Expressive PSR-7 Middleware Layers and Action: How to use it properly and pass data with the request.

BasicMiddleware.php

<?php

namespace App\Middleware;

use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Message\ResponseInterface;

class BasicMiddleware
{
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next)
    {
        // Step 1: Do something (with the request) first
        
        // Step 2: Call the next middleware and wait for the response
        if ($next) {
            $response = $next($request, $response);
        }  
        
        // Step 3: Do something (with the response) before returning the response
        
        // Step 4: Return the response
        return $response;
    }
}

PassingDataMiddleware.php

<?php

namespace App\Middleware;

use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Message\ResponseInterface;

class PassingDataMiddleware
{
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next)
    {
        // Step 1: Do something first
        $data = [
            'foo' => 'bar',  
        ];
        
        // Step 2: Inject data into the request, call the next middleware and wait for the response
        if ($next) {
            $response = $next($request->withAttribute(self::class, $data), $response);
        }  
        
        // Step 3: Do something (with the response) before returning the response
        
        // Step 4: Return the response
        return $response;
    }
}

ReceivingDataMiddleware.php

<?php

namespace App\Middleware;

use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Message\ResponseInterface;

class ReceivingDataMiddleware
{
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next)
    {
        // Step 1: Grab the data from the request and use it
        $data = $request->getAttribute(PassingDataMiddleware::class);
        
        // Step 2: Call the next middleware and wait for the response
        if ($next) {
            $response = $next($request, $response);
        }
        
        // Step 3: Do something (with the response) before returning the response
        
        // Step 4: Return the response
        return $response;
    }
}

XampleAction.php

<?php

namespace App\Action;

use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Message\ResponseInterface;
use App\Middleware\PassingDataMiddleware;

class XampleAction
{
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next)
    {
        // Step 1: Grab the data from the request
        $data = $request->getAttribute(PassingDataMiddleware::class);
        $id = $request->getAttribute('id');
        
        // Step 2: Do some more stuff

        // Step 3: Return the response
        return $response;
    }
}