public function & SetHelper ($helperName, & $instance, $forAllTemplates = TRUE) {
		/** @var $this \MvcCore\View */
		$implementsIHelper = FALSE;
		if ($forAllTemplates) {
			if (self::$_toolClass === NULL)
				self::$_toolClass = \MvcCore\Application::GetInstance()->GetToolClass();
			$toolClass = self::$_toolClass;
			$helpersInterface = self::HELPERS_INTERFACE_CLASS_NAME;
			$className = get_class($instance);
			$implementsIHelper = $toolClass::CheckClassInterface($className, $helpersInterface, FALSE, FALSE);
			self::$_globalHelpers[$helperName] = [& $instance, $implementsIHelper];
		}
		$this->__protected['helpers'][$helperName] = & $instance;
		if ($implementsIHelper) $instance->SetView($this);
		return $this;
	}