template/html/jquery-tablesorter.js
function( c, cell, colIndex, txt ) {
         if ( typeof txt === 'undefined' ) {
            txt = ts.getElementText( c, cell, colIndex );
         }
         // if no parser, make sure to return the txt
         var val = '' + txt,
          parser = c.parsers[ colIndex ],
          extractor = c.extractors[ colIndex ];
         if ( parser ) {
            // do extract before parsing, if there is one
            if ( extractor && typeof extractor.format === 'function' ) {
               txt = extractor.format( txt, c.table, cell, colIndex );
            }
            // allow parsing if the string is empty, previously parsing would change it to zero,
            // in case the parser needs to extract data from the table cell attributes
            val = parser.id === 'no-parser' ? '' :
               // make sure txt is a string (extractor may have converted it)
             parser.format( '' + txt, c.table, cell, colIndex );
            if ( c.ignoreCase && typeof val === 'string' ) {
               val = val.toLowerCase();
            }
         }
         return val;
      }
function( c, cell, colIndex, txt ) {
         if ( typeof txt === 'undefined' ) {
            txt = ts.getElementText( c, cell, colIndex );
         }
         // if no parser, make sure to return the txt
         var val = '' + txt,
          parser = c.parsers[ colIndex ],
          extractor = c.extractors[ colIndex ];
         if ( parser ) {
            // do extract before parsing, if there is one
            if ( extractor && typeof extractor.format === 'function' ) {
               txt = extractor.format( txt, c.table, cell, colIndex );
            }
            // allow parsing if the string is empty, previously parsing would change it to zero,
            // in case the parser needs to extract data from the table cell attributes
            val = parser.id === 'no-parser' ? '' :
               // make sure txt is a string (extractor may have converted it)
             parser.format( '' + txt, c.table, cell, colIndex );
            if ( c.ignoreCase && typeof val === 'string' ) {
               val = val.toLowerCase();
            }
         }
         return val;
      }
centralized function to extract/parse cell contents