module::Logger

Class to log data consistently which supports colorful formatting, verbosity control, chaining, combining several loggers/consoles into logging network. Logger provides 10 levels of verbosity [ 0,9 ] any value beyond clamped and multiple approaches to control verbosity. Logger may use console/stream/process/file as input or output. Unlike alternatives, colorful formatting is cross-platform and works similarly in the browser and on the server side. Use the module to make your diagnostic code working on any platform you work with and to been able to redirect your output to/from any destination/source.

The module in JavaScript provides convenient, layered, cross-platform means for multilevel, colorful logging. Logger writes messages( incoming & outgoing ) to the specified output. By default it prints messages using console as output. Supports colorful output in browser and shell, multilevel output, chaining with other console-like objects to perform message transfering between multiple inputs/outputs.

Try out from the repository

git clone https://github.com/Wandalen/wLogger
cd wLogger
will .npm.install
node sample/trivial/Sample.s

Make sure you have utility willbe installed. To install willbe: npm i -g willbe@stable. Willbe is required to build of the module.

To add to your project

npm add 'wLogger@stable'

Willbe is not required to use the module in your project as submodule.

Usage

Options

• output { object }[ optional, default : console ] - single output object for current logger.
• level { number }[ optional, default : 0 ] - controls current output level.

Methods

Output:

• log
• error
• info
• warn

Leveling:

• Increase current output level - up
• Decrease current output level - down

Chaining:

• Add object to output list - outputTo
• Remove object from output list - outputUnchain
• Add current logger to target's output list - inputFrom
• Remove current logger from target's output list - inputUnchain

Other:

• Check if object exists in logger's inputs list - hasInput
• Check if object exists in logger's outputs list - hasOutput

Example #1

/* Simple output */
var l = new wLogger();
l.log( 'abc' );
/* Output to default logger */
logger.log( 'efg' );

Example #2

/* Leveling */
var l = new wLogger();
l.log('0 level')
/* Increase current level by 2 */
l.up( 2 );
l.log('2 level')
/*
0 level
    2 level
*/

Example #3

/* Chaining */
/* Disabling default output for l1 */
var l1 = new wLogger({ output : null });
var l2 = new wLogger();
/* Setting prefix for second logger */
l2._prefix = 'l2_'
/* Setting second logger as output */
l1.outputTo( l2 );
/* Each message from l1 will be transfered to l2 */
l1.log('message1')
l1.log('message2')
/*
l2_message1
l2_message2
*/

Example #4

/* Manual colorful logging */
var l = new wLogger();
/* prints message with red color,then sets foreground color to default */
l.log( '#foreground : red#text here#foreground : default#' );
/* prints message on yellow background,then sets background color to default */
l.log( '#background : yellow#text here#background : default#' );

Example #5

/* Colorful logging using shortcut wTools.strColor */
let _ = wTools;
var l = new wLogger();
/* prints message with red color */
l.log( _.strColor.fg( 'message','red' ) );
/* prints message with yellow background */
l.log( _.strColor.bg( 'message','yellow' ) );

Example #6

/*  By default logger cant use console as input & output device in one time, by using consoleBar we can
get all console output and print it through outputLogger without recursion.
See ConsoleBar sample for details.
*/

var outputLogger = new wLogger();
wLogger.consoleBar
({
  outputLogger : outputLogger,
  bar : 1
});

console.log( 'Message from console' );