Remove attributes using HtmlAgilityPack

Ted Nyberg picture Ted Nyberg · May 1, 2011 · Viewed 14.8k times · Source

I'm trying to create a code snippet to remove all style attributes regardless of tag using HtmlAgilityPack.

Here's my code:

var elements = htmlDoc.DocumentNode.SelectNodes("//*");

if (elements!=null)
{
    foreach (var element in elements)
    {
        element.Attributes.Remove("style");
    }
}

However, I'm not getting it to stick? If I look at the element object immediately after Remove("style"). I can see that the style attribute has been removed, but it still appears in the DocumentNode object. :/

I'm feeling a bit stupid, but it seems off to me? Anyone done this using HtmlAgilityPack? Thanks!

Update

I changed my code to the following, and it works properly:

public static void RemoveStyleAttributes(this HtmlDocument html)
{
   var elementsWithStyleAttribute = html.DocumentNode.SelectNodes("//@style");

   if (elementsWithStyleAttribute!=null)
   {
      foreach (var element in elementsWithStyleAttribute)
      {
         element.Attributes["style"].Remove();
      }
   }
}

Answer

Alex picture Alex · May 6, 2011

Your code snippet seems to be correct - it removes the attributes. The thing is, DocumentNode .InnerHtml(I assume you monitored this property) is a complex property, maybe it get updated after some unknown circumstances and you actually shouldn't use this property to get the document as a string. Instead of it HtmlDocument.Save method for this:

string result = null;
using (StringWriter writer = new StringWriter())
{
    htmlDoc.Save(writer);
    result = writer.ToString();
}

now result variable holds the string representation of your document.

One more thing: your code may be improved by changing your expression to "//*[@style]" which gets you only elements with style attribute.