Question

I have a large string and it might have the following:

<div id="Specs" class="plinks">
<div id="Specs" class="plinks2">
<div id="Specs" class="sdfsf">
<div id="Specs" class="ANY-OTHER_NAME">

How can I replace values in the string from anything above to:

<div id="Specs" class="">

this is what I came up with, but it does not work:

        string source = "bunch of text";
        string regex = "<div id=\"Specs\" class=[\"']([^\"']*)[\"']>";
        string regexReplaceTo = "<div id=\"Specs\" class=\"\">";
        string output = Regex.Replace(source, regex, regexReplaceTo); 

Answer 1

If your input isn’t XML compliant, which most HTML isn’t, then you can use the HTML Agility Pack to parse the HTML and manipulate the contents. With the HTML Agility PAck, combined with Linq or Xpath, the order of your attributes no longer matters (which it does when you use Regex) and the overall stability of your solution increases a lot.

Using the HTML Agility Pack (project page, nuget), this does the trick:

HtmlDocument doc = new HtmlDocument();
doc.LoadHtml("your html here"); 
// or doc.Load(stream);

var nodes = doc.DocumentNode.DescendantNodes("div").Where(div => div.Id == "Specs");

foreach (var node in nodes)
{
    var classAttribute = node.Attributes["class"];
    if (classAttribute != null)
    {
        classAttribute.Value = string.Empty;
    }
}

var fixedText = doc.DocumentNode.OuterHtml;
//doc.Save(/* stream */);