JS - Sort a table with stocks into groups using the Footable plugin and jQuery

sort-stock-portfolio-table.js

// sort the table after window object is done loading
jQuery(window).ready(function($){
  var $ = jQuery;
  // sort Portfolio table by the portfolio group
  sort_portfolio_group();
});

// sort the portfolio by group and by the selected sorting order
function sort_portfolio_group(){
  var $ = jQuery;
  // hide the tradeview charts that are current showing and append them to page
  $('.tradeview').text('Trading Chart');
  $('.tradeview_row').remove();
  
  var load_tables = sort_tables();
  
  load_tables.then(function(promise){
      $('table.footable').css('visibility','hidden');
      $('table.footable').css('display','table');
      // apply the resized columns to the shown footables
      $('.footable').each(function(){
          var footable = $(this).data('footable');
          footable.resize();
        });
      return promise;
    }).done(function(){
      var window_size = $('table.footable').outerWidth();
      if( window_size <= footable_breakpoints.phone ){
        //expand_portfolio_group();

      }
      $('table.footable').css('visibility','visible');
      $('.pt_preloader').remove();
   });
  
}

// deferred function to call after page load to increase perceived load speed
function sort_tables(){

  var $ = jQuery;
  var deferred = $.Deferred();
  
  $('table.footable').each(function(){
    var table_id = $(this).attr('id');
    var current_footable = $(this);
    var duplicateChk = {};
    $('#'+table_id+' tr').each(function(){
      var portfolio_group = $(this).attr('id');
      // check to see if duplicate portfolio group names are in the table
      
      if (typeof portfolio_group !== typeof undefined && portfolio_group !== false) {
        var portfolio_group_row = $(this);
        var first_row = $('#'+table_id+' tr[data-group='+portfolio_group+']').first();
        var i = 0;
        var last_row_selected = null;
        $('#'+table_id+' tr[data-group='+portfolio_group+']').each(function(){
          if( i != 0 ){
            // append each member of the group after the previous member of the group
            $(last_row_selected).after($(this));
          }
          last_row_selected = $(this);
          i++;
        });
        // after grouping all members of the portfolio group together, add the group name before the first member of the group
        $(first_row).before(portfolio_group_row);

      }

    });
  });
  deferred.resolve();

  return deferred.promise();
};