How to remove blank lines from HTML with HTMLAgilityPack?

c# html html-agility-pack

Question

I have a HTML document that contains lots of needless blank lines which I'd like to remove. Here's a sample of the HTML:

<html>

<head>


</head>

<body>

<h1>Heading</h1>

<p>Testing

I've tried the following code but it removed every newline, I just want to remove the ones that are blank lines.

static string RemoveLineReturns(string html)
    {
        html = html.Replace(Environment.NewLine, "");
        return html;
    }

Any idea how to do this with HTMLAgilityPack? Thanks, J.

Accepted Answer

I don't think that HTMLAgilityPack currently features a native solution for that.

For such scenarios I use the following Regex:

html = Regex.Replace(html, @"( |\t|\r?\n)\1+", "$1");

This preserves whitespaces and line endings correctly, while condensing multiple tabs, newlines and whitespaces into one.


Popular Answer

One possible way using Html Agility Pack :

var doc = new HtmlDocument();
//TODO: load your HtmlDocument here

//select all empty (containing white-space(s) only) text nodes :
var xpath = "//text()[not(normalize-space())]";
var emptyNodes = doc.DocumentNode.SelectNodes(xpath);

//replace each and all empty text nodes with single new-line text node
foreach (HtmlNode emptyNode in emptyNodes)
{
    emptyNode.ParentNode
             .ReplaceChild(HtmlTextNode.CreateNode(Environment.NewLine) 
                            , emptyNode
                           );
}


Licensed under: CC-BY-SA with attribution
Not affiliated with Stack Overflow
Is this KB legal? Yes, learn why
Licensed under: CC-BY-SA with attribution
Not affiliated with Stack Overflow
Is this KB legal? Yes, learn why