use event-source to make a progress bar of demo

$eventSource = new EventSource;
$lastEventId = $eventSource->getLastEventId();
$eventSource
	->setLastEventId(1)
	->setData([])
	->setEvent('ProgressEvent')
	->setRetry(1000)
	->output();

_EventSource("demo.php",
	[
		{
			//Custom Event
			event:'ProgressEvent',
			callback:function(data)
			{
				//code...
			}
		},
		{
			//default Event
			callback:function(data)
			{
			}
		}
	]);