Jsw-logger NPM

JSW-Logger

Javascript logging module which writes in the console all warnings and erros

Installation

npm install --save jsw-logger

Usage

Currently, JSW-Logger can be used within a TypeScript based project, as a node dependency or directly in the browser.

Declaration:

First we need to import the dependency:

Typescript

import { JSWLogger } from "jsw-logger";

Node JS

var JSWLogger = require("jsw-logger").JSWLogger;

Browser

<script src="path/to/deps/dist/jsw-logger.min.js"></script>
<!-- This exposes a global "JSWLogger" variable -->

Instantiating

We can instanciate the logger passing a bunch of options:

var Logger = JSWLogger.getInstance({
    level: 2,   // logs "info", "warn" and "error" by default
    hideAllLogs: false, // hides messsages from being logged
    hideLevelLog: false,    // hides the "LOG: " from the begining of the message
    throwError: true   // throw an error when "Logger.throw"
});

Or we can retrieve the instance with the options by default:

var Logger = JSWLogger.instance;

Also, the options can only by setted when instantiating with the first way. To change them, we should access the options object: Logger.options.throwError = false Or we can drop the instance so we can regenerate it: JSWLogger.__dropInstance()

Note that as this is a singleton (can only be instantiated once), so if you drop the instance, it will be dropped for all

Logging

The level logging hierarchy is as follows:

Name	Level	Method	Uses
Silly	6	Logger.silly	Some dummy logs, less relevants than a debug
Debug	5	Logger.debug	For debugging purposes
Verbose	4	Logger.verbose	For extended log messages
Log	3	Logger.log	The standar logging
Info	2	Logger.info	To show relevant information messages
		Logger.inform	Works as an alias for "info"
		Logger.information	Worksas an alias for "info"
Warn	1	Logger.warn	To show application warnings
		Logger.warning	Works as an alias for "warn"
Error	0	Logger.error	To output error generated by the application
		Logger.throw	Same as "error", but throws an Exception is configured to

The lower we set the level whe instanciating, the less methods will output something. Eg.:

Logger.debug("Not shown"); // -> outputs nothing, as the default is log (2)
Logger.info("Some informative message"); // -> INFO: Some informative message
// Can use interpolation
Logger.warn("Be careful %s!", "Ryan"); // -> WARN: Be careful Ryan!
Logger.error("Line %d doesn't compile", 562); // -> ERROR: Line 562 doesn't compile