cylon/lib/logger.js

/*
 * logger
 * cylonjs.com
 *
 * Copyright (c) 2013 The Hybrid Group
 * Licensed under the Apache 2.0 license.
*/

"use strict";

var getArgs = function(args) {
  return args.length >= 1 ? [].slice.call(args, 0) : [];
}

// The Logger is a global object to facilitate logging stuff to the console (or
// other output) easily and consistently. It's available anywhere in Cylon, as
// well as in external modules that are loaded into Cylon
global.Logger = {

  // Public: Creates a Logger instance and assigns it to @logger
  //
  // logger - logger object to use. Defaults to a BasicLogger, or a NullLogger if
  // false is supplied
  //
  // Returns the new logger instance
  setup: function(logger) {
    if (logger == null) { logger = new BasicLogger; }

    if (logger === false) {
      this.logger = new NullLogger();
    } else {
      this.logger = logger;
    }

    return this.logger
  },

  toString: function() { return this.logger.toString(); },

  debug: function() {
    var args = getArgs(arguments);
    return this.logger.debug.apply(this.logger, args);
  },

  info: function() {
    var args = getArgs(arguments);
    return this.logger.info.apply(this.logger, args);
  },

  warn: function() {
    var args = getArgs(arguments);
    return this.logger.warn.apply(this.logger, args);
  },

  error: function() {
    var args = getArgs(arguments);
    return this.logger.error.apply(this.logger, args);
  },

  fatal: function() {
    var args = getArgs(arguments);
    return this.logger.fatal.apply(this.logger, args);
  }
};

// The BasicLogger pushes stuff to console.log. Nothing more, nothing less.
var BasicLogger = (function() {
  function BasicLogger() {}

  BasicLogger.prototype.toString = function() { return "BasicLogger"; };

  BasicLogger.prototype.debug = function() {
    var args = getArgs(arguments),
        string = ["D, [" + (new Date().toISOString()) + "] DEBUG -- :"],
        data = string.concat(args.slice());

    return console.log.apply(console, data);
  };

  BasicLogger.prototype.info = function() {
    var args = getArgs(arguments),
        string = ["I, [" + (new Date().toISOString()) + "]  INFO -- :"],
        data = string.concat(args.slice());

    return console.log.apply(console, data);
  };

  BasicLogger.prototype.warn = function() {
    var args = getArgs(arguments),
        string = ["W, [" + (new Date().toISOString()) + "]  WARN -- :"],
        data = string.concat(args.slice());

    return console.log.apply(console, data);
  };

  BasicLogger.prototype.error = function() {
    var args = getArgs(arguments),
        string = ["E, [" + (new Date().toISOString()) + "] ERROR -- :"],
        data = string.concat(args.slice());

    return console.log.apply(console, data);
  };

  BasicLogger.prototype.fatal = function() {
    var args = getArgs(arguments),
        string = ["F, [" + (new Date().toISOString()) + "] FATAL -- :"],
        data = string.concat(args.slice());

    return console.log.apply(console, data);
  };

  return BasicLogger;

})();

// The NullLogger is designed for cases where you want absolutely nothing to
// print to anywhere. Every proxied method from the Logger returns a noop.
var NullLogger = (function() {
  function NullLogger() {}

  NullLogger.prototype.toString = function() { return "NullLogger"; };

  NullLogger.prototype.debug = function() {};
  NullLogger.prototype.info = function() {};
  NullLogger.prototype.warn = function() {};
  NullLogger.prototype.error = function() {};
  NullLogger.prototype.fatal = function() {};

  return NullLogger;

})();