<?php

abstract class RoleChecker {

    /**
     * @var RoleChecker
     */
    protected $nextCheck;

    abstract public function check(UserRole $userRole);

    public function next(UserRole $userRole)
    {
        if ($this->nextCheck) {
            $this->nextCheck->check($userRole);
        }
    }

    public function setNextChecker(RoleChecker $checker)
    {
        $this->nextCheck = $checker;
    }
}

class UserRole {

    public $type;

    public $date;
}

class AdminCheck extends RoleChecker {

    public function check(UserRole $userRole)
    {
        if (!$userRole->type != 'ADMIN') {
            throw new Exception('User Not Admin');
        }

        $this->next($userRole);
    }
}

class RegistrationDate extends RoleChecker {


    public function check(UserRole $userRole)
    {
        if (strtotime($userRole->date) > strtotime('2018-01-01')) {
            throw new Exception('2018 Users only.');
        }

        $this->next($userRole);
    }

}

$role = new UserRole();
$role->type = 'ROLE_USER';
$role->date = '2017-01-01';

$adminCheck = new AdminCheck();
$registrationCheck = new RegistrationDate();
$adminCheck->setNextChecker($registrationCheck);

$adminCheck->check($role);