Psr7Middlewares\Middleware\Csrf::__invoke PHP Method

    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next)
    {
        if (!self::hasAttribute($request, ClientIp::KEY)) {
            throw new RuntimeException('Csrf middleware needs ClientIp executed before');
        }
        if (Utils\Helpers::getMimeType($response) !== 'text/html') {
            return $next($request, $response);
        }
        $tokens =& self::getStorage($request, self::KEY);
        if (Utils\Helpers::isPost($request) && !$this->validateRequest($request, $tokens)) {
            return $response->withStatus(403);
        }
        $generator = function ($action = null) use($request, &$tokens) {
            if (empty($action)) {
                $action = $request->getUri()->getPath();
            }
            return $this->generateTokens($request, $action, $tokens);
        };
        if (!$this->autoInsert) {
            $request = self::setAttribute($request, self::KEY_GENERATOR, $generator);
            return $next($request, $response);
        }
        $response = $next($request, $response);
        return $this->insertIntoPostForms($response, function ($match) use($generator) {
            preg_match('/action=["\']?([^"\'\\s]+)["\']?/i', $match[0], $matches);
            return $match[0] . $generator(isset($matches[1]) ? $matches[1] : null);
        });
    }