/**
* JSON middleware invokable class. It forces Content-Type on the response
* to be application/json. If the request Content-Type is not json then
* return the response with status 415 (Unsupported Media Type)
*
* @param \Psr\Http\Message\ServerRequestInterface $request PSR7 request
* @param \Psr\Http\Message\ResponseInterface $response PSR7 response
* @param callable $next Next middleware
*
* @return \Psr\Http\Message\ResponseInterface
*/
public function __invoke(Request $request, Response $response, $next)
{
$mediaType = $request->getMediaType();
$method = strtolower($request->getMethod());
if (in_array($method, ['post', 'put', 'patch']) && '' !== (string) $request->getBody()) {
if (empty($mediaType) || $mediaType !== 'application/json') {
return $response->withStatus(415);
}
}
$response = $response->withHeader('Content-type', 'application/json');
$response = $next($request, $response);
return $response;
}