HtmlAgilityPack HasAttribute?

mpen picture mpen · Nov 3, 2010 · Viewed 10k times · Source

All I want to do is

node.Attributes["class"].Value

But if the node doesn't have the class attribute, it crashes. So, I have to check for its existence first, right? How do I do that? Attributes is not a dict (its a list that contains an internal dict??), and there's no HasAttribute method (just a HasAttributes which indicates if it has any attribute at all). What do I do?

Answer

Ole Melhus picture Ole Melhus · Nov 3, 2010

Updated answer

Use node.Attributes["class"]?.Value to return null if the attribute is missing. This will be the same as the ValueOrDefault() below.

Original answer

Try this:

String val;
if(node.Attributes["class"] != null)
{
  val = node.Attributes["class"].Value;
}

Or you might be able to add this

public static class HtmlAgilityExtender
{
    public static String ValueOrDefault(this HtmlAttribute attr)
    {
        return (attr != null) ? attr.Value : String.Empty;
    }
}

And then use

node.Attributes["class"].ValueOrDefault();

I havent tested that one, but it should work.