2 * loglevel - https://github.com/pimterry/loglevel
4 * Copyright (c) 2013 Tim Perry
5 * Licensed under the MIT license.
7 (function (root, definition) {
9 if (typeof define === 'function' && define.amd) {
11 } else if (typeof module === 'object' && module.exports) {
12 module.exports = definition();
14 root.log = definition();
19 // Slightly dubious tricks to cut down minimized file size
20 var noop = function() {};
21 var undefinedType = "undefined";
22 var isIE = (typeof window !== undefinedType) && (typeof window.navigator !== undefinedType) && (
23 /Trident\/|MSIE /.test(window.navigator.userAgent)
34 // Cross-browser bind equivalent that works at least back to IE6
35 function bindMethod(obj, methodName) {
36 var method = obj[methodName];
37 if (typeof method.bind === 'function') {
38 return method.bind(obj);
41 return Function.prototype.bind.call(method, obj);
43 // Missing bind shim or IE8 + Modernizr, fallback to wrapping
45 return Function.prototype.apply.apply(method, [obj, arguments]);
51 // Trace() doesn't print the message in IE, so for that case we need to wrap it
52 function traceForIE() {
54 if (console.log.apply) {
55 console.log.apply(console, arguments);
57 // In old IE, native console methods themselves don't have apply().
58 Function.prototype.apply.apply(console.log, [console, arguments]);
61 if (console.trace) console.trace();
64 // Build the best logging method possible for this env
65 // Wherever possible we want to bind, not wrap, to preserve stack traces
66 function realMethod(methodName) {
67 if (methodName === 'debug') {
71 if (typeof console === undefinedType) {
72 return false; // No method possible, for now - fixed later by enableLoggingWhenConsoleArrives
73 } else if (methodName === 'trace' && isIE) {
75 } else if (console[methodName] !== undefined) {
76 return bindMethod(console, methodName);
77 } else if (console.log !== undefined) {
78 return bindMethod(console, 'log');
84 // These private functions always need `this` to be set properly
86 function replaceLoggingMethods(level, loggerName) {
87 /*jshint validthis:true */
88 for (var i = 0; i < logMethods.length; i++) {
89 var methodName = logMethods[i];
90 this[methodName] = (i < level) ?
92 this.methodFactory(methodName, level, loggerName);
95 // Define log.log as an alias for log.debug
96 this.log = this.debug;
99 // In old IE versions, the console isn't present until you first open it.
100 // We build realMethod() replacements here that regenerate logging methods
101 function enableLoggingWhenConsoleArrives(methodName, level, loggerName) {
103 if (typeof console !== undefinedType) {
104 replaceLoggingMethods.call(this, level, loggerName);
105 this[methodName].apply(this, arguments);
110 // By default, we use closely bound real methods wherever possible, and
111 // otherwise we wait for a console to appear, and then try again.
112 function defaultMethodFactory(methodName, level, loggerName) {
113 /*jshint validthis:true */
114 return realMethod(methodName) ||
115 enableLoggingWhenConsoleArrives.apply(this, arguments);
118 function Logger(name, defaultLevel, factory) {
121 var storageKey = "loglevel";
123 storageKey += ":" + name;
126 function persistLevelIfPossible(levelNum) {
127 var levelName = (logMethods[levelNum] || 'silent').toUpperCase();
129 if (typeof window === undefinedType) return;
131 // Use localStorage if available
133 window.localStorage[storageKey] = levelName;
137 // Use session cookie as fallback
139 window.document.cookie =
140 encodeURIComponent(storageKey) + "=" + levelName + ";";
144 function getPersistedLevel() {
147 if (typeof window === undefinedType) return;
150 storedLevel = window.localStorage[storageKey];
153 // Fallback to cookies if local storage gives us nothing
154 if (typeof storedLevel === undefinedType) {
156 var cookie = window.document.cookie;
157 var location = cookie.indexOf(
158 encodeURIComponent(storageKey) + "=");
159 if (location !== -1) {
160 storedLevel = /^([^;]+)/.exec(cookie.slice(location))[1];
165 // If the stored level is not valid, treat it as if nothing was stored.
166 if (self.levels[storedLevel] === undefined) {
167 storedLevel = undefined;
175 * Public logger API - see https://github.com/pimterry/loglevel for details
181 self.levels = { "TRACE": 0, "DEBUG": 1, "INFO": 2, "WARN": 3,
182 "ERROR": 4, "SILENT": 5};
184 self.methodFactory = factory || defaultMethodFactory;
186 self.getLevel = function () {
190 self.setLevel = function (level, persist) {
191 if (typeof level === "string" && self.levels[level.toUpperCase()] !== undefined) {
192 level = self.levels[level.toUpperCase()];
194 if (typeof level === "number" && level >= 0 && level <= self.levels.SILENT) {
195 currentLevel = level;
196 if (persist !== false) { // defaults to true
197 persistLevelIfPossible(level);
199 replaceLoggingMethods.call(self, level, name);
200 if (typeof console === undefinedType && level < self.levels.SILENT) {
201 return "No console available for logging";
204 throw "log.setLevel() called with invalid level: " + level;
208 self.setDefaultLevel = function (level) {
209 if (!getPersistedLevel()) {
210 self.setLevel(level, false);
214 self.enableAll = function(persist) {
215 self.setLevel(self.levels.TRACE, persist);
218 self.disableAll = function(persist) {
219 self.setLevel(self.levels.SILENT, persist);
222 // Initialize with the right level
223 var initialLevel = getPersistedLevel();
224 if (initialLevel == null) {
225 initialLevel = defaultLevel == null ? "WARN" : defaultLevel;
227 self.setLevel(initialLevel, false);
236 var defaultLogger = new Logger();
238 var _loggersByName = {};
239 defaultLogger.getLogger = function getLogger(name) {
240 if (typeof name !== "string" || name === "") {
241 throw new TypeError("You must supply a name when creating a logger.");
244 var logger = _loggersByName[name];
246 logger = _loggersByName[name] = new Logger(
247 name, defaultLogger.getLevel(), defaultLogger.methodFactory);
252 // Grab the current global log variable in case of overwrite
253 var _log = (typeof window !== undefinedType) ? window.log : undefined;
254 defaultLogger.noConflict = function() {
255 if (typeof window !== undefinedType &&
256 window.log === defaultLogger) {
260 return defaultLogger;
263 defaultLogger.getLoggers = function getLoggers() {
264 return _loggersByName;
267 return defaultLogger;