Singleton — Base Singleton Pattern

File: src/Singleton.php Namespace: Magrathea2 Type: Abstract Class

The base class for all manager/service classes in the framework. Ensures a class can only have one instance per process. Most framework classes (Config, Database, Logger, Debugger, MagratheaCache, etc.) extend Singleton.

Properties

Methods

Instance(): static

Returns the single shared instance of the calling class. Creates it on the first call.

use Magrathea2\Config;

$config = Config::Instance();
// Always the same object
$config === Config::Instance(); // true

MockClass($mocker): static

Replaces the instance with a mock/stub object. Used for testing.

$mock = new FakeDatabase();
Database::MockClass($mock);
// Now Database::Instance() returns $mock

SetInstance($inst): void

Directly sets the stored instance. Lower-level alternative to MockClass.

Constructor & Cloning

All these are intentionally restricted:

final private function __construct()  // can't be manually instantiated
final protected function __clone()    // can't be cloned
final public function __wakeup()      // can't be unserialized

This ensures that only Instance() can create the object.

Creating Your Own Singleton

<?php
namespace App\Services;

use Magrathea2\Singleton;

class MyService extends Singleton {
    private string $data = "";

    public function SetData(string $d): static {
        $this->data = $d;
        return $this;
    }

    public function GetData(): string {
        return $this->data;
    }
}

MyService::Instance()->SetData("hello");
echo MyService::Instance()->GetData(); // "hello"

Notes

• The $instance array is keyed by class name (via static::class), so subclasses each get their own instance.
• MockClass is especially useful in unit tests when you want to swap in a fake implementation.

Class Reference — Singleton

Class for Singleton handling