Sending PDF via email works when command run on console, but not when run by a cron job

Question

I've become stuck, I want to send a custom report via email in a pdf format. It's strange because it works correctly when I run the command via the console, but when it's run via a cron job nothing happens.

I'll appreciate it greatly if someone can point me in the right direction.

P.S. I know the cron functions correctly as it works perfectly if the attachment is a pdf.

Please see my code below.

Many thanks!

        $config = array('auth' => 'login',
            'username' => 'someemail@gmail.co.uk',
            'password' => 'somepassword',
            'ssl' => 'tls');

        $transport = new \Zend_Mail_Transport_Smtp('smtp.gmail.com', $config);

        $mail = new \Zend_Mail();
        $mail->setBodyText("Hello, please see " . $fileName . " attached.");
        $mail->setSubject($fileName . " " . $this->getNextDeliveryDate());
        $mail->setFrom('someemail@gmail.co.uk', $fileName . $this->getNextDeliveryDate()); 
        $mail->addTo('someemail@gmail.co.uk', 'Info'); 
        $mail->addTo('someemail2@gmail.co.uk', '');

        $fileContents = fopen($this->directory->getAbsolutePath($filepath), 'r');
        $attachment = new \Zend_Mime_Part($fileContents);
        $attachment->type = 'application/pdf';
        $attachment->disposition = \Zend_Mime::DISPOSITION_ATTACHMENT;
        $attachment->encoding = \Zend_Mime::ENCODING_BASE64;
        $attachment->filename = $fileName . $this->getNextDeliveryDate() . ".pdf";

        $mail->addAttachment($attachment);

        try {
            $transport->send($mail);
        } catch (\Exception $e) {
          //  var_dump($e->getMessage());
        }
    }

Since posting this, I still haven't had any luck. I've switched it to sending via csv on the corn job and it works perfectly, would anyone know what I'm doing wrong?

Update:

From further investigation, it appears to stop working when this function runs via cron;

    public function generatePDF($itemDataRaw, $filename){

    ksort($itemDataRaw);

    $this->state->setAreaCode(\Magento\Framework\App\Area::AREA_ADMINHTML);
    $html =  $this->_blockFactory->createBlock('Magento\Backend\Block\Template')
        ->setTemplate('Ozark_Managment::stocklist/stock.phtml')
        ->setData('itemDataRaw', $itemDataRaw)
        ->setData("nextDeliveryDate", $this->getNextDeliveryDate())
        ->toHtml();

    // instantiate and use the dompdf class
    $dompdf = new Dompdf();
    $dompdf->loadHtml($html);
    $options = $dompdf->getOptions();
    $options->set(['isRemoteEnabled' => true]);
    $dompdf->setOptions($options);
    // (Optional) Setup the paper size and orientation
    $dompdf->setPaper('A4', 'portrait');

    // Render the HTML as PDF
    gc_collect_cycles();
    gc_disable();
    $dompdf->render();
    gc_enable();
    gc_collect_cycles();


    $name = date('m-d-Y-H-i-s');
    $filepath = 'export/itemsreq/'. $filename . $name . '.pdf';
    $this->directory->create('export/itemsreq');
    $sheet = $dompdf->output();

    $stream = $this->directory->openFile($filepath, 'w+');
    $stream->write($sheet);
    $stream->close();
    return $filepath;
}

Update 2:

I checked the cron_schedule table for the message, and it was "Area Code already set" So I set up a try and except block on the below, and it worked! Now the problem is my PDF is blank!

try {
        $this->state->setAreaCode(\Magento\Framework\App\Area::AREA_ADMINHTML);
    } catch (\Exception $e) {
        var_dump($this->state->getAreaCode());
    }

Answer 1

I've managed to solve this. Basically, what I was finding that when a cron us run, it sets the area code as Crontab, so to get around this I emulate a state under adminhtml area code. Please see my code below.

    public function generatePDF($itemDataRaw, $filename){
    ksort($itemDataRaw);
    $filepath = '';
    try {
       $this->state->emulateAreaCode(
            'adminhtml',
            function () use ($filename, $itemDataRaw, &$filepath) {
                $html =  $this->_blockFactory->createBlock('Magento\Framework\View\Element\Template')
                    ->setTemplate('Vendor_Name::stocklist/stock.phtml')
                    ->setData('itemDataRaw', $itemDataRaw)
                    ->setData("nextDeliveryDate", $this->getNextDeliveryDate())
                    ->toHtml();

                // instantiate and use the dompdf class
                $dompdf = new Dompdf();
                $dompdf->loadHtml($html);
                $options = $dompdf->getOptions();
                $options->set(['isRemoteEnabled' => true]);
                $dompdf->setOptions($options);
                // (Optional) Setup the paper size and orientation
                $dompdf->setPaper('A4', 'portrait');

                // Render the HTML as PDF
                gc_collect_cycles();
                gc_disable();

                //$_SERVER["SCRIPT_FILENAME"] = "";

                $dompdf->render();
                gc_enable();
                gc_collect_cycles();


                $name = date('m-d-Y-H-i-s');
                $filepath = 'export/itemsreq/'. $filename . $name . '.pdf';
                $this->directory->create('export/itemsreq');
                $sheet = $dompdf->output();

                $stream = $this->directory->openFile($filepath, 'w+');
                $stream->write($sheet);
                $stream->close();
            }
        );
    } catch (\Exception $e) {
        var_dump($e->getMessage());
    }

    return $filepath;
}