title: Using jQuery Datatable's fnFooterCallback after adding data using fnAddData
body: <p>I'm trying to get the total of my Totals column placed in the footer using "fnFooterCallback" but I'm not having any luck and I keep getting the "Cannot reinitialise Datatable" warning on me.</p>
  
  <p>Here is my HTML code:</p>
  
  <pre><code>        &lt;table id="hours" border="1" class="display dataTable"&gt;
              &lt;thead&gt;
                  &lt;tr&gt;
                      &lt;th&gt;
                          Order Number
                      &lt;/th&gt;
                      &lt;th&gt;
                          Machine
                      &lt;/th&gt;
                      &lt;th&gt;
                          Start
                      &lt;/th&gt;
                      &lt;th&gt;
                          Stop
                      &lt;/th&gt;
                      &lt;th&gt;
                          Total
                      &lt;/th&gt;
                      &lt;th&gt;
                          Edit
                      &lt;/th&gt;
                  &lt;/tr&gt;
              &lt;/thead&gt;
              &lt;tbody&gt;                    
              &lt;/tbody&gt;   
              &lt;tfoot&gt;
                  &lt;tr&gt;
                      &lt;th&gt;
                          Total:
                      &lt;/th&gt;
                  &lt;/tr&gt;
              &lt;/tfoot&gt;
          &lt;/table&gt;
  </code></pre>
  
  <p>any my jQuery code:</p>
  
  <pre><code>for (var i = 0; i &lt; item.length; i++) {
      // add the data to the tbody
      var oTable = $("#hours").dataTable().fnAddData([
                                      item[i].OrderNumber,
                                      item[i].MachineName,
                                      item[i].startTime,
                                      item[i].stopTime,
                                      item[i].totalTime,
                                      item[i].editButton
                                  ]);
  
  }
  // after the data is added, get the total of the Totals Column
  oTable = $("#hours").dataTable(  
      {
          "fnFooterCallback": function (nRow, aaData, iStart, iEnd, aiDisplay) {
                   var total = 0;
                          for (var i = 0; i &lt; aaData.length; i++) {
                              total += aaData[i][4] * 1;
                          }
  
                          var page = 0;
                          for (var i = iStart; i &lt; iEnd; i++) {
                              page += aaData[aiDisplay[i]][4] * 1;
                          }
  
                          /* Modify the footer row to match what we want */
                          var nCells = nRow.getElementsByTagName('th');
                          nCells[1].innerHTML = parseInt(page);
          }
          });
  </code></pre>
  
  <p>I know creating a second call to dataTable is my problem, but I'm not sure how else to call the "fnFooterCallback" after I've added data using dnAddData</p>