Fixed unnecessary alert dan other bugs.

src/controller/LoginController.php

@@ -14,6 +14,8 @@ class LoginController
     {
         session_start();
 
+        $userData = null;
+
         if (isset($_POST['username'])) {
             $username = $_POST['username'];
             $password = md5($_POST['password']);
@@ -27,14 +29,15 @@ class LoginController
             exit;
         }
 
-        if (isset($userData)) {
+        if ($userData !== null && $userData instanceof User) {
             if ($userData->password === $password) {
                 $_SESSION['username'] = $username;
-
                 echo "<script type='application/javascript'> alert('Login berhasil'); </script>";
             } else {
-                echo "<script type='application/javascript'> alert('Username atau password salah'); </script>";
+                echo "<script type='application/javascript'> alert('Password salah.'); </script>";
             }
+        } else if ($userData !== null) {
+            echo "<script type='application/javascript'> alert('Username tidak terdaftar.'); </script>";
         }
 
         require __DIR__."/../view/login.php";

src/model/User.php

@@ -70,7 +70,7 @@ class User {
             $stmt = $conn->prepare("SELECT * FROM user WHERE $attribute='$value'");
             $stmt->execute();
 
-            $user = $stmt->fetchObject();
+            $user = $stmt->fetchObject("User");
             return $user;
         } catch (PDOException $e) {
             echo "Error: ".$e->getMessage();