title: datatable total amount of all pages dont work, just work the current page
body: <p>please help me with this problem. I want to get the total amount of all pages from my datatable but it dont work at all. </p>
  
  <p>The documentation say that,
  api.column( 3 ).data(); // I can get all data like this
  api.column( 3, {page: "current"} ).data(); // I can get just the current page</p>
  
  <p>But I am putting in this way (api.column( 3 ).data()) and dont work to get all data from all pages, It is as I am putting api.column( 3, {page: "current"} ).data(); only;</p>
  
  <p>Here the code:</p>
  
  <pre><code> $(document).ready(function() {
  
   //datatables
   table = $('#table').DataTable({ 
  
      "processing": true, //Feature control the processing indicator.
      "serverSide": true, //Feature control DataTables' server-side processing mode.
      "order": [], //Initial no order.
  
      // Load data for the table's content from an Ajax source
      "ajax": {
          "url": "&lt;?php echo site_url('Locacao/ajax_list')?&gt;",
          "type": "POST"
      },
      "pageLength": 10,
  
      //Set column definition initialisation properties.
      "columnDefs": [
      { 
          "targets": [ -1 ], //last column
          "orderable": false, //set not orderable
  
      },
      ],              
  
      "footerCallback": function ( row, data, start, end, display ) {
          var api = this.api(), data;
  
          // Remove the formatting to get integer data for summation
          var intVal = function ( i ) {
              return typeof i === 'string' ?
                  i.replace(/[\$,]/g, '')*1 :
                  typeof i === 'number' ?
                      i : 0;
          };         
  
  
          // Update footer            
  
         // Total over all pages
          valor = api
              .column( 3 ) //here should work but nothing
              .data()
              .reduce( function (a, b) {
                  return intVal(a) + intVal(b);
              }, 0 );
  
          // Update footer
          $( api.column( 3 ).footer() ).html(valor);
      }
  
     });
  </code></pre>
  
  <p>Thanks advance!!!</p>