BaseModel.php

<?php

abstract class BaseModel extends Object
{

	/** @var Model instance */
	static $register = array();



	public static function getInstance($class)
	{
		if( !isset(self::$register[$class]) OR !(self::$register[$class] instanceof BaseModel) ){
			self::$register[$class] = new $class;
		}

		return self::$register[$class];
	}


	public function getName()
	{
		return preg_replace("#Model$#", '', get_class($this));
	}

	// ...

}

BasePresenter.php

<?php

abstract class BasePresenter extends Presenter
{

	/** @var Object */
	private $model;

	public $oldLayoutMode = False;
	public $oldModuleMode = False;



        public function getModel($modelName = Null)
        {
		if( !empty($modelName) ){
			$class = str_replace(":", "_", $modelName)."Model";
			$model = callback($class, 'getInstance')->invokeArgs($class);

			return $model;
		}

        	if( !($this->model instanceof BaseModel) ){
			$name = $this->getName();
			$class = str_replace(":", "_", $name)."Model";

			$this->model = callback($class, 'getInstance')->invokeArgs($class);
		}

		return $this->model;
        }

        // ...

}