gistfile1.txt

/**
     * This action return content for the balloon popups on the map
     *
     * @return ViewModel
     */
    public function balloonAction()
    {
        $reference = $this->params()->fromQuery('reference');
        $type = $this->params()->fromQuery('type');

        /* @var \AcsiMap\Poi\PoiProviderInterface $poiProvider */
        $poiProvider = $this->getPoiProviderPluginManager()->get('campsite');

        $viewModel = $poiProvider->getBalloon($type, $reference);
        $viewModel->setTerminal(true);
        return $viewModel;

    }

$baloonModel = $poiProvider->getBalloon($type, $reference);
return (new ViewModel)->addChild($balloonModel, 'baloon')->setTerminal(true);