Question

trying to use regex to replace any white space with “ ”, inside of example html

<span someattr="a">and some words with spaces</span>

It’s a desktop app and this html is coming to/from a third party control and don’t have the luxury of working with any type of html parsing so am stuck with regex

I can’t seem come up with a regex that would just match any whitespace inside any number of span tags.

Thanks

Answer 1

This could potentially be very slow with very large strings.

But this works:

(?<=\<span[^>]*>[^<]+)\s(?=[^<]+\</span>)

With a replacement string of:

 

The reason I say it might be slow is that it’s having to find the whitespace (\s) and then search towards the left and to the right to see if it’s surrounded by a span tag. And it’ll have to do the same thing for every character of whitespace individually. But I believe this should work reliably as long as your HTML is well-formed and you aren’t dealing with nested span tags.

And by the way, since this is for .NET you can use Regex Hero to build the code for you:

string strRegex = "(?<=\<span[^>]*>[^<]+)\s(?=[^<]+\</span>)";
RegexOptions myRegexOptions = RegexOptions.None;
Regex myRegex = new Regex(strRegex, myRegexOptions);
string strTargetString = "<span someattr=\"a\">and some words with spaces</span>";
string strReplace = "&nbsp;";

return myRegex.Replace(strTargetString, strReplace);