logger.js

// ==UserScript==

'use strict';

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

/*
 *  Logger class
 *  - debug
 *  - info
 *  - error
 *  - warn
 *  - setLevel
 */

var Log = function () {
    function Log() {
        var level = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 'INFO';

        _classCallCheck(this, Log);

        this.logLevel = level;
    }

    _createClass(Log, [{
        key: 'log',
        value: function log(args) {
            args = Array.prototype.slice.call(args);
            args.unshift('[' + this.logLevel + '] ');
            var console = window.console;
            if (console && console.log && console.log.apply) {
                try {
                    console.log.apply(this, args);
                } catch (e) {}            }
        }
    }, {
        key: 'distinctLog',
        value: function distinctLog(level, args) {
            var prevLevel = this.logLevel;
            this.logLevel = level;
            this.log(args);
            this.logLevel = prevLevel;
        }
    }, {
        key: 'debug',
        value: function debug(args) {
            if (this.logLevel === 'DEBUG') {
                this.log(args);
            }
        }
    }, {
        key: 'info',
        value: function info(args) {
            if (this.logLevel === 'INFO') {
                this.log("INFO", arguments);
            }
        }
    }, {
        key: 'error',
        value: function error(args) {
            this.distinctLog('ERROR', args);
        }
    }, {
        key: 'warn',
        value: function warn(args) {
            this.distinctLog('WARN', args);
        }
    }, {
        key: 'setLevel',
        value: function setLevel(level) {
            this.logLevel = level;
        }
    }]);

    return Log;
}();

var log = new Log();

log.warn('Warn');
log.debug('Debug');