/**
* Batch print shipping labels for whole shipments.
* Push pdf document with shipping labels to user browser
*
* @param AbstractCollection $collection
* @return ResponseInterface|ResultInterface
*/
protected function massAction(AbstractCollection $collection)
{
$labelsContent = [];
if ($collection->getSize()) {
/** @var \Magento\Sales\Model\Order\Shipment $shipment */
foreach ($collection as $shipment) {
$labelContent = $shipment->getShippingLabel();
if ($labelContent) {
$labelsContent[] = $labelContent;
}
}
}
if (!empty($labelsContent)) {
$outputPdf = $this->labelGenerator->combineLabelsPdf($labelsContent);
return $this->fileFactory->create('ShippingLabels.pdf', $outputPdf->render(), DirectoryList::VAR_DIR, 'application/pdf');
}
$this->messageManager->addError(__('There are no shipping labels related to selected shipments.'));
return $this->resultRedirectFactory->create()->setPath('sales/shipment/');
}