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 defaultLevel = defaultLevel == null ? "WARN" : defaultLevel;
123 var storageKey = "loglevel";
124 if (typeof name === "string") {
125 storageKey += ":" + name;
126 } else if (typeof name === "symbol") {
127 storageKey = undefined;
130 function persistLevelIfPossible(levelNum) {
131 var levelName = (logMethods[levelNum] || 'silent').toUpperCase();
133 if (typeof window === undefinedType || !storageKey) return;
135 // Use localStorage if available
137 window.localStorage[storageKey] = levelName;
141 // Use session cookie as fallback
143 window.document.cookie =
144 encodeURIComponent(storageKey) + "=" + levelName + ";";
148 function getPersistedLevel() {
151 if (typeof window === undefinedType || !storageKey) return;
154 storedLevel = window.localStorage[storageKey];
157 // Fallback to cookies if local storage gives us nothing
158 if (typeof storedLevel === undefinedType) {
160 var cookie = window.document.cookie;
161 var location = cookie.indexOf(
162 encodeURIComponent(storageKey) + "=");
163 if (location !== -1) {
164 storedLevel = /^([^;]+)/.exec(cookie.slice(location))[1];
169 // If the stored level is not valid, treat it as if nothing was stored.
170 if (self.levels[storedLevel] === undefined) {
171 storedLevel = undefined;
177 function clearPersistedLevel() {
178 if (typeof window === undefinedType || !storageKey) return;
180 // Use localStorage if available
182 window.localStorage.removeItem(storageKey);
186 // Use session cookie as fallback
188 window.document.cookie =
189 encodeURIComponent(storageKey) + "=; expires=Thu, 01 Jan 1970 00:00:00 UTC";
195 * Public logger API - see https://github.com/pimterry/loglevel for details
201 self.levels = { "TRACE": 0, "DEBUG": 1, "INFO": 2, "WARN": 3,
202 "ERROR": 4, "SILENT": 5};
204 self.methodFactory = factory || defaultMethodFactory;
206 self.getLevel = function () {
210 self.setLevel = function (level, persist) {
211 if (typeof level === "string" && self.levels[level.toUpperCase()] !== undefined) {
212 level = self.levels[level.toUpperCase()];
214 if (typeof level === "number" && level >= 0 && level <= self.levels.SILENT) {
215 currentLevel = level;
216 if (persist !== false) { // defaults to true
217 persistLevelIfPossible(level);
219 replaceLoggingMethods.call(self, level, name);
220 if (typeof console === undefinedType && level < self.levels.SILENT) {
221 return "No console available for logging";
224 throw "log.setLevel() called with invalid level: " + level;
228 self.setDefaultLevel = function (level) {
229 defaultLevel = level;
230 if (!getPersistedLevel()) {
231 self.setLevel(level, false);
235 self.resetLevel = function () {
236 self.setLevel(defaultLevel, false);
237 clearPersistedLevel();
240 self.enableAll = function(persist) {
241 self.setLevel(self.levels.TRACE, persist);
244 self.disableAll = function(persist) {
245 self.setLevel(self.levels.SILENT, persist);
248 // Initialize with the right level
249 var initialLevel = getPersistedLevel();
250 if (initialLevel == null) {
251 initialLevel = defaultLevel;
253 self.setLevel(initialLevel, false);
262 var defaultLogger = new Logger();
264 var _loggersByName = {};
265 defaultLogger.getLogger = function getLogger(name) {
266 if ((typeof name !== "symbol" && typeof name !== "string") || name === "") {
267 throw new TypeError("You must supply a name when creating a logger.");
270 var logger = _loggersByName[name];
272 logger = _loggersByName[name] = new Logger(
273 name, defaultLogger.getLevel(), defaultLogger.methodFactory);
278 // Grab the current global log variable in case of overwrite
279 var _log = (typeof window !== undefinedType) ? window.log : undefined;
280 defaultLogger.noConflict = function() {
281 if (typeof window !== undefinedType &&
282 window.log === defaultLogger) {
286 return defaultLogger;
289 defaultLogger.getLoggers = function getLoggers() {
290 return _loggersByName;
293 // ES6 default export, for compatibility
294 defaultLogger['default'] = defaultLogger;
296 return defaultLogger;