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String Strip Tags

References :

• http://weblogs.asp.net/rosherove/archive/2003/05/13/6963.aspx

Usage

• Example
  • I use StripTags in my RichTextBox WebControl to get the text value (eg. counting characters) of the whole html input.
• Example Code

  • string myHtml = "<table><tr><td>my table</td></tr></table>";
    string myText = Utils.String.StripTags(myHtml);
    

The StripTags function :

public static string StripTags(string pTaggedText)
{
	return StripTags(pTaggedText, new string[] { });
}
public static string StripTags(string pTaggedText, string[] pTagsToStrip)
{
	if (pTagsToStrip.Length == 0) //strip all tags
	{
		Regex rx = new Regex("<[^>]+>");
		string resultText = rx.Replace(pTaggedText, "");
 
		return resultText;
	}
	else //strip only specified tags
	{
		string tagsToStrip = "";
		for (int s = 0; s < pTagsToStrip.Length; s++)
		{
			if (s > 0) { tagsToStrip += "|"; }
			tagsToStrip += pTagsToStrip[s];
		}
		Regex rx = new Regex("</?(?i:" + tagsToStrip + ")([^>]*>");
		string resultText = rx.Replace(pTaggedText, "");
 
		return resultText;
	}
}

I have not worked enough on the above function, that I am confident it is reliable. I would very much appreciate comments on how to improve the function. One way to improve the function is to improve the regular expression used, currently I have these in mind :

• <[^>]+> : the one I am using because the non-gready match is logically builtin.
• <(.|\n)*?> : secures that tags spanning multiple lines are matched (also secures non-gready matching using "*?").
• </?(?i:script|embed|iframe)([^>])*> : the principle I am using for removing selected tags.

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