Documentation / Middleware / Callback

Websocket: Callback middleware

This middleware will apply callback functions on certain actions. This middlewares is included in library and can be added to provide additional functionality.

$client_or_server
    ->addMiddleware(new WebSocket\Middleware\Callback(
        incoming: function (WebSocket\Middleware\ProcessStack $stack, WebSocket\Connection $connection): WebSocket\Message\Message {
            $message = $stack->handleIncoming(); // Get incoming message from next middleware
            $message->setContent("Changed message");
            return $message;
        },
        outgoing: function (WebSocket\Middleware\ProcessStack $stack, WebSocket\Connection $connection, WebSocket\Message\Message $message): WebSocket\Message\Message {
            $message->setContent('Changed message');
            $message = $stack->handleOutgoing($message); // Forward outgoing message to next middleware
            return $message;
        },
        httpIncoming: function (WebSocket\Middleware\ProcessHttpStack $stack, WebSocket\Connection $connection): WebSocket\Http\Message {
            $message = $stack->handleHttpIncoming(); // Get incoming message from next middleware
            return $message;
        },
        httpOutgoing: function (WebSocket\Middleware\ProcessHttpStack $stack, WebSocket\Connection $connection, WebSocket\Http\Message $message): WebSocket\Http\Message {
            $message = $stack->handleHttpOutgoing($message); // Forward outgoing message to next middleware
            return $message;
        },
        tick: function (WebSocket\Middleware\ProcessTickStack $stack, WebSocket\Connection $connection): void {
            $stack->handleTick(); // Forward tick to next middleware
        }
    ));

• The incoming and outgoing callbacks MUST return a Message instance
• The httpIncoming and httpOutgoing callbacks MUST return a HTTP request/response instance respectively
• The tick callback returns nothing

The handleIncoming, handleOutgoing, handleHttpIncoming, handleHttpOutgoing and handleTick methods will pass initiative further down the middleware stack.