Extenions to js Datatables - RowGouping

I need a generic extension to the JS DATATABLES sript. [login to view URL] What i need is a generic extension to add row groups with a subtotal. Do see what this means take a look at this [login to view URL] So i need the possibility to add a new paramter to the $columns array for server-side processing, where i can specify the columns to group. There must be the possibility to add more than one column. Example ( [login to view URL] ) $columns = array(     array( 'db' => 'first_name', 'dt' => 0 ),     array( 'db' => 'last_name',  'dt' => 1 ),     array( 'db' => 'position',   'dt' => 2 ),     array( 'db' => 'office',     'dt' => 3 , 'groupBy' => 'desc', ),     array(         'db'        => 'start_date',         'dt'        => 4, 'groupby' => 'asc',         'formatter' => function( $d, $row ) {             return date( 'jS M y', strtotime($d));         }     ),     array(         'db'        => 'salary',         'dt'        => 5, 'summed' => 'yes',         'formatter' => function( $d, $row ) {             return '$'.number_format($d);         }     ) ); So again all needed features : - extension to the "js datatables" script - must work with Server-Side-Processing - must work with all tables ( generic ) - add groupedby columns (this is not a MYSQL GROUP BY ) - add sum functions to the footer - add subtotals for each groupedb column, if there is a summed column - must work with the PDF export function from the tabletools I need this in about 24 hours. You have to work on your own server. For testing you can use the Northwind Database : [login to view URL] [login to view URL] ( MYSQL )