blacklister/token.php

<?php
class token {
    private $db = null;

    public function __construct() {
        $this->db = new db();
    }

    private function getRole($token) {
        $dbAction = $this->db->prepare("SELECT role FROM clients WHERE token = ?");
        $dbAction->bind_param('s',$token);
        $dbAction->execute();
        $dbAction->store_result();
        $dbAction->bind_result($role);
        $dbAction->fetch();
        if ($dbAction->num_rows() == 1){
            return $role;
        }
        return false;
    }

    public function isAdmin($token) {
        if($this->getRole($token) == 'admin') {
            return true;
        }
        return false;
    }

    public function isClient($token) {
        if($this->getRole($token) == 'client') {
            return true;
        }
        return false;
    }
}