File: include/patterns/Singleton.lib

<?php

/*
    Singleton.lib, DomCore, the WebAbility(r) Core System
    Contains the singleton pattern class
    (c) 2008-2017 Philippe Thomassigny

    This file is part of DomCore

    DomCore 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.

    DomCore 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 DomCore.  If not, see <http://www.gnu.org/licenses/>.
*/

/* @UML_Box -- Do not edit
|------------------------------------------------------------------|
| Singleton : singleton pattern class                              |
|------------------------------------------------------------------|
| - ::instance : array(Singleton)                                  |
|------------------------------------------------------------------|
| + new Singleton()                                                |
| + ::getInstance($name: string): Singleton extended               |
| + ::hasInstance($name: string): boolean                          |
| + __clone(): error thrown                                        |
|------------------------------------------------------------------|
@End_UML_Box */

namespace patterns;

class Singleton extends \core\WAObject
{
  private static $instance = array();

  public function __construct()
  {
    if (isset(self::$instance[get_class($this)]))
      throw new \throwables\PatternError(\core\WAMessage::getMessage('Singleton.noclone').get_class($this));
    parent::__construct();
    self::$instance[get_class($this)] = $this;
  }

  public static function getInstance($classname = null)
  {
    if (!$classname)
      $classname = get_called_class();
    if (!isset(self::$instance[$classname]))
      new $classname();
    return self::$instance[$classname];
  }

  public static function hasInstance($classname = null)
  {
    if (!$classname)
      $classname = get_called_class();
    return isset(self::$instance[$classname]);
  }

  public function __clone()
  {
    throw new \throwables\PatternError(\core\WAMessage::getMessage('Singleton.noclone').get_class($this));
  }

}

?>