// Somewhat messy code to implement the Multi-Sort… I'm sure this could be done using some kind of index and not resorting to Regular Expressions to manipulate strings

function multiSort(index, iCol, sortorder)

{

 if (jQuery('#multisortcheckbox').is(':checked'))

 {

  var Column = jQuery('#grid')[0].p.colModel;

  jQuery("#grid").setGridParam({sortname: colModel[0]['index'], sortorder: 'asc'});

  if (multiSort.sortName == '')

  {

   multiSort.sortName = Column[iCol].index;

   multiSort.sortOrder = sortorder;

  }

  else

  {

   var RegEx = new RegExp('s*' + Column[iCol].index + 's*', 'i');

   if (RegEx.test(multiSort.sortName)) // Test if column already selected in Multi-Sort collection

   {

    RegEx = new RegExp('s*' + Column[iCol].index + ' ([ade]+sc)s*', 'i');

    if (RegEx.test(multiSort.sortName)) // Test if NOT last field in sort list

    {

     var colSortOrder = RegEx.exec(multiSort.sortName);

     colSortOrder = ((colSortOrder && colSortOrder[1] == 'asc') ? 'desc' : 'asc'); // Toggle Column Sort Order since this is not retained when moving from one column to the next in Multi-Sort mode

     RegEx = new RegExp('(s*' + Column[iCol].index + ') [ade]+scs*', 'i');

     multiSort.sortName = multiSort.sortName.replace(RegEx, '$1 ' + colSortOrder);

    }

    else multiSort.sortOrder = ((multiSort.sortOrder == 'asc') ? 'desc' : 'asc'); // If last field in sort list then change sort order (Toggle Column Sort Order since this is not retained when moving from one column to the next in Multi-Sort mode)

   }

   else

   {

    multiSort.sortName = multiSort.sortName + ' ' + multiSort.sortOrder + ', ' + Column[iCol].index;

    multiSort.sortOrder = sortorder;

   }

  }

  jQuery("#grid").setGridParam({sortname: multiSort.sortName, sortorder: multiSort.sortOrder});

 }

}

multiSort.sortName = '';

multiSort.sortOrder = '';

// Toggle multi-sort mode

jQuery("#multisortcheckbox").change(function()

{

 var Column = jQuery('#grid')[0].p.colModel;

 if (!jQuery('#multisortcheckbox').is(':checked'))

 {

  jQuery("#grid").setGridParam({sortname: colModel[0]['index'], sortorder: 'asc'});

  multiSort.sortName = '';

  multiSort.sortOrder = '';

 }

});

// Add a Multi-Sort checkbox after the Grid Refresh button in the Pager bar

jQuery('td#refresh_grid').after('<td id="multisortcell"><span id="multisort" title="Toggle Column Multi-Sorting"><label for="multisortcheckbox" style="padding: 0 3px 0 10px; cursor: pointer;">Multi-Sort</label><input id="multisortcheckbox" type="checkbox" class="ui-pg-input" style="vertical-align: middle; cursor: pointer;"/></span></td>'); // Add the "Multi-Sort" checkbox to the footer bar

// Construct the jqGrid component

jQuery("#grid").jqGrid

({

  …

  onSortCol: function(index, iCol, sortorder){multiSort(index, iCol, sortorder);}, // jqGrid onSortCol event handler

  …

});

// Create the SQL sort statement in the PHP web service

$SortIndex = isset($_GET['sidx'])?$_GET['sidx']:(isset($_POST['sidx'])?$_POST['sidx']:'');

$SortOrder = isset($_GET['sord'])?$_GET['sord']:(isset($_POST['sord'])?$_POST['sord']:1);

$Order = '';

$Comma = '';

$SortIndices = explode(',', $SortIndex);

foreach ($SortIndices as $SortValue)

{

 $SortValues = explode(' ', trim($SortValue));

 foreach ($SortValues as $SortField)

 {

  if ($SortField == 'desc' || $SortField == 'asc') $Order .= ' ' . $SortField;

  else $Order .= $Comma . '[' . $SortField . ']';

 }

 $Comma = ', ';

}

$Order .= ' ' . $SortOrder; // $Order contains the full SQL sort string