SSESymfonyExample

$response = new StreamedResponse(function () {
    while (true) {
        echo 'event: message' . PHP_EOL;
        echo 'data: ' . \json_encode(['data' => 1]) . PHP_EOL;
        echo PHP_EOL . PHP_EOL;
        ob_flush();
        flush();
        sleep(2);
    };
});

$response->headers->set('Content-Type', 'text/event-stream;charset=utf-8');
$response->headers->set('Cache-Control', 'no-cache');
$response->headers->set('X-Accel-Buffering', 'no');