@hopla/labels

Shared label-PDF core for PhoneTest and SheetCompare — a CODE128 barcode encoder + a pdf-lib product-label generator. Pure and Cloudflare-Workers-safe (no fs, no Buffer, no node:*, no DOM), so the same code runs in the Electron main process and inside a CF Worker.

Install

npm i @hopla/labels

Peer dependencies

pdf-lib and @pdf-lib/fontkit are peer dependencies — install them in the consuming project (both apps already pin these):

npm i pdf-lib@^1.17.1 @pdf-lib/fontkit@^1.1.1

Cloudflare Workers

Workers consumers must enable nodejs_compat (fontkit's font registration needs it):

// wrangler.jsonc
{ "compatibility_flags": ["nodejs_compat"] }

Usage

import { generateLabelsPdf, type ProductLabelData } from '@hopla/labels';

const labels: ProductLabelData[] = [/* one per device */];

// BRING YOUR OWN FONT — see "Fonts" below.
const pdfBytes: Uint8Array = await generateLabelsPdf(labels, {
  fontBytes: mySfProTextRegularTtf, // Uint8Array
});

generateLabelsPdf returns a Uint8Array (drop it straight into new Response(pdfBytes) in a Worker, or write it to disk in Electron). Each ProductLabelData renders one 50.8mm × 101.6mm (144pt × 288pt) page.

Barcode primitives

import { drawBarcode, encode, BAR_WIDTH_REDUCTION } from '@hopla/labels';

drawBarcode renders a CODE128 barcode onto a pdf-lib page. Numeric payloads (IMEIs) use CODE128C (denser, scans reliably on 203 dpi thermal printers); non-numeric payloads fall back to CODE128B. A small Bar Width Reduction (BAR_WIDTH_REDUCTION, in pt) compensates thermal ink spread.

Fonts (bring-your-own)

The package does not bundle a body font. The label's legacy look uses Apple's SF Pro Text, which is Apple-licensed — redistributing the font file as a standalone npm artifact is restricted. So the font is injected: each app ships its own copy and passes the TrueType bytes via opts.fontBytes. The logo and status icons (own art) are bundled.

License

MIT © Phones.Trade