribute="Value"> <title>Feed Title</title> <link>http://feed/Alternate/Link</link> <description>This is a sample feed</description> <language>en-us</language> <copyright>Copyright 2007</copyright> <managingEditor> [e-mail] </managingEditor> <lastBuildDate>Fri, 28 Dec 2012 19:50:18 -0800</lastBuildDate> <category domain="CategoryScheme">FeedCategory</category> <generator>Sample Code</generator> <a10:contributor> <a10:name>Lene Aaling</a10:name> <a10:uri>http://lene/aaling</a10:uri> <a10:email> [e-mail] </a10:email> </a10:contributor> <image> <url>http://server/image.jpg</url> <title>Feed Title</title> <link>http://feed/Alternate/Link</link> </image> <a10:id>FeedID</a10:id> <a10:link rel="alternate" type="text/html" title="Link Title" length="1000" href="http://server/link" /> <CustomElement>Some text</CustomElement> <item> <guid isPermaLink="false">ItemID</guid> <link>http://server/items</link> <title>Item Title</title> <description>Some text content</description> <a10:updated>2012-12-28T19:50:18-08:00</a10:updated> </item> </channel> </rss> 

Explanation

Whenever an XmlWriter is created, but before the call:

 atomFormatter.WriteTo(atomWriter); 

or

 rssFormatter.WriteTo(rssWriter); 

call the WriteProcessingInstruction() method on the corresponding XmlWriter instance, passing it two required parameters - the PI name (in this case, "xml-stylesheet" ) and PI text (in this case, "type='text/css' href='http://you.com/rss.css'" ).