ADBaseLibrary.TemplateParser.ValidateTemplate C# (CSharp) Method

        public static bool ValidateTemplate(string template, out string unknownvariable)
        {
            MatchCollection m = _varRegex.Matches(template);
            foreach (Match match in m)
            {
                if (match.Success)
                {
                    string t = match.Groups["variable"].Value.ToLower();
                    int idx = t.IndexOf(":",StringComparison.InvariantCulture);
                    if (idx > 0)
                        t = t.Substring(0, idx);
                    if (!Variables.Contains(t))
                    {
                        unknownvariable = t;
                        return false;
                    }
                }
            }
            unknownvariable = null;
            return true;
        }