HTML viewhelper should allow CSS files from other extension's Private folder

[liayn]

Describe the bug

It is not possible to use CSS files for HTMLViewHelper, which are located in a Resources/Private folder of an extension.

Environment
TYPO3 version(s): v12+
pdfviewhelpers version: v3.0.0

Steps to reproduce

Configure in TypoScript:

styleSheet = EXT:myext/Resources/Private/some/path/styles.css

Expected behavior

The stylesheet is loaded.

Possible solution

Adjust the code part in https://github.com/bithost-gmbh/pdfviewhelpers/blob/main/Classes/ViewHelpers/HtmlViewHelper.php#L97 to:

if (!empty($this->arguments['styleSheet'])) {
            try {
                $styleSheetFile = $this->conversionService->convertFileSrcToFileObject($this->arguments['styleSheet']);
                $styleSheetContent = $styleSheetFile->getContents();
            } catch (ValidationException $e) {
                $styleSheetFile = GeneralUtility::getFileAbsFileName($this->arguments['styleSheet']);
                if (!$styleSheetFile) {
                    throw $e;
                }
                $styleSheetContent = file_get_contents($styleSheetFile);
            }

            $htmlStyle = '<style>' . $styleSheetContent . '</style>';
        }

If the CSS file can't be found via FAL, try directly loading it.

[maechler]

@liayn Thank you very much for that detailed bug report and providing a fix! I'll need to have a closer look at this use case and the failing test, but probably the solution will be to adjust the test logic. I can take care of this, let me know in case you'd need a quick fix.

[liayn]

The use case is rather simple: Nothing should be public that does not need to be public. In case of CSS for a PDF: No need to go public.

(Actually this is basically the same for every local resource used when rendering PDF.)

[maechler]

Yes, I totally agree with the benefits of this! I was more concerned with the failing test, because with this change we do not throw a ValidationException anymore when the file does not exist. Thinking more about it, I would replace the exception rethrow with the following to fix the test and stay consistent with the current error handling:

if (!is_file($styleSheetFile)) {
    throw new ValidationException('Provided styleSheet file path "' . $styleSheetFile . '" does not exist. ERROR: 1729546062', 1729546062, $e);
}

What do you think?

[liayn]

We should probably use PathUtility::isExtensionPath($persistenceIdentifier) first.
There is no need to go through FAL at all, if a resource stems from an extension.