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LibreDTE Core provides powerful PDF generation capabilities for electronic tax documents, creating printable versions with the electronic stamp (TED) and all required information.

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Overview

The RendererWorker handles PDF generation using customizable templates. It supports:
  • Standard and custom templates
  • Multiple PDF engines (mPDF, TCPDF)
  • TED barcode/QR code rendering
  • Company logos and branding
  • Detailed item listings
  • Tax calculations and totals

​
Basic PDF Generation

Generate a PDF from a document: 
$documentComponent = $app->getPackage('billing')
    ->getComponent('document');

// Create document
$bag = $documentComponent->bill($data, $caf, $certificate);

// Generate PDF
$rendererWorker = $documentComponent->getRendererWorker();
$pdfContent = $rendererWorker->render($bag);

// Save to file
file_put_contents('/path/to/invoice.pdf', $pdfContent);

// Or output to browser
header('Content-Type: application/pdf');
header('Content-Disposition: inline; filename="invoice.pdf"');
echo $pdfContent;

​
Renderer Configuration

The renderer uses a strategy pattern with configurable options: 
// RendererWorker.php:58-64
protected array $optionsSchema = [
    '__allowUndefinedKeys' => true,
    'strategy' => [
        'types' => 'string',
        'default' => 'template.estandar',  // Default template
    ],
];

​
Available Options

​
strategy
string
default:"template.estandar"
The rendering strategy to use. Default is the standard LibreDTE template.
​
template
string
default:"estandar"
Template name within the strategy.
​
format
string
default:"pdf"
Output format (typically ‘pdf’).

​
PDF Rendering Process

The rendering process follows these steps:
1

Normalize Document Data

The document is fully normalized to ensure all required data is present.
// RendererWorker.php:88
$bag = $this->documentBagManager->normalize($bag, all: true);
2

Select Template Strategy

The appropriate rendering strategy is selected based on options.
// RendererWorker.php:84
$strategy = $this->getStrategy($options->get('strategy'));
3

Render to PDF

The strategy renders the document using the configured template.
// RendererWorker.php:91
$renderedData = $strategy->render($bag);
4

Return Binary Content

The PDF binary content is returned as a string.

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Working with Templates

The standard template (template.estandar) provides a professional layout: 
// Use standard template
$options = [
    'renderer' => [
        'strategy' => 'template.estandar',
        'template' => 'estandar',
        'format' => 'pdf',
    ],
];

$bag = $documentComponent->bill($data, $caf, $certificate, $options);
$pdf = $rendererWorker->render($bag);

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Template Features

The standard template includes:

Header Section

  • Company logo
  • Company information (RUT, name, address)
  • Document type and number
  • Issue date

Recipient Details

  • Recipient RUT and name
  • Address and location
  • Business activity

Item Details

  • Product/service descriptions
  • Quantities and units
  • Unit prices
  • Line totals

Totals & TED

  • Subtotals and taxes
  • Discounts and surcharges
  • Final total
  • TED barcode (electronic stamp)

​
Adding Custom Data

Include additional data in PDFs using the LibreDTE data structure: 
$bag = new DocumentBag(
    inputData: $documentData,
    libredteData: [
        'extra' => [
            'logo' => '/path/to/company-logo.png',
            'footer_text' => 'Thank you for your business!',
            'payment_instructions' => 'Bank transfer to account 123456',
            'terms' => 'Net 30 days',
        ],
    ],
    caf: $caf,
    certificate: $certificate,
    options: [
        'renderer' => [
            'template' => 'estandar',
        ],
    ]
);

$pdf = $rendererWorker->render($bag);

​
PDF Engines

LibreDTE Core supports multiple PDF generation engines:
mPDF is the default engine, providing excellent Unicode support and advanced features.
// composer.json:49
"mpdf/mpdf": "^8.2"
Features:
  • Full UTF-8 support
  • Custom fonts
  • Header/footer templates
  • Watermarks
  • Better performance for complex layouts

​
Generate PDF for Multiple Documents

Create PDFs for a batch of documents: 
$documents = [$data1, $data2, $data3];
$pdfFiles = [];

foreach ($documents as $index => $data) {
    try {
        // Create document
        $bag = $documentComponent->bill($data, $caf, $certificate);
        
        // Generate PDF
        $pdf = $rendererWorker->render($bag);
        
        // Save with folio number in filename
        $folio = $bag->getFolio();
        $filename = "invoice_{$folio}.pdf";
        $filepath = "/path/to/pdfs/{$filename}";
        
        file_put_contents($filepath, $pdf);
        $pdfFiles[] = $filepath;
        
        echo "Generated: {$filename}\n";
        
    } catch (\Exception $e) {
        echo "Error generating PDF for document {$index}: {$e->getMessage()}\n";
    }
}

echo "Generated " . count($pdfFiles) . " PDFs\n";

​
Rendering HTML Preview

While the default format is PDF, you can potentially render to HTML for preview: 
$options = [
    'renderer' => [
        'format' => 'html',  // If supported by strategy
    ],
];

$bag = $documentComponent->bill($data, $caf, $certificate, $options);

try {
    $htmlContent = $rendererWorker->render($bag);
    echo $htmlContent;
} catch (\Exception $e) {
    echo "HTML rendering not supported by this strategy";
}
HTML rendering support depends on the specific template strategy implementation. The standard template focuses on PDF output.

​
Complete Example: Invoice to PDF

Full workflow from data to PDF: 
use libredte\lib\Core\Package\Billing\Component\Document\DocumentComponent;

// 1. Prepare invoice data
$invoiceData = [
    'Encabezado' => [
        'IdDoc' => [
            'TipoDTE' => 33,
            'Folio' => 150,
            'FchEmis' => date('Y-m-d'),
        ],
        'Emisor' => [
            'RUTEmisor' => '12345678-5',
            'RznSoc' => 'Mi Empresa S.A.',
            'GiroEmis' => 'Servicios de TI',
            'Acteco' => 620200,
            'DirOrigen' => 'Av. Apoquindo 3000',
            'CmnaOrigen' => 'Las Condes',
        ],
        'Receptor' => [
            'RUTRecep' => '87654321-9',
            'RznSocRecep' => 'Cliente SpA',
            'GiroRecep' => 'Comercio',
            'DirRecep' => 'Calle Principal 100',
            'CmnaRecep' => 'Santiago',
        ],
    ],
    'Detalle' => [
        [
            'NmbItem' => 'Consultoría desarrollo software',
            'QtyItem' => 40,
            'UnmdItem' => 'horas',
            'PrcItem' => 50000,
        ],
        [
            'NmbItem' => 'Hosting mensual',
            'QtyItem' => 1,
            'UnmdItem' => 'mes',
            'PrcItem' => 100000,
        ],
    ],
];

// 2. Additional PDF data
$libredteData = [
    'extra' => [
        'logo' => '/var/www/assets/logo.png',
        'payment_info' => [
            'bank' => 'Banco de Chile',
            'account' => '1234567890',
            'account_type' => 'Cuenta Corriente',
        ],
        'notes' => 'Pago neto 30 días',
    ],
];

// 3. Create document
$bag = new DocumentBag(
    inputData: $invoiceData,
    libredteData: $libredteData,
    caf: $caf,
    certificate: $certificate,
    options: [
        'renderer' => [
            'template' => 'estandar',
        ],
    ]
);

// 4. Build document
$documentComponent = $app->getPackage('billing')->getComponent('document');
$parserWorker = $documentComponent->getParserWorker();
$builderWorker = $documentComponent->getBuilderWorker();

$parserWorker->parse($bag);
$document = $builderWorker->build($bag);

// 5. Generate PDF
$rendererWorker = $documentComponent->getRendererWorker();

try {
    $pdfContent = $rendererWorker->render($bag);
    
    // 6. Save PDF
    $filename = "factura_{$bag->getFolio()}.pdf";
    file_put_contents("/var/invoices/{$filename}", $pdfContent);
    
    echo "PDF generated: {$filename}\n";
    echo "Size: " . strlen($pdfContent) . " bytes\n";
    
    // 7. Optional: Email PDF to customer
    // sendEmailWithAttachment($customer->email, $filename, $pdfContent);
    
} catch (\Exception $e) {
    echo "Error generating PDF: " . $e->getMessage();
}

​
Troubleshooting

Check that PDF engine dependencies are installed:
composer require mpdf/mpdf
composer require tecnickcom/tcpdf
Verify PHP extensions:
php -m | grep -E 'gd|mbstring'
Ensure the document has a valid electronic stamp:
if (!$bag->getTimbre()) {
    echo "Document missing TED stamp";
}

// Check TED content
$ted = $document->getTED();
if (empty($ted)) {
    echo "TED is empty - was CAF provided?";
}
Verify logo path is accessible and format is supported:
$logoPath = '/path/to/logo.png';

if (!file_exists($logoPath)) {
    echo "Logo file not found";
}

// Supported formats: PNG, JPG, GIF
$libredteData = [
    'extra' => [
        'logo' => $logoPath,
    ],
];
Increase PHP memory limit for complex PDFs:
ini_set('memory_limit', '256M');

// Or in php.ini:
// memory_limit = 256M

​
Performance Tips

Cache rendered PDFs: Store generated PDFs to avoid regenerating them for the same document.
$cacheKey = "pdf_invoice_{$bag->getFolio()}";

if ($cache->has($cacheKey)) {
    $pdf = $cache->get($cacheKey);
} else {
    $pdf = $rendererWorker->render($bag);
    $cache->set($cacheKey, $pdf, 3600); // Cache for 1 hour
}

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Next Steps

Creating Documents

Learn how to create electronic documents

SII Integration

Send documents to SII after generating PDFs

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