CONTRIBUTING.md

Getting Started

We would ❤️ to have pull requests for you. So here is how you start development with JsBarcode.

First fork and clone the repo:

git clone git@github.com:your-username/JsBarcode.git

Then run npm install to set everything up. Make sure you have all dependencies of node-canvas installed before doing this, or check Using Docker section.

You are now ready to start doing your changes.

JsBarcode is using gulp in the building step. Here comes some commands that will come handy when developing.

gulp compile # Compile the code (for nodejs)
gulp compile-web # Compiles down to JsBarcode.all.js
gulp compress # Compiles and compresses all individual barcode files

gulp watch # Listens to file changes and re-compiles automatically
gulp watch-web # Listens to file changes and re-compiles to JsBarcode.all.js automatically

gulp lint # Checking the code according to the code style specified in .eslintrc

Testing

JsBarcode has tests on all barcode symbologies (and more). If you want to test your changes just run npm test and the code will be compiled and tested.

There are also visual tests located under test/browser/.

Using Docker

If you have installed Docker, you can avoid local installation of dependencies for node-canvas. For doing that, run npm install --ignore-scripts instead of npm install. Then you can run tests by docker-compose up

Symbologies and The Core

JsBarcode is divided up in two distinct parts. The barcode symbologies (EAN-13, CODE128, ITF, ...) and the core.

Symbologies

Implementing a new symbology is the easiest way to contribute. Just follow the standard for that symbology and create a class that generate the correct binary data.

The structure of such a class is as follows:

import Barcode from "../Barcode.js";

class GenericBarcode extends Barcode{
	constructor(data, options){
		super(data, options); // Sets this.data and this.text
	}

	// Return the corresponding binary numbers for the data provided
	encode(){
		return {
			data: "10101010101010101010101010101010101010101",
			text: this.text
		};
	}

	// Resturn true/false if the string provided is valid for this encoder
	valid(){
		return true;
	}
}

It might be a good idea to check one of the already implemented barcodes (such as ITF14) for inspiration.

The Core / Renderers

The core part handles the API requests and calls the renderers. If you want to do any structural changes please create an issue or ask about it in the gitter chat first.

Bug fixes is of course welcome at any time 👍

Pull Requests

So you are ready to make a PR? Great! 😄

But first make sure you have checked some things.

• Your code should follow the code style guide provided by .eslintrc by running gulp lint
• If you implemented a new symbology, make sure you have tests for it
• Don't commit build changes. No dist/ or bin/ changes in the PR.