This package include the following Relay-compatible middleware:

• ResponseSender to send a PSR-7 response
• ExceptionHandler to handler exceptions from subsequent middleware

This package is installable and PSR-4 autoloadable via Composer as relay/middleware.

The ResponseSender does just what it sounds like: it sends the PSR-7 response object.

The ResponseSender does nothing with the $request or $response, passing them immediately to $next. Afterwards, it takes the returned $response and sends it using header() and echo, and returns the sent $response.

The ResponseSender is intended to go at the top of the Relay queue, so that it is the middleware with the last opportunity to do something with the returned response.

To add the ResponseSender to your Real queue, instantiate it directly ...

$queue[] = new \Relay\Middleware\ResponseSender();

... or use a $resolver of your choice to instantiate it from the $queue.

Similarly, the ExceptionHandler does what it sound like: it catches any exceptions that bubble up through the following middleware decorators.

The ExceptionHandler does nothing with the $request or $response, and passes them directly to $next inside a try/catch block. If no exception bubbles up, it returns the $response from $next. However, if it catches an exception, it returns an entirely new $response object with the exception message and an HTTP 500 status code. It then returns the new $response object.

The ExceptionHandler is intended to go near the top of the Relay queue, but after the ResponseSender, so that the ResponseSender can then send the returned $response.

To add the ExceptionHandler to your queue, instantiate it directly with an empty $response implementation object ...

$queue = new \Relay\Middleware\ExceptionHandler(new ResponseImplementation());

... or use a $resolver of your choice to instantiate it from the $queue.