Excluding middleware from Slim route - php

Question

Per http://www.slimframework.com/docs/concepts/middleware.html, one can add middleware to an application, route, or group.
How should one add middleware to all routes (i.e. to the application), but exclude it from specific routes?
EDIT. As a possible solution, I am thinking of adding some logic in my application middleware to bypass the middleware functionality. Getting the method is easy enough using $request->getMethod(), however, the other URL methods described by http://www.slimframework.com/docs/objects/request.html are not available in the middleware.

Answer 1

I think you need to add middleware to group of route, sample admin route group and user group.
If you would like to change the behaviour of dynamic you have to modify your middleware logic to check your specific request,
sample your route returns JSON if client set type of request.
EDIT:
$app = new \Slim\App();
//pass $app to middleware
$app->add(function ($request, $response, $next) use ($app) {
//do what you want with $app.
//reads config file with routes for exclude
$response = $next($request, $response);
return $response;
});
$app->get('/', function ($request, $response, $args) {
$response->getBody()->write(' Hello ');
return $response;
});
$app->run();

Answer 2

I believe, as of writing this post (I'm using Slim 3.12.1), the answer to your question is it's not possible to remove a previously added middleware from a route.
The solution suggested by the accepted answer makes middleware implementation tightly coupled with route definition. If route (or in similar suggested solution, route name) changes, then middleware code needs to change as well. This is due to the fact that the middleware is technically not removed from route middleware stack. This gets complicated in some situations. For example, if the middleware is written by someone else. You probably want to avoid changing code of a third party library, so it's possible that you end up extending the third party middleware to override its functionality in some way, or some similar solution, yet to make the implementation coupled with your route definitions.
My suggestion is, instead of changing the logic of your middleware to prevent its execution for some routes, add logic to your code to control which middlewares should be added to which routes. Here is a fully functional example to demonstrate how to add a common middleware to all routes while adding some middlewares only to some specific routes but not all (the ones you meant to exclude). To keep things simple, there is no logic for determining which middlewares should be added to which routes, but this demonstrates the general idea. Here are the assumptions:
paths starting with /user should be protected by Authorization middleware
/user/login and /user/signup are exceptions and do not need to be protected by Authentication middleware. Instead, we want to allow login/signup attempts from specific IP addresses only, so we need to protect this route with IP Access Control middleware
all requests to all paths starting with /user should be logged using Logger middleware (no exception here)
other routes don't need any middleware (so we should avoid using $app->add())
<?php
require __DIR__ . '/../vendor/autoload.php';
$app = new Slim\App;
// A simple middleware to write route path and middleware name
class SampleMiddleware
{
public function __construct($name)
{
$this->name = $name;
}
public function __invoke($request, $response, $next)
{
$response->write($request->getUri()->getPath() . ' invokes ' . $this->name . "\n");
return $next($request, $response);
}
}
// Three middleware instances with different names
$auth = new SampleMiddleware('Authorization');
$ipAC = new SampleMiddleware('IP Access Control');
$logger = new SampleMiddleware('Logger');
$group = $app->group('/user', function($app) {
$app->get('/profile', function($request, $response, $args){
return $response;
});
$app->get('/messages', function($request, $response, $args){
return $response;
});
})->add($auth)
->add($logger);
$group = $app->group('/user', function($app) {
$app->get('/login', function($request, $response, $args){
return $response;
});
$app->get('/signup', function($request, $response, $args){
return $response;
});
})->add($ipAC)
->add($logger);
$app->get('{p:.*}', function($request, $response, $args){
$response->write('No middleware for ' . $request->getUri()->getPath());
return $response;
});
$app->run();
Output:
/user/profile
/user/profile invokes Logger
/user/profile invokes Authorization
/user/login
/user/login invokes Logger
/user/login invokes IP Access Control
/something/else
No middleware for /something/else

Answer 3

You can access the uri inside middleware with the following.
$uri = $request->getUri()->getPath();
With that information you can return from the middleware early if the $uri matches path you want to exclude from the middleware.

Answer 4

If you want to add a global middleware the easiest way to achieve this is the following.
$app->group('', function () {
//Add your routes here, note that it is $this->get() ... etc inside the closure
})->add(MyNewMiddlewareClass::class);