Question

I’m creating a post system, where I will tag external images, Flash, SL etc. with [image:http://anything/anyimage.jpg%5D or [silverlight:http://anothersite/ilovesilverlight.xap%5D etc. I’ll be rendering the object tags for HTML upon finding the links. I’m stuck with regex, I am quite new to regex so please be constructive while replying, what is wrong with this:

        if (text.Contains("[flash:"))
        {
            rgx = new Regex(@"\[flash:(.^\])\]");
            text = rgx.Replace(text, (m =>
            {
                string val = m.Groups[1].Value;
                FlashRenderer ir = new FlashRenderer(val);
                return ir.Render();
            }));
        }

Forget about the FlashRenderer and what it returns, my problem is with matching.
I get into the if block, but cannot find any instances that match the regex, although I have. I can have multiple external objects in one post, so what I’m trying to do is to negate the ] character in the match. If I don’t negate ], there is no problem if I have only one object and no other ] characters anywhere, but if I have more ]‘s then everything gets messed up as the first regex matches the last occurance of ] on the whole post, and returning the rest of the whole post as the supposed “URL”.

Answer 1

Try this:

new Regex(@"\[flash:([^\]]+)\]");

\[flash:          # prefix
  (               # capture group
      [^\]]+      # one or more characters except ]
  )               #
\]                # suffix