Gantt Chart in module

This page refers to the timeline package and loads it thus:

var chart = new google.visualization.Timeline(container);

Is this not available in the module?

I have solved this by writing a module.

My code is below, and is for a site using Organic Groups where an OG content type has a date field with a start and end date.

It would be great if someone can pick this up as a starting point for an add-on module to create TimeLine type Google Charts.

Glenn

<?php
function mymodule_create_gantt_chart() {
  ?>
  <script type="text/javascript" src="https://www.google.com/jsapi?autoload={'modules':[{'name':'visualization','version':'1','packages':['timeline']}]}"></script>
  <script type="text/javascript">
    google.setOnLoadCallback(drawChart);

    function drawChart() {
      var container = document.getElementById('gantt');

      var chart = new google.visualization.Timeline(container);

      var dataTable = new google.visualization.DataTable();
  
      var name;
      var start;
      var end;
  
      dataTable.addColumn({ type: 'string', id: 'Task' });
      dataTable.addColumn({ type: 'date', id: 'Start' });
      dataTable.addColumn({ type: 'date', id: 'End' });
  
      <?php   
        $node = node_load(arg(1));
        $project = node_load($node->og_group_ref[$node->language][0]['target_id']);
        $query = new EntityFieldQuery();
        $query
          ->entityCondition('entity_type', 'node')
          ->entityCondition('bundle', 'oa_event')
          ->fieldCondition('og_group_ref', 'target_id', $project->nid);
        $tasks = $query->execute();

        foreach ($tasks['node'] as $tasknode) {
          $node = node_load($tasknode->nid);
          $task = $node->title;
          $start = $node->field_oa_date[$node->language][0]['value'];
          $end = $node->field_oa_date[$node->language][0]['value2']; ?>
  
          name = "<?php echo $task;?>";
          start = "<?php echo date('Y, m, d', $start);?>";
          end = "<?php echo date('Y, m, d', $end);?>";

          dataTable.addRows([[ name, new Date(start), new Date(end) ]]);
          <?php
        } ?>
      chart.draw(dataTable);
    }
  </script>
  <?php return '<div id="gantt" style="width: 100%; height: auto;"></div>';
}