MPDF not working when devmode is not enabled

Question

I have an issue with generation a pdf with MPDF.

Everything is working fine when devmode is on. When I try it on production it can't load the pdf. When I set devmode true on production it's working again. Normally it should be the opposite since we are developing with devmode on.

Anyone have a idea what could be the issue?

Edit: I'm using Craft CMS 3, it's happening aswell on my local environment when I set the .env file to production.

Answer 1

Not a full answer, but a possible workaround.

I was able to get the Super PDF plugin to work regardless of Dev Mode. It uses dompdf under the hood, but something in the way it is implemented bypasses whatever the underlying issue is.

https://github.com/amici-infotech/craft-super-pdf

Answer 2

I've finally fixed my issue.

My initial function to generate the PDF's was:

class PdfVariable
{
    public function generate($html, $name, $toBrowser = true)
    {
        try
        {
        
            $defaultConfig = (new \Mpdf\Config\ConfigVariables())->getDefaults();
  

            $_mpdf = new \Mpdf\Mpdf([
                'mode' => 'utf-8',
                'format' => 'A4-P',
    
            ]);

            $_mpdf->shrink_tables_to_fit = 1;

            $_mpdf->WriteHTML($html);

            if($toBrowser)
            {
                // Shows pdf in browser (for development)
                //$_mpdf->Output($name . '.pdf', \Mpdf\Output\Destination::DOWNLOAD);
                $_mpdf->Output();
            }
            else
            {
                // Downloads
                $_mpdf->Output($name . '.pdf', \Mpdf\Output\Destination::DOWNLOAD);

            }
        }
        catch(Exception $e)
        {
            echo $e->getMessage();
        }

        if($toBrowser)
        {
            exit(0);
        }
    }
}

Somehow this piece of code

if($toBrowser)
{
    exit(0);
}

Causes it to crash when the environment is set to staging/production. If set to 'dev' it will still function normally with this piece of code.

Still find it weird it gave no errors whatsoever in the Craft CMS logs.

Hope I can help someone out with this.

Answer 3

I can also confirm that using a template hook instead of a twig variable doesn't help.

I also downgraded Craft to 4.0.6 and that also has no affect.

Answer 4

Wow, I just had the exact same problem pop up and have been debugging for hours and hours and this is the first time I've found any indication that it's not just me. Here's what I know, but I have no solutions so far...

• I can reproduce locally, so I don't think it's a server issue.
• I also don't think it's a file permission issue, getting the same result if I'm saving files locally or just sending them inline to the browser.
• MPDFs WriteText method also doesn't work, so I don't think it's an HTML parsing issue.
• Similarly, I've reduced what I'm trying to do to just a Hello World string of text, so I don't think it's anything about the document itself.

Similarly no errors, the PDF is created, it's just empty/doesn't render.

There is nothing documented about Craft's Dev Mode that seems like it would have any affect on this.

BTW, my implementation uses a custom module that really just comes down to a twig variable function. I feel like that's the only thing that even kind of related to dev mode. The function runs when that route is hit. In my reduced test case it passes no parameters. It obviously runs regardless of the mode.

Craft CMS Version: 4.3.6.1

MPDF: 8.1.2