style/style.js

color in your node.js console, without monkeypatching

/*
style.js 

Copyright (c) 2010 Alexis Sellier (cloudhead) , Marak Squires, Dominic Tarr

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

this is based on colors.js by Alexis Sellier (cloudhead) & Marak Squires

*/

exports = module.exports = style
exports.error = require('./error')

function style(string){
  return new Styled(string)
}
function unstyled(string){
  var styled = new Styled(string)
  styled.enable = false
  return styled 
}
unstyled.enable = style.enable = function (on){
  return on ? style : unstyled
}

exports.stylize = stylize
function stylize(str, style) {
  if(style == 'rainbow'){
    var rainbowcolors = ['red','yellow','green','blue','magenta']; //RoY G BiV
    var exploded = str.split("");
    var i=0;
    exploded = exploded.map(function(letter) {
      if (letter==" ") {
        return letter;
      } 
      else {
        return stylize(letter,rainbowcolors[i++ % rainbowcolors.length]);
      }
    });
    return exploded.join("");

  }

  return '\033[' + styles[style][0] + 'm' + str +
         '\033[' + styles[style][1] + 'm';
};

function Styled (_string){
  var string = _string
    , _lpad = 0
    , _rpad = 0
    , _rc = ' '
    , _lc = ' '
  this.styles = []
  this.enable = true
  this.__defineGetter__('length',function (){
    return _lpad + (destyle("" + string).length) + _rpad
  })
  this.__defineSetter__('_string',function (s){
    return string = s
  })
  this.__defineGetter__('_string',function (s){
    return string
  })
  this.__defineGetter__('to_s',function (){
    return this.toString()
  })
  this.__defineGetter__('styler',function (){
    var self = this
    return function (x,off){
      var _string = string
        , _enable = self.enable
        self.enable = !off
      string = x
      var toReturn = self.toString()
      string = _string
      this.enable = _enable
      return toReturn
    }
  })
  this.toString = toString
  function pad(l,c){
    var pad = ''
      , _c = c
    if(_c instanceof Styled) // make pad aware of style, and not duplicate the characters too much!
      c = _c._string
    for(var i = 0; i < l; i ++) { pad += c }
    if(_c instanceof Styled){
      _c._string = pad
      return _c
      }
    
    return pad
  }
  function toString(){
    var newString = string
  
    if(this.enable)
    this.styles.forEach(function (style){
      newString = stylize(newString,style)
    })
  
    return pad(_lpad,_lc) + newString + pad(_rpad,_rc)
  }
  this.lpad = lpad
  this.rpad = rpad
  
  function lpad (pad,c){
    _lpad = this.length < pad ? _lpad = pad - this.length : 0
    _lc = c || _lc
    return this
  }
  function rpad (pad,c){
    _rpad = this.length < pad ? _rpad = pad - this.length : 0
    _rc = c || _rc 
    return this
  }
}

var styles = {
  //styles
  'bold'      : [1,  22],
  'italic'    : [3,  23],
  'underline' : [4,  24],
  'inverse'   : [7,  27],
  //grayscale
  'white'     : [37, 39],
  'grey'      : [90, 39],
  'black'     : [90, 39],
  //colors
  'blue'      : [34, 39],
  'cyan'      : [36, 39],
  'green'     : [32, 39],
  'magenta'   : [35, 39],
  'red'       : [31, 39],
  'yellow'    : [33, 39],
  };

exports.styles = Object.keys(styles).concat(['rainbow'])
exports.styles.forEach(function (style) {
  Object.defineProperty(Styled.prototype, style, {
    get: function () {
    this.styles.push(style)
    return this
    }
  });
});
var code = /\u001b\[\d+m/g

exports.destyle = destyle 
function destyle (s){
  return ("" + s).replace(code,'')
}