How to setup Notification Messages in PHP OOP

I'm working on CMS with PHP OOP. In this project I have added a feature where admins of a Website can add and manage other admins. In order to add an admin, I have created this page which is called `admin_new.php` and goes like this:

<?php
if (isset($_POST['submit'])){
$username = $_POST['uname'];
$email = $_POST['email'];
$password = $_POST['pass'];
$groups = $_POST['groups'];
if($groups == "Main Admin"){
$level = 1;
}else if($groups == "Administrator"){
$level = 2;
}else if($groups == "Content Creator"){
$level = 3;
}else if($groups == "Social Media Manager"){
$level = 4;
}else{
$level = 5;
}
if (filter_var($email, FILTER_VALIDATE_EMAIL) === false) {
$notice['email_validation'] = "The email that you have entered is not a valid one";
}else{
$registration = new Register();
$notices = $registration->CheckUname($username,$email,$password,$groups,$level)->getNotices();
}
}
?>
<div class="content-wrapper">
<section class="content-header">
<h1>
Add New Admin
<small>You can add new admin here</small>
</h1>
<ol class="breadcrumb">
<li class="active">addnewadmin.php</li>
</ol>
</section>
<section class="content">
<div class="row">
<div class="col-md-6">
<div class="box box-primary">
<div class="box-header with-border">
<h3 class="box-title">Required Information</h3>
</div>
<?php
if(isset($notice['email_validation'])) {
echo "
<div class='alert alert-danger'>
<strong>Hey!</strong> ".$notice['email_validation'].".
</div>
";
}
if(isset($notice['username_exists'])) {
echo "
<div class='alert alert-danger'>
<strong>Hey!</strong> ".$notice['username_exists'].".
</div>
";
}
if(isset($notice['email_exists'])) {
echo "
<div class='alert alert-danger'>
<strong>Hey!</strong> ".$notice['email_exists'].".
</div>
";
}
if(isset($notice['success_message'])) {
echo "
<div class='alert alert-success'>
<strong>Hey!</strong> ".$notice['success_message'].".
</div>
";
}
?>
<form role="form" method="POST" action="">
<div class="box-body">
<div class="form-group">
<label>User name</label>
<input type="text" class="form-control" placeholder="Enter username" name="uname" required>
</div>
<div class="form-group">
<label for="exampleInputEmail1">Email address</label>
<input type="email" class="form-control" id="exampleInputEmail1" placeholder="Enter email" name="email" required>
</div>
<div class="form-group">
<label for="exampleInputPassword1">Temporary password</label>
<input type="password" class="form-control" id="exampleInputPassword1" placeholder="Enter password" name="pass" required>
</div>
<div class="form-group">
<label>Group admin</label>
<select class="form-control" name="groups">
<option value="Main Admin">Main Admin</option>
<option value="Administrator">Administrator</option>
<option value="Content Creator">Content Creator</option>
<option value="Social Media Manager">Social Media Manager</option>
<option value="Analyst">Analyst</option>
</select>
</div>
</div>
<div class="box-footer">
Visit <a href="https://zite.pouyavagefi.com/documentation/types.php">admin types</a> documentation to know the differences between each admin.
</div>
<div class="box-footer">
<button name="submit" type="submit" class="btn btn-primary">Submit</button>
</div>
</form>
</div>
</div>
</div>
</section>
</div>

And the class that I had used in this file is called `Register.class.php` and contains this:

<?php
class Register
{
protected $notice = array();
private $db;
public function __construct()
{
$this->db = new Connection();
$this->db = $this->db->dbConnect();
}
public function CheckUname($username,$email,$password,$groups,$level)
{
if(!empty($username)&&!empty($email)&&!empty($password)&&!empty($groups)&&!empty($level))
{
$chk1 = $this->db->prepare("SELECT username FROM admins WHERE user_name= ?");
$chk1->bindParam(1,$username);
$chk1->execute();
if($chk1->rowCount() == 1)
{
$notice['username_exists'] = "Try different username";
return $notice;
}else{
$chk2 = $this->db->prepare("SELECT email FROM admins WHERE email_address= ?");
$chk2->bindParam(1,$email);
$chk2->execute();
if($chk2->rowCount() == 1)
{
$notice['email_exists'] = "The email address that you have entered is already exists in database";
return $notice;
}else{
$this->NewAdmin($username,$email,$password,$groups,$level);
$notice['success_message'] = "New admin was successfully added";
return $notice;
}
}
}
}
public function NewAdmin($username,$email,$password,$groups,$level)
{
if(!empty($username)&&!empty($email)&&!empty($password)&&!empty($groups)&&!empty($level))
{
$reg = $this->db->prepare("INSERT INTO admins (user_name, email_address, password_hash, group_admin, date_joined, admin_level) VALUES ( ?, ?, ?, ?, NOW(), ?)");
$reg->bindParam(1,$username);
$reg->bindParam(2,$email);
$reg->bindParam(3,$password);
$reg->bindParam(4,$groups);
$reg->bindParam(5,$level);
$reg->execute();
}
}
public function getNotices()
{
return $this->notice;
}
}
?>

Basically all I want to do is to make sure that:

1- Username does not exists in db

2- User didn't enter an email which already exists in db

3- And if everything goes well, then add a new row to the table

And when I run this and fill the form with dummy info to check how to *notices* appear, I get this error message:

**Fatal error: Uncaught Error: Call to a member function getNotices() on array in**
**admin_new.php:22**

**Stack trace: addnewadmin.php(20): require_once()**

# 1 {main} thrown in admin_new.php on line 22

And line 22 of `admins_new.php` is this:

$notices = $registration->CheckUname($username,$email,$password,$groups,$level)->getNotices();

How do I fix this?

Problem is in concepts.. what is what

`$registration` -> instace of class **Register**
`CheckUname($username,$email,$password,$groups,$level)` -> function which return array **$notice**

> Basically ur method `CheckUname()` returns `$notices` and u call on
> this array method `getNotices()` and it's problem..

If u wanna get `$notices` u must call public method on `$registration` instance.

$registration->CheckUname($username,$email,$password,$groups,$level);
$notices = $registration->getNotices()

or

$notices = $registration->CheckUname($username,$email,$password,$groups,$level);