title: Get all column values from paginated jQuery DataTable with serverSide set to true
body: <p>I am trying to implement the <code>footerCallback</code> to find the sum of all elements in one of the columns of my paginated data table. When I try to calculate the total amount in all the pages, only the sum of rows in the current page is being calculated. My code for footerCallback is as follows: </p>
  
  <pre><code>"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;
                              };
  
                              // Total over all pages
                              total = api
                              .column( 5 )
                              .data()
                              .reduce( function (a, b) {
                                  return intVal(a) + intVal(b);
                              }, 0 );
  
                              // Total over this page
                              pageTotal = api
                                  .column( 5, { page: 'current'} )
                                  .data()
                                  .reduce( function (a, b) {
                                      return intVal(a) + intVal(b);
                                  }, 0 );
  
                              // Update footer
                              jQuery( api.column( 5 ).footer() ).html(
                                  '$'+pageTotal +' ( $'+ total +' total)'
                              );
                          }
  </code></pre>
  
  <p>This function is given in the ajax call along with columns and columndefs. Both, pageTotal and total are returning the same value. When I try the <code>table.column( "#header5" ).data();</code> command in the console, even it is returning just the data in the current page.  In one of the websites, I read that, when server side is given true, <code>data()</code> and <code>fnGetData()</code> returns just the data in the current page. Is that true? If yes, how can I get the data in other pages?</p>