Checking a HTML string for unopened tags

Question

I have a string as a HTML source and I want to check whether the HTML source which is string contains a tag which is not opened.

For example the string below contains </u> after WAVEFORM which has no opening <u>.

WAVEFORM</u> YES, <u>NEGATIVE AUSCULTATION OF EPIGASTRUM</u> YES,

I just want to check for these types of unopened tag and then I have to append the open tag to the start of the string?

Answer 1

For this specific case you can use HTML Agility Pack to assert if the HTML is well formed or if you have tags not opened.

var htmlDoc = new HtmlDocument();

htmlDoc.LoadHtml(
    "WAVEFORM</u> YES, <u>NEGATIVE AUSCULTATION OF EPIGASTRUM</u> YES,");

foreach (var error in htmlDoc.ParseErrors)
{
    // Prints: TagNotOpened
    Console.WriteLine(error.Code);
    // Prints: Start tag <u> was not found
    Console.WriteLine(error.Reason); 
}