基于会话的消息不在类中工作

Question

I have a main file (framework.php) that requires a few classes. For simplicity of my question lets assume only messages with the class Messages and automate with the class Automate. The messages class stores session messages that appear to the user on the frontend whenever they refresh their page .etc. When I add a message in Automate I do so via $msg = new Messages; $msg->add('s', 'Hello World!'); However I keep repeating $msg = new Messages everytime I want to add a $msg, and because this is messy, I want to just call the class once. So I initialize the class in the constructor like so:

class Automate
{
    protected $msg;
    //public $connection;
    public $cke;
    public $debug = false;
    public $disallow_insert;
    public $bImgUp = BACKEND_IMAGE_UPLOAD_PATH;
    public $fImgUp = FRONTEND_IMAGE_UPLOAD_PATH;
    public function __construct() {
        global $disallow_insert;
        $this->disallow_insert = $disallow_insert;
        $this->cke = (bool) self::ckeCheck();
        $this->msg = new Messages();

    }

and in my main file I add it $msg = new Messages(); so I can just call the display function echo $msg->display();

However this method does not work (no errors, but still), the only thing that seems to work is when I initialize the $msg = new Messages(); before every add or display. What am I doing wrong?

I should mention I'm using this session based message script.

UPDATE: I have determined the the messages are getting added by commenting out the clear function in the messages class. It almost seems as though the variable is getting unset before displaying.

Answer 1

I figured it out after researching OOP practices. I made the messages class a singelton via:

public static function getInstance()
{
    static $instance = NULL;
    if (NULL === $instance) {
        $instance = new static();
    }

    return $instance;
}

and in my classes

var $msg;
public function __construct() {
    $this->msg = Messages::getInstance();
}

I figure the messages class needed to be constructed once, not multiple times which is why the function clear kept being called!