Relay Response Middleware

This package include the following Relay-compatible response middleware:

• ResponseSender to send a PSR-7 response
• ExceptionHandler to handle exceptions from subsequent middleware
• FormContentHandler to deserialize the URL-encoded payload of a PSR-7 request
• JsonContentHandler to deserialize the JSON payload of a PSR-7 request
• JsonDecoder to deserialize the JSON payload of a PSR-7 request (deprecated)

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

ResponseSender

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 Relay queue, instantiate it directly ...

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

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

ExceptionHandler

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

JsonContentHandler

Again, the JsonContentHandler does what it sounds like: it deserializes the JSON payload of a PSR-7 request object and makes the parameters available in subsequent middleware decorators.

The JsonContentHandler checks the incoming request for a method other than GET and for an application/json or application/vnd.api+json Content-Type header. If it finds both of these, it parses the JSON and makes it available as the parsed body of the $request before passing it and the $response to $next. If the method is GET or the Content-Type header defines a different mime type, the JsonContentHandler ignores the $request and continues the chain.

To add the JsonContentHandler to your queue, instantiate it directly...

$queue = new \Relay\Middleware\JsonContentHandler();

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

To access the decoded parameters in subsequent middleware, use the getParsedBody() method of the $request

$decodedJsonData = $request->getParsedBody();

FormContentHandler

FormContentHandler works almost identically to JsonContentHandler, but parses payloads of requests that have application/x-www-form-urlencoded as the Content-Type.

JsonDecoder

NOTE: This handler has been deprecated in favor of JsonContentHandler!

Again, the JsonDecoder does what it sounds like: it deserializes the JSON payload of a PSR-7 request object and makes the parameters available in subsequent middleware decorators.

The JsonDecoder checks the incoming request for a method other than GET and for an application/json Content-Type header. If it finds both of these, it decodes the JSON and makes it available as the parsed body of the $request before passing it and the $response to $next. If the method is GET or the Content-Type header does not specify application/json, the JsonDecoder does nothing with the $request and passes it and the $response to $next.

To add the JsonDecoder to your queue, instantiate it directly...

$queue = new \Relay\Middleware\JsonDecoder();

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

To access the decoded parameters in subsequent middleware, use the getParsedBody() method of the $request

$decodedJsonData = $request->getParsedBody();