Blaze.Controllers.MessageProcessor.TransformAndExtractUrls C# (CSharp) Method

        public static string TransformAndExtractUrls(string message, out HashSet<string> extractedUrls)
        {
            const string urlPattern = @"((https?|ftp)://|www\.)[\w]+(.[\w]+)([\w\-\.\[\],@?^=%&amp;:/~\+#!]*[\w\-\@?^=%&amp;/~\+#\[\]])";

            var urls = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
            message = Regex.Replace(message, urlPattern, m =>
                                                             {
                                                                 string httpPortion = String.Empty;
                                                                 if (!m.Value.Contains("://"))
                                                                 {
                                                                     httpPortion = "http://";
                                                                 }

                                                                 string url = httpPortion + m.Value;

                                                                 urls.Add(HttpUtility.HtmlDecode(url));

                                                                 return String.Format(CultureInfo.InvariantCulture,
                                                                                      "<a rel=\"nofollow external\" target=\"_blank\" href=\"{0}\" title=\"{1}\">{1}</a>",
                                                                                      url, m.Value);
                                                             });

            extractedUrls = urls;
            return message;
        }