Qrcode Laravel Package

Getting Started

This package provides a simple, lightweight QR code generator that supports multiple output formats — PNG, HTML, and direct embedding into PDFs via mPDF. To begin, install it via Composer:

composer require mpdf/qrcode

The library is PSR-4 autoloaded — no additional bootstrap needed. The primary entry point is the QrCode class (from the Mpdf\QrCode namespace). A minimal usage example:

use Mpdf\QrCode\QrCode;
use Mpdf\QrCode\Output;

$qr = new QrCode('https://example.com');
$png = (new Output\Png())->output($qr, ['size' => 200]);
file_put_contents('qrcode.png', $png);

For immediate visual feedback in a web context, use Output\Html() to embed the QR code inline. For PDF reports or invoices, integrate directly with mPDF using Output\Mpdf() — see the “Implementation Patterns” section.

Implementation Patterns

• PDF Workflow (mPDF): When generating PDFs with mPDF, inject the QR code using Mpdf\Output\Mpdf::output($qr, $mpdf) — this returns an mPDF-compatible HTML fragment (e.g., <img src="data:image/png;base64,...">) safe to embed in WriteHTML().
• Responsive Web Embedding: Use Output\Html() with CSS to control display size (e.g., width: 100%; max-width: 200px). Avoid <canvas> — this library outputs base64-encoded PNG.
• Batch Generation: For generating many QR codes (e.g., ticketing), preconfigure the QR instance once and reuse it — the generator caches internal data structures.
• Form Integration: Pair with form submissions (e.g., RSVP or checkout confirmation) by encoding structured data:

  $qr = new QrCode(json_encode(['order_id' => $id, 'user' => $userId]));
  

• Caching Strategy: Since QR codes are static, cache generated PNG/HTML output using Laravel’s cache system keyed by content hash to avoid redundant generation on repeat requests.

Gotchas and Tips

• Error Correction Level Matters: By default, uses QrCode::ERROR_CORRECT_L. For printed materials (labels, tickets), consider M, Q, or H for robustness — e.g., $qr->setEccLevel(QrCode::ERROR_CORRECT_M);.
• mPDF Output Specifics: Output\Mpdf() returns a string of HTML, not a resource or image object. Do not wrap it in <img> tags — it’s already embedded.
• Data Size Limits: QR codes become unreadable if the payload is too large. For long payloads (e.g., full JSON), truncate or hash first — 2,000+ characters often exceeds practical scannability.
• Debugging Quiet Zones: Ensure sufficient whitespace padding (->setMargin(10)) — many mobile scanners fail without it.
• No Built-in Color Customization: PNG output is black-on-white only. For colored QR codes (e.g., brand-aligned), override Output\Png and modify internal GD resources — note this may break mPDF compatibility.
• mPDF Compatibility: Ensure mPDF/mpdf is installed after this package — mPDF uses its own QR code support in newer versions, and conflicts can occur if both libraries attempt to define QrCode. Check version compatibility.