C# ASP.Net Playing with HTML - Automatic Tag Closer

 When we have to deal with HTML strings and sometimes have to split it for Read More text. So, there is a posibility to have open tags which result the total page to collapse. Therefore we might need an automatic tag closer for a splitted HTML string. The following class would do the needful.

   public class TagCloser  
   {  
     private Stack<string> _openTags = new Stack<string>();  
     private string _html;  
     private int _currentCharIndex;  
     private bool Eof  
     {  
       get { return _currentCharIndex == _html.Length - 1; }  
     }  
     private int _pendingTagNameStartIndex;  
     private string _pendingTagName;  
     private int _currentEndTagStartIndex;  
     private State _state;  
     public string CloseTags(string html)  
     {  
       if (string.IsNullOrEmpty(html))  
         return html;  
       _html = html;  
       _currentCharIndex = -1;  
       while (!Eof)  
       {  
         var ch = ReadNext();  
         if (_state == State.InTagName)  
         {  
           // Self closing  
           if (ch == '/' && PeekNext() == '>')  
           {  
             ReadNext();  
             _state = _openTags.Count > 0 ? State.InsideTag : State.None;  
             continue;  
           }  
           if (ch == ' ' || ch == '>')  
           {  
             _pendingTagName = _html.Substring(_pendingTagNameStartIndex, _currentCharIndex - _pendingTagNameStartIndex);  
           }  
           if (ch == ' ')  
           {  
             _state = State.InAttributes;  
           }  
           else if (ch == '>')  
           {  
             _openTags.Push(_pendingTagName);  
             _state = State.InsideTag;  
           }  
         }  
         else if (_state == State.InsideTag)  
         {  
           if (ch == '<' && PeekNext() == '/')  
           {  
             _currentEndTagStartIndex = _currentCharIndex;  
             ReadNext();  
             _state = State.InEndTag;  
             continue;  
           }  
           if (ch == '<')  
           {  
             _state = State.InTagName;  
             _pendingTagNameStartIndex = _currentCharIndex + 1;  
             continue;  
           }  
         }  
         else if (_state == State.InEndTag)  
         {  
           if (ch == '>')  
           {  
             _openTags.Pop();  
             _state = _openTags.Count > 0 ? State.InsideTag : State.None;  
           }  
         }  
         else  
         {  
           if (ch == '<')  
           {  
             _state = State.InTagName;  
             _pendingTagNameStartIndex = _currentCharIndex + 1;  
             continue;  
           }  
         }  
       }  
       // Broken start tag  
       if (_state == State.InTagName || _state == State.InAttributes)  
       {  
         _html = _html.Substring(0, _pendingTagNameStartIndex - 1);  
       }  
       // Broken end tag  
       else if (_state == State.InEndTag)  
       {  
         _html = _html.Substring(0, _currentEndTagStartIndex);  
       }  
       var sb = new StringBuilder();  
       sb.Append(_html);  
       while (_openTags.Count > 0)  
       {  
         var tag = _openTags.Pop();  
         sb.Append("</" + tag + ">");  
       }  
       return sb.ToString();  
     }  
     private char ReadNext()  
     {  
       return Eof ? '\0' : _html[++_currentCharIndex];  
     }  
     private char PeekNext()  
     {  
       return Eof ? '\0' : _html[_currentCharIndex + 1];  
     }  
     enum State  
     {  
       None, InTagName, InAttributes, InsideTag, InEndTag  
     }  
   }  

And you may refer it as below;

 new TagCloser().CloseTags(c.headerLinkDisplay160.Trim())  

Happy coding...