An ES6 module wrapper of zxing-wasm-build. Read or write barcodes in your browser!
git clone https://github.com/Sec-ant/zxing-wasm
cd zxing-wasm
npm i
npm run fetch
npm run build
npm i @sec-ant/zxing-wasm
This package exports 3 subpaths: full, reader and writer. You can choose whichever fits your needs. However, bear in mind that subpath imports needs a moduleResolution
of node16
or nodenext
in your tsconfig.json
file.
These imports includes functions to both read and write barcodes. The wasm binary size is ~1.25 MB.
import {
readBarcodeFromImageFile,
readBarcodeFromImageData,
writeBarcodeToImageFile,
} from "@sec-ant/zxing-wasm";
or
import {
readBarcodeFromImageFile,
readBarcodeFromImageData,
writeBarcodeToImageFile,
} from "@sec-ant/zxing-wasm/full";
This subpath only includes functions to read barcodes. The wasm binary size is ~948 KB.
import {
readBarcodeFromImageFile,
readBarcodeFromImageData,
} from "@sec-ant/zxing-wasm/reader";
This subpath only includes functions to write barcodes. The wasm binary size is ~392 KB.
import { writeBarcodeToImageFile } from "@sec-ant/zxing-wasm/writer";
These are 2 functions to read barcodes.
readBarcodeFromImageFile
accepts an image Blob
or an image File
as the first input. They're encoded images, e.g. .png
.jpg
files.
readBarcodeFromImageData
accepts an ImageData
as the first input. They're raw pixels that usually acquired from <canvas>
or related APIs.
Both of these 2 functions accepts the same second input: ZXingReadOptions
:
interface ZXingReadOptions {
/* Try better to find barcodes, default = true */
tryHarder?: boolean;
/* An array of barcode formats to detect, default = [] (indicates any format) */
formats?: readonly ZXingReadInputBarcodeFormat[];
/* Upper limit of the number of barcodes to be detected, default = Infinite */
maxNumberOfSymbols?: number;
}
The allowed barcode formats to read are:
type ZXingReadInputBarcodeFormat =
| "Aztec"
| "Codabar"
| "Code128"
| "Code39"
| "Code93"
| "DataBar"
| "DataBarExpanded"
| "DataMatrix"
| "EAN-13"
| "EAN-8"
| "ITF"
| "Linear-Codes"
| "Matrix-Codes"
| "MaxiCode"
| "MicroQRCode"
| "PDF417"
| "QRCode"
| "UPC-A"
| "UPC-E";
The return result of these 2 functions is a Promise
of an array of ZXingReadOutput
:
interface ZXingReadOutput {
/* detected barcode format */
format: ZXingReadOutputBarcodeFormat;
/* detected barcode text */
text: string;
/* error message (if any) */
error: string;
/* error correction code level: L M Q H */
eccLevel: ZXingReadOutputECCLevel;
/* QRCode / DataMatrix / Aztec version or size */
version: string;
/* orientation of barcode in degree */
orientation: number;
/* is the symbol mirrored (currently only supported by QRCode and DataMatrix) */
isMirrored: boolean;
/* is the symbol inverted / has reveresed reflectance */
isInverted: boolean;
/* detected barcode position:
{
bottomLeft: { x, y },
bottomRight: { x, y },
topLeft: { x, y },
topLeft: { x, y }
}
*/
position: ZXingPosition;
}
e.g.
import {
readBarcodeFromImageFile,
readBarcodeFromImageData,
ZXingReadOptions,
} from "@sec-ant/zxing-wasm/reader";
const zxingReadOptions: ZXingReadOptions = {
tryHarder: true,
formats: ["QRCode"],
maxNumberOfSymbols: 1,
};
/**
* Read from image file/blob
*/
const imageFile = await fetch(
"https://api.qrserver.com/v1/create-qr-code/?size=150x150&data=Hello%20world!"
).then((resp) => resp.blob());
const imageFileReadOutputs = await readBarcodeFromImageFile(
imageFile,
zxingReadOptions
);
console.log(imageFileReadOutputs[0].text); // Hello world!
/**
* Read from image data
*/
const imageData = await createImageBitmap(imageFile).then((imageBitmap) => {
const { width, height } = imageBitmap;
const context = new OffscreenCanvas(width, height).getContext(
"2d"
) as OffscreenCanvasRenderingContext2D;
context.drawImage(imageBitmap, 0, 0, width, height);
return context.getImageData(0, 0, width, height);
});
const imageDataReadOutputs = await readBarcodeFromImageData(
imageData,
zxingReadOptions
);
console.log(imageDataReadOutputs[0].text); // Hello world!
There is currently only 1 function to write barcodes. The first argument of this function is a text string to be encoded and the second argument is a ZXingWriteOptions
:
interface ZXingWriteOptions {
/* barcode format to write
"DataBar", "DataBarExpanded", "MaxiCode" and "MicroQRCode" are currently not supported
default = "QRCode" */
format?: ZXingWriteInputBarcodeFormat;
/* encoding charset, default = "UTF-8" */
charset?: ZXingCharacterSet;
/* barcode margin, default = 10 */
quietZone?: number;
/* barcode width, default = 200 */
width?: number;
/* barcode height, default = 200 */
height?: number;
/* (E)rror (C)orrection (C)apability level, -1 ~ 8, default = -1 (default) */
eccLevel?: ZXingWriteInputECCLevel;
}
The return result of this function is a Promise
of ZXingWriteOutput
:
interface ZXingWriteOutput {
/* a png image blob, or null */
image: Blob | null;
/* the error reason if image is null */
error: string;
}
e.g.
import { writeBarcodeToImageFile } from "@sec-ant/zxing-wasm/writer";
const writeOutput = await writeBarcodeToImageFile("Hello world!", {
format: "QRCode",
charset: "UTF-8",
quietZone: 5,
width: 150,
height: 150,
eccLevel: 2,
});
console.log(writeOutput.image);
When using this package, the wasm binary needs to be served along with the JS glue code. In order to provide a smooth dev experience, the wasm binary serve path is automatically assigned the jsDelivr CDN url upon build.
If you would like to change the serve path (to one of your local network hosts or other CDNs), please use setZXingModuleOverrides
to override the locateFile
function in advance. locateFile
is one of the Emscripten Module
attribute hooks that can affect the code execution of the Module
object during its lifecycles.
import {
setZXingModuleOverrides,
writeBarcodeToImageFile,
} from "@sec-ant/zxing-wasm";
// override the locateFile function
setZXingModuleOverrides({
locateFile: (path, prefix) => {
if (path.endsWith(".wasm")) {
return `https://esm.sh/@sec-ant/zxing-wasm/dist/full/${path}`;
}
return prefix + path;
},
});
// call read or write functions afterwards
const writeOutput = await writeBarcodeToImageFile("Hello world!");
The wasm binary won't be fetched or instantiated unless a read or write function is firstly called, and will only be instantiated once given the same module overrides. So there'll be a cold start in the first function call (or several calls if they appear in a very short period). If you want to manually trigger the download and instantiation of the wasm binary prior to any read or write functions, you can use getZXingModule
. This function will also return a Promise
that resolves to a ZXingModule
, the wasm Module
object this wrapper library is built upon.
import { getZXingModule } from "@sec-ant/zxing-wasm";
/**
* This function will trigger the download and
* instantiation of the wasm binary immediately
*/
const zxingModulePromise1 = getZXingModule();
const zxingModulePromise2 = getZXingModule();
console.log(zxingModulePromise1 === zxingModulePromise2); // true
getZXingModule
can also optionally accept a ZXingModuleOverrides
argument.
import { getZXingModule } from "@sec-ant/zxing-wasm";
getZXingModule({
locateFile: (path, prefix) => {
if (path.endsWith(".wasm")) {
return `https://esm.sh/@sec-ant/zxing-wasm/dist/full/${path}`;
}
return prefix + path;
},
});
MIT