floimg-qr

QR code generator for floimg using the qrcode library.

Installation

npm install @teamflojo/floimg @teamflojo/floimg-qr

Usage

import createClient from '@teamflojo/floimg';
import qr from '@teamflojo/floimg-qr';

const floimg = createClient();
floimg.registerGenerator(qr());

// Generate a QR code
const qrCode = await floimg.generate({
  generator: 'qr',
  params: {
    text: 'https://github.com/bcooke/floimg',
    width: 300,
    errorCorrectionLevel: 'H'
  }
});

// Save to filesystem or S3
const result = await floimg.save(qrCode, './output/qr-github.png');
// Or save to S3:
// const result = await floimg.save(qrCode, 's3://my-bucket/qr/github.png');
console.log(result.location);

Examples

Basic QR Code

const qr = await floimg.generate({
  generator: 'qr',
  params: {
    text: 'Hello World!',
    width: 200
  }
});

URL QR Code

const qr = await floimg.generate({
  generator: 'qr',
  params: {
    text: 'https://example.com',
    width: 300,
    errorCorrectionLevel: 'H'  // High error correction
  }
});

Custom Colors

const qr = await floimg.generate({
  generator: 'qr',
  params: {
    text: 'Styled QR Code',
    width: 400,
    color: {
      dark: '#667eea',   // Purple
      light: '#ffffff'   // White background
    }
  }
});

SVG Output

const qr = await floimg.generate({
  generator: 'qr',
  params: {
    text: 'https://example.com',
    format: 'svg',
    width: 300
  }
});

vCard Contact

const vcard = `BEGIN:VCARD
VERSION:3.0
FN:John Doe
TEL:+1-555-1234
EMAIL:[email protected]
END:VCARD`;

const qr = await floimg.generate({
  generator: 'qr',
  params: {
    text: vcard,
    width: 350,
    errorCorrectionLevel: 'H'
  }
});

WiFi Network

const wifi = 'WIFI:T:WPA;S:MyNetwork;P:MyPassword;;';

const qr = await floimg.generate({
  generator: 'qr',
  params: {
    text: wifi,
    width: 300
  }
});

Parameters

| Parameter | Type | Default | Description | |-----------|------|---------|-------------| | text | string | required | Text/URL to encode | | width | number | 300 | Output width in pixels | | errorCorrectionLevel | 'L'|'M'|'Q'|'H' | 'M' | Error correction level | | margin | number | 4 | Margin around QR code (in modules) | | color.dark | string | '#000000' | Dark color | | color.light | string | '#ffffff' | Light/background color | | format | 'png'|'svg' | 'png' | Output format | | version | number | auto | QR code version (1-40) | | maskPattern | number | auto | Mask pattern (0-7) |

Error Correction Levels

• L (Low): ~7% of codewords can be restored
• M (Medium): ~15% of codewords can be restored (default)
• Q (Quartile): ~25% of codewords can be restored
• H (High): ~30% of codewords can be restored

Higher error correction allows QR codes to be read even if partially damaged, but requires more data.

Configuration

floimg.registerGenerator(qr({
  errorCorrectionLevel: 'H',  // Default to high error correction
  width: 400,                  // Default width
  margin: 5,                   // Default margin
  color: {
    dark: '#000000',
    light: '#ffffff'
  }
}));

Use Cases

Event Tickets

const ticketData = JSON.stringify({
  event: 'Concert',
  seat: 'A12',
  code: 'ABC123'
});

const ticket = await floimg.generate({
  generator: 'qr',
  params: {
    text: ticketData,
    width: 300,
    errorCorrectionLevel: 'H'
  }
});

Payment QR Codes

const paymentUrl = 'bitcoin:1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa?amount=0.01';

const payment = await floimg.generate({
  generator: 'qr',
  params: {
    text: paymentUrl,
    width: 350,
    errorCorrectionLevel: 'H'
  }
});

App Store Links

const appStore = 'https://apps.apple.com/app/id123456789';

const qr = await floimg.generate({
  generator: 'qr',
  params: {
    text: appStore,
    width: 250,
    margin: 6
  }
});

QR Code Library Documentation

This generator uses the qrcode library directly. For advanced options:

• https://github.com/soldair/node-qrcode
• https://github.com/soldair/node-qrcode#qr-code-options

Performance

• Generation time: ~5-50ms depending on data size
• Memory: Minimal (~1-5MB)
• No external dependencies: Pure Node.js

Limitations

• Maximum data capacity depends on QR version and error correction level
• QR Version 40 with Low error correction can store ~2,953 bytes
• Higher error correction = less data capacity

License

MIT

See Also

• floimg - Core library
• qrcode - QR code library