ReceiptLine for Dart #

A pure-Dart implementation of the ReceiptLine receipt description language. It can render the same document as plain text or SVG, or generate ESC/POS bytes for a thermal printer. The package has no Flutter SDK dependency and works in Dart and Flutter applications, including Flutter web.

Features #

• ReceiptLine columns, magnetic alignment, wrapping, fixed/variable widths, rules, cuts, text decoration, embedded PNGs, raw commands, barcodes, and QR codes
• SVG output for Flutter previews and digital receipts
• Plain-text output for logs, tests, and accessible fallbacks
• Uint8List ESC/POS output with PNG rasterization and native barcode/QR commands
• CP437/852/858/860/863/865/866/1252, Shift-JIS, GBK, Korean, and Thai encoding
• A Dart StreamTransformer for chunked input

Install #

Until the package is published, reference this checkout from your app:

dependencies:
  receiptline:
    path: ../receiptline

Then run dart pub get or flutter pub get.

Render SVG #

import 'package:receiptline_dart/receiptline_dart.dart';

const document = '''
{align:center}
^^MY STORE
{align:left}
Coffee | 3.50
Cake | 4.25
---
^TOTAL | ^7.75
{option:qrcode,m,4}
{code:https://example.com/receipt/42}
''';

final svg = ReceiptLine.transform(
  document,
  const ReceiptLineOptions(cpl: 42),
);

In Flutter, render the returned string with flutter_svg:

SvgPicture.string(svg, fit: BoxFit.contain)

Generate printer bytes #

final bytes = ReceiptLine.transformBytes(
  document,
  const ReceiptLineOptions(
    cpl: 42,
    encoding: ReceiptLineEncoding.cp437,
    command: ReceiptLineCommand.escPos,
    cutting: true,
  ),
);

// Send bytes to the Bluetooth, USB, TCP, or platform printer API you use.
await printer.write(bytes);

Printer output is deliberately byte-oriented. This avoids the lossy "binary string" convention used by JavaScript printer libraries.

Other APIs #

final text = transform(
  document,
  const ReceiptLineOptions(command: ReceiptLineCommand.text),
);

final barcode = generateBarcode(
  const ReceiptBarcode(data: '201234567890', type: 'ean', hri: true),
);

final qrMatrix = generateQrCode(
  const ReceiptQrCode(data: 'hello', level: 'm', quietZone: true),
);

final output = await Stream.fromIterable(['Coffee | ', '3.50'])
    .transform(ReceiptLine.createTransformer())
    .single;

Compatibility #

The parser and text layout are ported from ReceiptLine 4.0.2. All official English and Japanese example documents have been compared with the upstream implementation; plain-text output is identical, and SVG dimensions match across the official English suite.

The current binary backend targets standard thermal ESC/POS. Upstream's specialized Epson, SII, Citizen, Fujitsu, impact, StarPRNT, Star Line, and Star Graphic dialects are not yet implemented. multilingual ESC/POS currently uses CP437, and CP950/Big5 printer-byte conversion falls back to CP437; SVG and text layout still support their wide-character measurement. The backend interface is separated from the parser so additional printer dialects can be added without changing ReceiptLine layout logic.

SVG output is semantically compatible rather than byte-identical: it uses a stable filter identifier and simplified vector junctions for ruled tables.

License #

Apache-2.0. This is a derivative port of ReceiptLine and retains its attribution in NOTICE. QR Code is a registered trademark of DENSO WAVE INCORPORATED.