Tạo dịch vụ API trong PHP, PHP API rest

CREATE TABLE IF NOT EXISTS `users` 
( 
`user_id` int(11) NOT NULL AUTO_INCREMENT, 
`user_fullname` varchar(25) NOT NULL, 
`user_email` varchar(50) NOT NULL, 
`user_password` varchar(50) NOT NULL, 
`user_status` tinyint(1) NOT NULL DEFAULT '0', 
PRIMARY KEY (`user_id`) 
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;

require_once("Rest.inc.php"); 

class API extends REST 
{ 
public $data = ""; 
const DB_SERVER = "localhost"; 
const DB_USER = "Database_Username"; 
const DB_PASSWORD = "Database_Password"; 
const DB = "Database_Name"; 

private $db = NULL; 

public function __construct() 
{ 
parent::__construct();// Init parent contructor 
$this->dbConnect();// Initiate Database connection 
} 

//Database connection 
private function dbConnect() 
{ 
$this->db = MySQL_connect(self::DB_SERVER,self::DB_USER,self::DB_PASSWORD); 
if($this->db) 
MySQL_select_db(self::DB,$this->db); 
} 

//Public method for access api. 
//This method dynmically call the method based on the query string 
public function processApi() 
{ 
$func = strtolower(trim(str_replace("/","",$_REQUEST['rquest']))); 
if((int)method_exists($this,$func) > 0) 
$this->$func(); 
else 
$this->response(',404); 
// If the method not exist with in this class, response would be "Page not found".
} 

private function login() 
{ 
.............. 
} 

private function users() 
{ 
.............. 
} 

private function deleteUser() 
{ 
............. 
} 

//Encode array into JSON 
private function json($data) 
{ 
if(is_array($data)){ 
return json_encode($data); 
} 
} 
} 

// Initiiate Library 
$api = new API; 
$api->processApi(); 
?>

private function login() 
{ 
// Cross validation if the request method is POST else it will return "Not Acceptable" status 
if($this->get_request_method() != "POST") 
{ 
$this->response(',406); 
} 

$email = $this->_request['email']; 
$password = $this->_request['pwd']; 

// Input validations 
if(!empty($email) and !empty($password)) 
{ 
if(filter_var($email, FILTER_VALIDATE_EMAIL)){ 
$sql = MySQL_query("SELECT user_id, user_fullname, user_email FROM users WHERE user_email = '$email' AND user_password = '".md5($password)."' LIMIT 1", $this->db); 
if(MySQL_num_rows($sql) > 0){ 
$result = MySQL_fetch_array($sql,MySQL_ASSOC); 

// If success everythig is good send header as "OK" and user details 
$this->response($this->json($result), 200); 
} 
$this->response(', 204); // If no records "No Content" status 
} 
} 

// If invalid inputs "Bad Request" status message and reason 
$error = array('status' => "Failed", "msg" => "Invalid Email address or Password"); 
$this->response($this->json($error), 400); 
} 

private function users() 
{ 
// Cross validation if the request method is GET else it will return "Not Acceptable" status 
if($this->get_request_method() != "GET") 
{ 
$this->response(',406); 
} 
$sql = MySQL_query("SELECT user_id, user_fullname, user_email FROM users WHERE user_status = 1", $this->db); 
if(MySQL_num_rows($sql) > 0) 
{ 
$result = array(); 
while($rlt = MySQL_fetch_array($sql,MySQL_ASSOC)) 
{ 
$result[] = $rlt; 
} 
// If success everythig is good send header as "OK" and return list of users in JSON format 
$this->response($this->json($result), 200); 
} 
$this->response(',204); // If no records "No Content" status 
}

 
RewriteEngine On 
RewriteCond %{REQUEST_FILENAME} !-d 
RewriteCond %{REQUEST_FILENAME} !-s 
RewriteRule ^(.*)$ api.php?rquest=$1 [QSA,NC,L] 

RewriteCond %{REQUEST_FILENAME} -d 
RewriteRule ^(.*)$ api.php [QSA,NC,L] 

RewriteCond %{REQUEST_FILENAME} -s 
RewriteRule ^(.*)$ api.php [QSA,NC,L]