Send periodic message to connected clients?

[carys-cc]

Hi,

I'd like to send periodic messages every 120s can't figure out how to tie timers and sockets together. I tried writing something like this but it's definitely not working. New to ReactPHP and would appreciate any guidance.

$socket->on('connection', function ($conn) use ($loop) {
    $func = function () use ($conn) {$conn->close();};
    $timer = $loop->addPeriodicTimer(120, function() use(&$conn));
    $conn->on('data', function ($data) use ($loop, &$timer, $func) {
       // do other stuff like connect to mysql to pull some data
       $echo 'got here';
       $connection->write('this is a periodic message');
    });
});

$loop->run();

[clue]

@PatrickChoi Hi and welcome to ReactPHP :-)

You can simply start a new periodic timer for each new connection (and also make sure to stop this timer once the connection closes again) like this:

$socket->on('connection', function (ConnectionInterface $conn) use ($loop) {
    // create a new timer that sends a message every N seconds
    $timer = $loop->addPeriodicTimer(120, function () use ($conn) {
        $conn->write('this is a periodic message');
    });

    // stop timer when connection closes
    $conn->on('close', function () use ($timer, $loop) {
        $loop->cancelTimer($timer);
    });
});

I hope this helps 👍

I believe this has been answered, so I'm closing this for now. Please come back with more details if this problem persists and we can reopen this 👍

[carys-cc]

This worked perfectly thank you. Have a question about variables, seems within the $loop->addPeriodicTimer variables cannot be accessed that have been defined in $socket->on function.

Is there any way for these two parts of the code to communicate?

[clue]

Sure! PHP does not bind variables from the outer scope automatically to Closure functions, but you can explicitly use any number of variables:

$socket->on('connection', function (ConnectionInterface $conn) use ($loop) {
    // create a new timer that sends a message every N seconds
    $i = 0;
    $timer = $loop->addPeriodicTimer(120, function () use ($conn, &$i) {
        $conn->write('this is a periodic message ' . ++$i);
    });

    // stop timer when connection closes
    $conn->on('close', function () use ($timer, $loop) {
        $loop->cancelTimer($timer);
    });

    // react to incoming data
    $conn->on('data', function ($chunk) use (&$i) {
        $conn->write('received ' . strlen($chunk) . ' after message ' . $i);
    });
});