HTTP

An HTTP server turns each Swoole request into a PSR-7 request, runs it through the middleware chain, and then dispatches a RequestEvent. A listener on that event creates the response. The HTTP flow is the same as in other Windwalker HTTP components, so middleware and listeners work the same way.

Request Flow

For every request, the server:

1. Creates the PSR-7 request. The request carries a swoole attribute with the native request, response, connection ID (fd), and server.
2. Runs the middleware chain. The last step dispatches RequestEvent.
3. Sends RequestEvent::$response and dispatches ResponseEvent.
4. Dispatches ErrorEvent if an exception is thrown.

If no listener sets a response, the server sends an empty 200 response. That default hides mistakes, so check the response in tests.

Handling Requests

RequestEvent is the main extension point. Its request is a PSR-7 request, and its response is the response to send:

use Windwalker\Http\Event\RequestEvent;
use Windwalker\Reactor\Swoole\SwooleHttpServer;

$server = new SwooleHttpServer();

$server->onRequest(function (RequestEvent $event) use ($server) {
    $path = $event->request->getUri()->getPath();
    $factory = $server->getHttpFactory();

    $event->response = $factory
        ->createResponse(200)
        ->withBody(
            $factory->createStream("Path: $path")
        );
});

The request is immutable. To pass data to other listeners, store it in $event->attributes. Add a response listener with onResponse() to change or log the response after it is built.

Middleware

Middleware are PSR-15 objects with a process() method. Each one receives the request and the next handler. It can change the request, return a response itself, or pass control on by calling the handler:

$server->middleware(MyAuthMiddleware::class);

A string is created through the container, and any extra arguments are passed to its constructor. Middleware run in the order they are added. A middleware that returns a response without calling the handler stops the chain, so the request listener does not run.

Errors

When a listener throws, the server dispatches ErrorEvent. If no listener stops propagation, the exception is rethrown and reaches Swoole's error handling. If a listener stops propagation, the exception is swallowed and the server sends nothing. Your listener must then write the response through $event->output.

Output

Responses are written by an output object. The default is SwooleOutput, which writes the status line, headers, and body to the native Swoole response. Replace it with setOutputBuilder() only if you need to change how responses are written.