Parsing HTML page with HtmlAgilityPack

Question

Using C# I would like to know how to get the Textbox value (i.e: john) from this sample html script :

<TD class=texte width="50%"> <DIV align=right>Name :<B> </B></DIV></TD> <TD width="50%"><INPUT class=box value=John maxLength=16 size=16 name=user_name> </TD> <TR vAlign=center> 

Answer 1

There are a number of ways to select elements using the agility pack.

Let's assume we have defined our HtmlDocument as follows:

string html = @"<TD class=texte width=""50%""> <DIV align=right>Name :<B> </B></DIV></TD> <TD width=""50%"">     <INPUT class=box value=John maxLength=16 size=16 name=user_name> </TD> <TR vAlign=center>";  HtmlDocument htmlDoc = new HtmlDocument(); htmlDoc.LoadHtml(html); 

1. Simple LINQ
We could use the Descendants() method, passing the name of an element we are in search of:

var inputs = htmlDoc.DocumentNode.Descendants("input");  foreach (var input in inputs) {     Console.WriteLine(input.Attributes["value"].Value);     // John } 

2. More advanced LINQ
We could narrow that down by using fancier LINQ:

var inputs = from input in htmlDoc.DocumentNode.Descendants("input")              where input.Attributes["class"].Value == "box"              select input;  foreach (var input in inputs) {     Console.WriteLine(input.Attributes["value"].Value);     // John } 

3. XPath
Or we could use XPath.

string name = htmlDoc.DocumentNode     .SelectSingleNode("//td/input")     .Attributes["value"].Value;  Console.WriteLine(name); //John 

Answer 2

HtmlDocument doc = new HtmlDocument(); doc.LoadHtml(html); XPathNavigator docNav = doc.CreateNavigator();  XPathNavigator node = docNav.SelectSingleNode("//td/input/@value");  if (node != null) {     Console.WriteLine("result: " + node.Value); } 

I wrote this pretty quickly, so you'll want to do some testing with more data.

NOTE: The XPath strings apparently have to be in lower-case.

EDIT: Apparently the beta now supports Linq to Objects directly, so there's probably no need for the converter.