C# Convert Relative to Absolute Links in HTML String

Question

I\'m mirroring some internal websites for backup purposes. As of right now I basically use this c# code:

System.Net.WebClient client = new System.Net.WebCli         


        

Answer 1

Uri WebsiteImAt = new Uri(
       "http://www.w3schools.com/media/media_mimeref.asp?q=1&s=2,2#a");
string href = new Uri(WebsiteImAt, "/something/somethingelse/filename.asp")
       .AbsoluteUri;
string href2 = new Uri(WebsiteImAt, "something.asp").AbsoluteUri;
string href3 = new Uri(WebsiteImAt, "something").AbsoluteUri;

which with your Regex-based approach is probably (untested) mappable to:

        String value = Regex.Replace(text, "<(.*?)(src|href)=\"(?!http)(.*?)\"(.*?)>", match => 
            "<" + match.Groups[1].Value + match.Groups[2].Value + "=\""
                + new Uri(WebsiteImAt, match.Groups[3].Value).AbsoluteUri + "\""
                + match.Groups[4].Value + ">",RegexOptions.IgnoreCase | RegexOptions.Multiline);

I should also advise not to use Regex here, but to apply the Uri trick to some code using a DOM, perhaps XmlDocument (if xhtml) or the HTML Agility Pack (otherwise), looking at all //@src or //@href attributes.