Pimcore\Web2Print\Processor::startPdfGeneration PHP Method

    public function startPdfGeneration($documentId)
    {
        $jobConfigFile = $this->loadJobConfigObject($documentId);
        $document = $this->getPrintDocument($documentId);
        // check if there is already a generating process running, wait if so ...
        Model\Tool\Lock::acquire($document->getLockKey(), 0);
        try {
            \Pimcore::getEventManager()->trigger("document.print.prePdfGeneration", $document, ["processor" => $this]);
            $pdf = $this->buildPdf($document, $jobConfigFile->config);
            file_put_contents($document->getPdfFileName(), $pdf);
            \Pimcore::getEventManager()->trigger("document.print.postPdfGeneration", $document, ["filename" => $document->getPdfFileName(), "pdf" => $pdf]);
            $creationDate = \Zend_Date::now();
            $document->setLastGenerated($creationDate->get() + 1);
            $document->save();
        } catch (\Exception $e) {
            $document->save();
            Logger::err($e);
        }
        Model\Tool\Lock::release($document->getLockKey());
        Model\Tool\TmpStore::delete($document->getLockKey());
        @unlink($this->getJobConfigFile($documentId));
    }