Calculate end date based on start date and duration

Question

My goal is to calculate and show end date based on my start date by date picker and doprdown to choose number of weeks.

I have Jquery datetimepicker http://xdsoft.net/jqplugins/datetimepicker/ to select start date and dropdown to select number of weeks.

I'm using below codes to get the end date result but its not working:

  week_number_id.on('change', function(e) {
var selectvalue = $(this).val();
//Display 'loading' status in the target select list
date_result_id.html('<i class="uk-icon-spinner uk-icon-spin"></i>');
if (selectvalue == '') 
{
    date_result_id.html(initial_date_result_html);
} 
else 
{
    //Make AJAX request, using the selected value as the GET
    $.ajax({
        url: 'index.php',
        data:'option=com_mycom&task=getmydateHTML&dvalue='+selectvalue,
        success: function(output) {
            date_result_id.html(output);
            updateSelect(date_result_id.val());
        },
        error: function (xhr, ajaxOptions, thrownError) {
            alert(xhr.status +  ' ' + thrownError);
        }
    });
}
});

and on php code:

  public function getmydateHTML() {
  $jinput = JFactory::getApplication()->input;
  $db = JFactory::getDbo();
  $query = $db->getQuery(true);         
  $dt = $jinput->get ('dvalue');
  $choosendate = $jinput->get ('start_date');       
  $newdate = strtotime("+". $dt . "week", $choosendate);
  echo   date('M d, Y', $newdate);     
 exit; // this will stop Joomla processing, and not output template modules   etc.
   }

But after calculation result shows date starting from jan 01, 1970, weeks are increasing correctly but the code can not get the start date.

Answer 1

Your script doesn't send 'start_date' parameter anywhere, so it defaults to 01.01.1970. Add 'start_date' parameter to $.ajax data, or add default value to $jinput->get('start_date', some_default_val).

BTW. - exit; is not a good practice, there are better methods: https://stackoverflow.com/a/13479338/2877359

Answer 2

As the previous answer stated, the start_date parameter is not sent through the data field.

In any case, I don't know why are querying the server for this simple task - you can do this at the client's end. See this SO answer about this.