@goodboy008/labelize-wasm

The Labelize ZPL/EPL label engine compiled to WebAssembly. Parse and render ZPL/EPL label data to PNG (or PDF) entirely in the browser, Node.js, or your bundler — no server needed.

Usage

Bundlers (webpack 5, Vite with vite-plugin-wasm)

import { lz_render } from "@goodboy008/labelize-wasm";

const zpl = new TextEncoder().encode("^XA^FO50,50^A0N,40,40^FDHELLO WORLD^FS^XZ");
const png = lz_render(zpl, 102.0, 152.0, 8, false, false, false);
// png is a Uint8Array — pass it to an <img> via URL.createObjectURL

The package is the standard wasm-bindgen bundler output: labelize_wasm.js initializes the engine at module top level and exports lz_render / lz_playground_html.

Node.js (≥ 20)

import { lz_render } from "@goodboy008/labelize-wasm/init";

const zpl = Buffer.from("^XA^FO50,50^A0N,40,40^FDHELLO WORLD^FS^XZ", "ascii");
const png = lz_render(zpl, 102.0, 152.0, 8, false, false, false);

The /init subpath instantiates the engine from the packaged .wasm directly, without bundler support or Node flags.

API

lz_render(src, width_mm, height_mm, dpmm, antialias, want_pdf, is_epl) -> Uint8Array

| param | meaning | |---|---| | src | raw label bytes (ZPL, or EPL when is_epl = true) | | width_mm / height_mm | label canvas size in millimetres (defaults: 102 × 152) | | dpmm | dots per millimetre (default 8) | | antialias | keep renderer greys instead of thresholding to 1-bit | | want_pdf | return a PDF instead of PNG | | is_epl | parse input as EPL instead of ZPL |

Errors throw a string prefixed with the failure stage: 1: parse error, 2: rendering error.

lz_playground_html() -> string returns the Labelize playground page (identical to the HTTP server's /).

Release assets

GitHub releases also attach labelize-wasm-wasm32.zip with the raw glue + .wasm files, for direct use without npm. See workers/build.sh to rebuild the engine:

cd workers && ./build.sh   # requires Rust wasm32 target + wasm-bindgen-cli

License

MIT AND BSD-3-Clause