phpexcel pdf rendering library has not been defined - pdf

Question

After trying and failing to generate PDFs with PHPExcel 1.7.6 (out of memory errors), I upgraded to 1.7.8. I can't for the life of me figure out how to get it working. I've tried tcPDF and mPDF, and it's the same for both.
Putting it back to Excel output, I can see I'm setting the path correctly. All I can get is "PDF Rendering library has not been defined", and I can't figure out what it wants - I've tried 'mPDF5.4', 'MPDF54' (the actual name of the folder itself), 'mpdf', 'mpdf.php'...same each time.
I've been using PHPExcel for over a year, so I'm not entirely new to it. I've lost way more time than I care to admit on this problem, and I haven't found this problem described anywhere, so I'm feeling more than a little stupid that I appear to be the only one that can't figure this out.
The actual code I'm using is the following:
ini_set('include_path', ini_get('include_path').'\\Classes\\');
$rendererName = PHPExcel_Settings::PDF_RENDERER_MPDF;
$rendererLibrary = 'mPDF5.4';
$rendererLibraryPath = ini_get('include_path') . $rendererLibrary;
(That is, pretty well a copy of the example code.)
In the interest of completeness, the headers I'm using are
echo header("Content-Type: application/pdf");
echo header("Content-Disposition: attachment; filename=".$filename.".pdf" );
echo header('Cache-Control: max-age=0');
These near the top of the file, naturally.
Near the end of the file, the output code is
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'PDF');
$objWriter->save('php://output');

Answer 1

I got it working. Much as I'd like to say I had a breakthrough moment and understand it perfectly, I have no idea how I got it to work. However, in hopes that it might help someone, let me lay out what I did.
I'm running XAMPP on Windows. My file structure has the folder for PHPExcel itself in xampp\php\PEAR\Classes. domPDF is in the same folder, and I renamed it 'dompdf'.
For reasons I no longer recall, I set the include path like so:
ini_set('include_path', ini_get('include_path').'\\Classes\\');
To set the rendering path, I used the following:
$rendererName = PHPExcel_Settings::PDF_RENDERER_DOMPDF;
$rendererLibrary = 'dompdf';
$rendererLibraryPath = ini_get('include_path') . $rendererLibrary;
For the actual writer creation, I'm using the following:
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'PDF');
$objWriter->save($path.$fullFileName);
One thing I noticed that may have made things different was doing this:
// include 'PHPExcel/Writer/Excel2007.php';
That is, unlike everything I've done in PHPExcel, I'm not including anything from the Writer folder at all. Best I can remember, that's all that's different this time versus a week ago when I asked the question. Once I'd grabbed the 01simple-download-pdf.php file from the Tests folder in 1.7.8, it was mostly a matter of copying the code from it and tweaking it to my paths.
To summarize, leave $rendererName alone. The $rendererLibrary is the name of the folder that contains the library, 'dompdf' in my case. The $rendererLibraryPath is literally setting the path to that folder, so it ends with the path that contains the pdf library folder.
It should be obvious that I'm no uber-leet hax0r, but SO has answered many, many programming questions for me. I'm hoping this helps someone else, so they're not wasting hours like I did.

Answer 2

The PHPOffice contains also PHPWord. I have had the same error message with PHPWord. This is for LINUX. A replacement of 'PhpWord' by 'PhpExcel' should do the job for this case. You must modify the path $rendererLibraryPath to your needs.
$rendererName = \PhpOffice\PhpWord\Settings::PDF_RENDERER_DOMPDF;
$rendererLibraryPath = realpath(__DIR__ . '/../../../../../dompdf-0.6.1');
\PhpOffice\PhpWord\Settings::setPdfRenderer($rendererName, $rendererLibraryPath);
$objWriter = \PhpOffice\PhpWord\IOFactory::createWriter($phpWord, 'PDF');
$objWriter->save('helloWorld.pdf');

Answer 3

If you are getting this error and you have set the correct path to the TCPDF or DOMPDF folder (you do not have to write the full path), then also make sure you have these lines:
if (!PHPExcel_Settings::setPdfRenderer(
$rendererName,
$rendererLibraryPath
)) {
die(
'NOTICE: Please set the $rendererName and $rendererLibraryPath values' .
EOL .
'at the top of this script as appropriate for your directory structure'
);
}