Get seleted text parent tag using regex C#

Question

 <SPAN id=spanD121C150D2 style="BACKGROUND-COLOR: antiquewhite" CategoryID="1" MessageID="2316" refSpan="">
 <SPAN id=span1CE69EDE12 style="BACKGROUND-COLOR: blue" CategoryID="2" MessageID="2316" refSpan="">platnosci inny srodkiem platnosci. DC - zakup paliwa na stacji benzynowej 101-500 (150 zl). 27 
 </SPAN>
 </SPAN>

I have a string like above.

If the selected text is "srodkiem ", is it possible to get the relevant span tag?

Is this possible using a regular expression?

Answer 1

this this possible using regex ? p

No. Use an HTML parser.

Answer 2

Yes, it's possible with regex, but you should to use Html Agility Pack. Using that will be much less painful to maintain your code.

Answer 3

I wrote a small function with HTML Agility pack:

  public static HtmlNode GetNodeByInnerText(string sHTML, string sText)
  {
      HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
      doc.LoadHtml(sHTML);
      int Position = sHTML.ToString().IndexOf(sText);
      return FindNodeByPosition(doc.DocumentNode, Position);
  }

  private static HtmlNode FindNodeByPosition(HtmlNode node, int Position)
  {
      HtmlNode foundNode = null;
      foreach (HtmlNode child in node.ChildNodes)
      {
          if (child.StreamPosition <= Position &
              ((child.NextSibling == null) || child.NextSibling.StreamPosition > Position))
          {
              if (child.ChildNodes.Count > 0 &
                  !(child.ChildNodes.Count == 1 && child.InnerHtml == child.FirstChild.InnerHtml))
              {
                  foundNode = FindNodeByPosition(child, Position);
                  break; // TODO: might not be correct. Was : Exit For
              }
              else
              {
                  return child;
              }
          }
      }
      return foundNode;
  }