Config module

Simple module for logging. It is a standalone piece of code that does not require any other node modules.

Installation

In your project folder run:

npm install --save node-logger-tool

Note: The module code uses few ES6 features, so at least 4.4.5 version of Node is required.

Usage

First you need to include the module and configure it.

> const loggerFactory = require('node-logger-tool').create;
> const LoggerMode = require('node-logger-tool').LoggerMode;
>
> const logger = loggerFactory(LoggerMode.Console);

Requiring the module and using a create function that can be called with an argument to set logger output. If the factory parameter is ommited, it defaults to console. Sometimes it comes handy to log events in process.stdout or process.stderr rather than in console (see example). In that case, use LoggerMode.Stdio as an argument for factory function.

Using the logger module is quite straightforward:

logger.log('hello'); // outputs info: hello

logger.log(42, 'the number'); // outputs the number: 42 (providing the label for logged data)

logger.info('informed'); // same as logger.log()

logger.error(new Error('everything is lost')); // outputs error: everything is lost

If the non-primitive value like Array or Object is passed to the logger, it is JSON-encoded for better readability.

Logging to file requires more configuration (passing additional parameter to the loggerFactory function or setMode method).

const logger = loggerFactory(LoggerMode.File, 'path/to/folder');

logger.setMode(LoggerMode.File, 'path/to/folder');

Example

// parent.js
const log = require('node-logger-tool').create();   // defaults to console 
const spawn = require('child_process').spawn;
const child = spawn('node', ['child.js']);

child.stdout.on('data', (status) => {
    log.info('child process status: ' + status);
});

// child.js
const LoggerMode = require('node-logger-tool').LoggerMode; 
const logger = require('node-logger-tool').create(LoggerMode.Stdio)';
const notify = logger.info.bind(logger);

// do some heavy lifting...

// notify the parent process
notify('work done');

Issues

Since the GitHub repository is not ready yet, please use my email address in profile to contact me. Cheers!