log4js

A simple, very light-weight Logger implementation for JS (inspired by log4j)

Installation

npm i --save-dev @adazes/log4js

Usage

Importing

Node.js

import * as log4js from "@adazes/log4js";

Browsers

<script src="your/js/include/path/log4js-for-browsers.min.js" type="text/javascript"></script> <!-- 6.6KB -->

Using (both (Node.js & Browsers))

var logger = new log4js.Logger("Demo", 
	log4js.Level.WARN,  // Level.OFF can also be used to turn logging off completely
	true);
if (logger.isInfoEnabled())
	logger.info("This isn't logged since level is higher than threshold set");

var logger2 = new log4js.Logger({
	name: "Logger initialized with a config object",
	level: log4js.Level.ALL,
	useLevelAbbreviation: true});
logger2.all("This is logged");
// A> Logger initialized with a config object (2022-6-10, 14:14:30): This is logged

Config object usable during construction (with default values indicated)

{
	name: '',
	level: log4js.Level.INFO,
	skipPrefix: false,
	skipTimestamp: false,
	skipName: false,
	useLevelAbbreviation: false,
	dateFormatter: new Intl.DateTimeFormat(navigator.language+ "-u-ca-iso8601", {
		  year: 'numeric', month: 'numeric', day: 'numeric',
		  hour: 'numeric', minute: 'numeric', second: 'numeric',
		  hour12: false
	}
}

These same settings can be passed in, in this exact order, as individual constructor parameters, which frequently results in less typing. See var logger for an example in Using section above.

Demo

Feel free to take a look at the demo for live examples of logging code & messages logged in browser console.

Automated testing

git clone https://github.com/haqer1/log4js.git
cd log4js
npm install
npm run test