Web Development

private string Format2Html(string Formatted)
{
	string[] hdrTags = {"h1", "h2", "h3", "h4", "h5"};

	string[] nmlTags = { "b", "i", "u", "center" };

	string[][] splTags = { new string[] { "link", "a", "href=\"%\"" },
				new string[] { "mail", "a", "href=\"mailto:%\"" },
				new string[] { "font", "font", "face=\"%\"", "color=\"%\"", "size=\"%\"" } };

	string rtn = Formatted.Replace("&", "&").
		Replace("<", "<").
		Replace(">", ">").
		Replace("£", "£").
		Replace("\"", """).
		Replace(Environment.NewLine, "<br>" + Environment.NewLine);

	int next = 0, start = 0;

	for (start=rtn.IndexOf('['); start > -1; start=rtn.IndexOf('[', start + 1))
	{
		string replacement = "";
		next = rtn.IndexOf('[', start + 1);
		int end = rtn.IndexOf(']', start + 1);

		if (end == -1) end = rtn.Length - 1;
		if (end > next && next > -1) end = next;

		int length = (end - start) + 1;
		string tag = rtn.Substring(start, length).TrimEnd(']').TrimStart('[').Trim(' ');

		string[] tkn = tag.Split(' ', ',');
		
		for (int i = 0; i < hdrTags.Length; i++)
		{
			if (hdrTags[i] == tkn[0])
			{
				replacement = "<" + hdrTags[i] + ">";
			}
			else if (hdrTags[i] == tkn[0].TrimStart('/'))
			{
				replacement = "</" + hdrTags[i] + ">";
				if (rtn.Substring(end + 1, 4) == "<br>") end += 4;
			}
		}

		for (int i = 0; i < nmlTags.Length; i++)
		{
			if (nmlTags[i] == tkn[0])
			{
				replacement = "<" + nmlTags[i] + ">";
			}
			else if (nmlTags[i] == tkn[0].TrimStart('/'))
			{
				replacement = "</" + nmlTags[i] + ">";
			}
		}

		for (int i = 0; i < splTags.Length; i++)
		{
			if (splTags[i][0] == tkn[0])
			{
				replacement = "<" + splTags[i][1];
				for (int j = 1, k = 2; (j < tkn.Length) && (k < splTags[i].Length); j++, k++)
				{
					while (tkn[j].Length == 0) j++;
					replacement += " " + splTags[i][k].Replace("%", tkn[j]);
				}
				replacement += ">";
			}
			else if (splTags[i][0] == tkn[0].TrimStart('/'))
			{
				replacement = "</" + splTags[i][1] + ">";
			}
		}

		if (replacement.Length > 0)
			rtn = rtn.Remove(start, (end - start) + 1).Insert(start, replacement);
	}

	return rtn;
}

...

using System.Text.RegularExpressions;
...
static bool IsLikeRe(string src, string pattern) 
{
    return Regex.IsMatch(src, pattern, 
        RegexOptions.IgnoreCase | RegexOptions.Singleline);
}
 
static string ReReplace(string src, string pattern, string replace) 
{
    return Regex.Replace(src, pattern, replace,
        RegexOptions.IgnoreCase | RegexOptions.Singleline);
}
 
static string ReReplaceAll(string src, string pattern, string replace)
{
    string ret = src;
    while (IsLikeRe(ret, pattern))
        ret = ReReplace(ret, pattern, replace);
 
    return ret;
}
 
static string StripScript(string html)
{
    // Strip <script...> tags
    string res = ReReplaceAll(html, "<script(.*)>", "&lt;script$1&gt;");
    // Strip </script...> tags
    res = ReReplaceAll(res, "</script(.*?)>", "&lt;/script$1&gt;");
 
    // Strip object tags
    res = ReReplaceAll(res, "<(object|applet|embed|param)([^>]*)>", 
        "&lt;$1$2&gt;");
    res = ReReplaceAll(res, "</(object|applet|embed|param)([^>]*)>", 
        "&lt;$1$2&gt;");
 
    // Strip event handlers from tags
    res = ReReplaceAll(res,
        @"<([^>]+?)\son(?:[^>]+?)=(['""])(?:[^>]+?)\2([^>]*?)>",
        "<$1$3>");
 
    return res;
}