logdown.js

Logdown is a debug utility for the browser and the server with Markdown support. It does not have any dependencies and is only 2K gzipped.

You can see it in action in the example page or in the preview below.

Preview

Browser

Server

Installation

npm

If on the server, install it through npm:

npm install --save logdown

const Logdown = require('logdown')
const logger = logdown('foo')

Or as a more idiomatic way:

const logger = require('logdown')('foo')

Bower

In the browser you can install it through Bower:

bower install logdown

const logger = require('logdown')('foo')

Other

You can also use the lib in the browser in the same way as in the server if you use Browserify. Or you can just download it here and put the dist/logdown.js file in your public folder. Another way of retrieving Logdown is via jsDelivr, a public Open Source CDN.

Import

SystemJS

Using the dynamic module loader SystemJS, Logdown can be loaded as a CommonJS module:

SystemJS.config({
  map: {
    'logdown': 'bower_components/logdown/dist/logdown.js'
  },
  packages: {
    'logdown': {format: 'cjs'}
  }
});

System.import('logdown').then(function(Logdown) {
  const logger = Logdown('foo')
});

TypeScript

import Logdown = require('logdown')

const logger: Logdown = new Logdown('foo')

Usage

Logging

It is highly recommended to use a prefix for your instance, this way you get a nice prefixed message on console and it is possible to silence instances based on the prefix name, as we will see after.

After creating your object, you can use the regular log, warn, info and error methods as we have on console, but now with Markdown support.

logger.log('lorem *ipsum*')
logger.info('dolor _sit_ amet')
logger.warn('consectetur `adipiscing` elit')

You can pass multiple arguments

logger.log('lorem', '*ipsum*')
logger.info('dolor _sit_', 'amet')
logger.warn('consectetur', '`adipiscing` elit')

Options

The constructor accepts one object for configuration on instantiation time.

Example

const options = {alignOutput: true, prefix: 'foo'}
const logger = new Logdown(options)

The following options can be used for configuration.

`prefix`

Type: 'String'
Default: ''

const logger = logdown({ prefix: 'foo' })
logger.log('Lorem ipsum') // Will use console.log with a prefix

The above code is the same as:

const logger = logdown('foo')
logger.log('Lorem ipsum')

You should use the name of your module. You can, also, use : to separate modules inside one big module.

var fooBarLogger = Logdown('foo:bar')
fooBarLogger.log('Lorem ipsum')

var fooQuzLogger = Logdown('foo:quz')
fooQuzLogger.log('Lorem Ipsum')

`markdown`

Type: 'Boolean'
Default: true

If setted to false, markdown will not be parsed.

var logger = Logdown({markdown: false})
logger.log('Lorem *ipsum*') // Will not parse the markdown

For Markdown, the following mark-up is supported:

// Bold with "*"" between words
logger.log('lorem *ipsum*')

// Italic with "_" between words
logger.log('lorem _ipsum_')

// Code with ` (backtick) between words
logger.log('lorem `ipsum`')

`alignOutput`

Type: 'Boolean'
Default: false

If setted to true, the name of the logger instance will have the same length as the longest name of any other Logdown instance.

Enabling/disabling instances

It is possible to enable/disable the output of instances using the Logdown.disable or Logdown.enable methods.

Logdown.disable('foo') // will disable the instance with *foo* prefix
Logdown.enable('bar') // will enable the instance with *bar* prefix

You can also use wildcards.

Logdown.enable('*') // enables all instances
Logdown.disable('*') // disables all instances
Logdown.enable('foo*') // enables all instances with a prefix starting with *foo*

Use - to do a negation.

// enables all instances but the one with *foo* prefix
Logdown.enable('*', '-foo')
// disables all intances with foo in the prefix, but don't disable *foobar*
Logdown.disable('*foo*', '-foobar')

Recipes

Disabling logging on an instance level

// To disable a given method, just pass a no-op to it
logger.warn = function() {}

// To reenable, attach it again to the prototype
logger.warn = Logdown.prototype.warn

Contributors

203	Caio Gondim
 30	Benny Neugebauer
  5	David Godfrey
  2	Sven Anders Robbestad
  1	Dan Lukinykh
  1	Bent Cardan
  1	Gleb Bahmutov
  1	Panayiotis Lipiridis
  1	netmml

Donating

If you found this library useful and are willing to donate, transfer some bitcoins to 1BqqKiZA8Tq43CdukdBEwCdDD42jxuX9UY or through the URL https://www.coinbase.com/caiogondim

Or via PayPal.me https://www.paypal.me/caiogondim.

caiogondim.com · GitHub @caiogondim · Twitter @caio_gondim

satomixx/logdown.js