[FEATURE] Customizable PDF Metadata in ZugferdDocumentPdfMerger

[MarkusJLechner]

Describe the feature

Allow setting custom metadata, specifically the title, when generating PDFs using ZugferdDocumentPdfMerger. The ability to customize other metadata fields (such as subject) should also be considered.

One approach could be to expose the pdfWriter instance so future customizations can be made without requiring new feature requests. Alternatively, make the hardcoded strings inside preparePdfMetadata customizable, ensuring flexibility.

Current Behavior

The current PDF metadata is hardcoded within preparePdfMetadata. Example:

private function preparePdfMetadata(): array
{
    $invoiceInformations = $this->extractInvoiceInformations();

    $dateString = date('Y-m-d', strtotime($invoiceInformations['date']));
    $title = sprintf('%s : %s %s', $invoiceInformations['seller'], $invoiceInformations['docTypeName'], $invoiceInformations['invoiceId']);
    $subject = sprintf('FacturX/ZUGFeRD %s %s dated %s issued by %s', $invoiceInformations['docTypeName'], $invoiceInformations['invoiceId'], $dateString, $invoiceInformations['seller']);

    $pdfMetadata = array(
        'author' => $invoiceInformations['seller'],
        'keywords' => sprintf('%s, FacturX/ZUGFeRD', $invoiceInformations['docTypeName']),
        'title' => $title,
        'subject' => $subject,
        'createdDate' => $invoiceInformations['date'],
        'modifiedDate' => date('Y-m-d\TH:i:s') . '+00:00',
    );

    return $pdfMetadata;
}

Expected Behavior

Allow setting a custom title like this:

return (new ZugferdDocumentPdfMerger($xml, $pdfContent))
  ->generateDocument()
  ->setTitle('Invoice 3') // Custom title
  ->downloadString('doc.pdf');

Alternatively, allow using a customizable format:

$title = sprintf('%1$s : %2$s %3$s', 
    $invoiceInformations['seller'], 
    $invoiceInformations['docTypeName'], 
    $invoiceInformations['invoiceId']);
$subject = sprintf('FacturX/ZUGFeRD %2$s %3$s dated %1$s issued by %4$s', 
    $dateString, 
    $invoiceInformations['docTypeName'], 
    $invoiceInformations['invoiceId'], 
    $invoiceInformations['seller']);

return (new ZugferdDocumentPdfMerger($xml, $pdfContent))
  ->generateDocument()
  ->setTitle('Rechnung : %2$s %3$s') // Customizable format
  ->downloadString('doc.pdf');

Context

Inside ZugferdDocumentPdfBuilderAbstract, the title and metadata are collected in preparePdfMetadata. The goal is to allow these values to be overridden without modifying core functionality.

Screenshots

Current implementation:

After attempting to add setTitle:

[horstoeko]

Hi @MarkusJLechner,

I hope you have a nice day too. I have planned the feature for next year. Thank you for the detailed specification.

Kind regards

[jusefjames]

Hi @horstoeko,
maybe to add:
I already used FPDF a long time ago to create PDF files. As I am now just adding the lines needed to create the xml file, i already have a PDF "String" where I set the metadata like title, author, creator like that:

$pdf = new PDF_MC_Table(); //PDF_MC_Table extends FPDF 
$pdf->SetTitle('Title', true);
$pdf->SetAuthor('Author', true);
$pdf->SetCreator('Creator', true);

after doing this:

$pdfContent = $pdf->Output('', 'S');
$pdfBuilder = new ZugferdDocumentPdfBuilder($xmlContent, $pdfContent);
$pdfBuilder->generateDocument()->saveDocument($filename);

The document does no more contain any metadata. Not sure if this is related to this topic or if I do something wrong.

Thanks & Best regards

[horstoeko]

Hi @MarkusJLechner,

I have created a PR #212

I've implemented the following:

• Templating (setAuthorTemplate, setTitleTemplate, setSubjectTemplate)
• A callback function to set the PDF metadata (author, subject, title)

The templates have four placeholders:

• %1$s - Invoice No.
• %2$s - Document Type
• %3$s - Seller Name
• %4$s - Invoice Date

The callback function takes the following parameters

• $which - One of "title", "subject", "author"
• $xmlContent - The content of the Invoice XML
• $invoiceInformation - The content of the relevant XML-tags
• $default - The default value (issued by the library)

The callback function has a higher priority than the templates.

I would ask you to review the pull request and give me feedback as soon as possible

Kind regards

[MarkusJLechner]

looks good to me!

[horstoeko]

Hi @MarkusJLechner,

OK. Then I'll merge the PR and create a new release later today.

Thank you very much. And have a nice day.