php-basics/src/Traits/Singleton.php

72 lines
2.0 KiB
PHP

<?php
/**
* Useful PHP Basics
* Copyright (C) 2023 Sebastian Meyer <sebastian.meyer@opencultureconsulting.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
declare(strict_types=1);
namespace OCC\Basics\Traits;
use LogicException;
/**
* Allows just a single instance of the class using this trait.
*
* @author Sebastian Meyer <sebastian.meyer@opencultureconsulting.com>
* @package opencultureconsulting/basics
*/
trait Singleton
{
/**
* Holds the singleton instances.
*/
private static array $singleton = [];
/**
* Get a singleton instance of this class.
*
* @param mixed ...$args Constructor parameters
*/
final public static function getInstance(mixed ...$args): static
{
if (!isset(static::$singleton[static::class])) {
static::$singleton[static::class] = new static(...$args);
}
return static::$singleton[static::class];
}
/**
* This is a singleton class, thus the constructor is private.
*
* Usage: Get an instance of this class by calling self::getInstance()
*
* @param mixed ...$args Constructor parameters
*/
abstract private function __construct(mixed ...$args);
/**
* This is a singleton class, thus cloning is prohibited.
*
* @throws \LogicException
*/
final public function __clone(): void
{
throw new LogicException('Cloning of a Singleton is prohibited.');
}
}