从Slim 3中间件返回自定义对象

Question

I'm writing an API in Slim 3 that integrates with a legacy system. The client sends a token to my API in the querystring. I want to write a middleware that will authenticate the token and return an object that contains the necessary internal login credentials (which are different from the token) that are used by the legacy system.

I can authenticate the token now, but my problem is that Slim 3 requires that the middleware return a \Psr\Http\Message\ResponseInterface instance. I also want it to return a custom object back to the application.

I think I can achieve this by re-verifying the token outside of the middleware, and only use the middleware as a way to authenticate the token and return an error if it fails. I tend to think this kludgy way could be avoided so I just have to use the token once in the middleware and return the custom object at the same time so I don't have to use the token twice.

I have searched around for solutions, but all of the example middlewares I can find are similar to https://github.com/julionc/slim-basic-auth-middleware, where they are simply authenticating in the middleware but do not have the requirement to return a custom object. The documentation at http://www.slimframework.com/docs/concepts/middleware.html doesn't seem to help much either with this custom requirement.

Any ideas?

Answer 1

You could include a callback in your middleware which you can use to store the custom object somewhere. For example with slim-jwt-auth you can use callback to store the decoded contents of JWT using a callback.

$app->add(new \Slim\Middleware\JwtAuthentication([
    "secret" => "supersecretkeyyoushouldnotcommittogithub",
    "callback" => function ($request, $response, $arguments) use ($app) {
        $app->jwt = $arguments["decoded"];
    }
]));

Note that this kind of callback is not a Slim 3 feature. Just something this middleware happens to use.