htmlagilitypack invalid cast exception when grabbing nodes with certain classes - exception

Question

I'm wanting to grab div items from an HTML page that contains certain class types.
I'm using this:
HtmlNode authorNode =(HtmlNode) doc.DocumentNode.Descendants("div").Where(d => d.Attributes.Contains("class") && d.Attributes["class"].Value.Split(' ').Any(b => b.Equals("byline") && b.Equals("list-pipes")));
and I get this exception
System.InvalidCastException was unhandled
HResult=-2147467262
Message=Unable to cast object of type 'WhereEnumerableIterator`1[HtmlAgilityPack.HtmlNode]' to type 'HtmlAgilityPack.HtmlNode'.
Source=Project1
StackTrace:
at Project1.Scraper.processBI_Article(String uri) in C:\Users\jgarber\Documents\Visual Studio 2010\Projects\Project1\Project1\Scraper.cs:line 233
at Project1.Scraper.processNode(String uri, HtmlNode parentNode) in C:\Users\jgarber\Documents\Visual Studio 2010\Projects\Project1\Project1\Scraper.cs:line 194
at Project1.Scraper.ExecuteScraping() in C:\Users\jgarber\Documents\Visual Studio 2010\Projects\Project1\Project1\Scraper.cs:line 107
at Project1.WebscrapingMain.Main() in C:\Users\jgarber\Documents\Visual Studio 2010\Projects\Project1\Project1\WebscrapingMain.cs:line 64
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException:
I'm confused as to what I need to do now in order to get this to work. Any help would be greatly appreciated.

Answer 1

The code returns an Enumerable of HtmlNode, not just one node (you're using .Where, which returns a all items matching). If you're only interested in the first item, use First or FirstOrDefault or if you know there to be only one item, use Single or SingleOrDefault instead of just Where.
So:
HtmlNode authorNode = doc.DocumentNode.Descendants("div")
.Where(d => d.Attributes.Contains("class")
&& d.Attributes["class"].Value.Split(' ')
.Any(b => b.Equals("byline") && b.Equals("list-pipes")))
.FirstOrDefault();
Or assign it to a Enumerable of HtmlNode:
IEnumerable<HtmlNode> authorNodes = doc.DocumentNode.Descendants("div")
.Where(d => d.Attributes.Contains("class")
&& d.Attributes["class"].Value.Split(' ')
.Any(b => b.Equals("byline") && b.Equals("list-pipes")));