SingletonTrait.php

<?php
/**
 * SingletonTrait.php
 *
 * @date        28/02/2014
 * @file        SingletonTrait.php
 */

trait SingletonTrait
{
    /**
     *  protected
     */
    protected function __construct(){
        if(method_exists($this, 'init')) {
            $this->init();
        }
    }

    /**
     * @var static
     */
    protected static $instance;

    /**
     * @return static
     */
    public static function getInstance()
    {
        if(!static::$instance) {
            static::$instance = new static;
        }
        return static::$instance;
    }

    public function __clone()
    {
        throw new Exception('Object follows singleton pattern and cannot be cloned');
    }

}