* This file is licensed under the Affero General Public License version 3 or
* later.
* See the COPYING-README file.
*/
/**
* wrapper for server side events (http://en.wikipedia.org/wiki/Server-sent_events)
* includes a fallback for older browsers and IE
*
* use server side events with caution, to many open requests can hang the server
*/
class OC_EventSource implements \OCP\IEventSource {
/**
* @var bool
*/
private $fallback;
/**
* @var int
*/
private $fallBackId = 0;
/**
* @var bool
*/
private $started = false;
protected function init() {
if ($this->started) {
return;
}
$this->started = true;
// prevent php output buffering, caching and nginx buffering
OC_Util::obEnd();
header('Cache-Control: no-cache');
header('X-Accel-Buffering: no');
$this->fallback = isset($_GET['fallback']) and $_GET['fallback'] == 'true';
if ($this->fallback) {
$this->fallBackId = (int)$_GET['fallback_id'];
header("Content-Type: text/html");
echo str_repeat('' . PHP_EOL, 10); //dummy data to keep IE happy
} else {
header("Content-Type: text/event-stream");
}
if (!OC_Util::isCallRegistered()) {
$this->send('error', 'Possible CSRF attack. Connection will be closed.');
$this->close();
exit();
}
flush();
}
/**
* send a message to the client
*
* @param string $type
* @param mixed $data
*
* @throws \BadMethodCallException
* if only one parameter is given, a typeless message will be send with that parameter as data
*/
public function send($type, $data = null) {
if ($data and !preg_match('/^[A-Za-z0-9_]+$/', $type)) {
throw new BadMethodCallException('Type needs to be alphanumeric ('. $type .')');
}
$this->init();
if (is_null($data)) {
$data = $type;
$type = null;
}
if ($this->fallback) {
$response = '' . PHP_EOL;
echo $response;
} else {
if ($type) {
echo 'event: ' . $type . PHP_EOL;
}
echo 'data: ' . OCP\JSON::encode($data) . PHP_EOL;
}
echo PHP_EOL;
flush();
}
/**
* close the connection of the event source
*/
public function close() {
$this->send('__internal__', 'close'); //server side closing can be an issue, let the client do it
}
}