michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: var LogController = {}; //create the logger object
michael@0: 
michael@0: LogController.counter = 0; //current log message number
michael@0: LogController.listeners = [];
michael@0: LogController.logLevel = {
michael@0:     FATAL: 50,
michael@0:     ERROR: 40,
michael@0:     WARNING: 30,
michael@0:     INFO: 20,
michael@0:     DEBUG: 10
michael@0: };
michael@0: 
michael@0: /* set minimum logging level */
michael@0: LogController.logLevelAtLeast = function(minLevel) {
michael@0:     if (typeof(minLevel) == 'string') {
michael@0:         minLevel = LogController.logLevel[minLevel];
michael@0:     }
michael@0:     return function (msg) {
michael@0:         var msgLevel = msg.level;
michael@0:         if (typeof(msgLevel) == 'string') {
michael@0:             msgLevel = LogController.logLevel[msgLevel];
michael@0:         }
michael@0:         return msgLevel >= minLevel;
michael@0:     };
michael@0: };
michael@0: 
michael@0: /* creates the log message with the given level and info */
michael@0: LogController.createLogMessage = function(level, info) {
michael@0:     var msg = {};
michael@0:     msg.num = LogController.counter;
michael@0:     msg.level = level;
michael@0:     msg.info = info;
michael@0:     msg.timestamp = new Date();
michael@0:     return msg;
michael@0: };
michael@0: 
michael@0: /* helper method to return a sub-array */
michael@0: LogController.extend = function (args, skip) {
michael@0:     var ret = [];
michael@0:     for (var i = skip; i<args.length; i++) {
michael@0:         ret.push(args[i]);
michael@0:     }
michael@0:     return ret;
michael@0: };
michael@0: 
michael@0: /* logs message with given level. Currently used locally by log() and error() */
michael@0: LogController.logWithLevel = function(level, message/*, ...*/) {
michael@0:     var msg = LogController.createLogMessage(
michael@0:         level,
michael@0:         LogController.extend(arguments, 1)
michael@0:     );
michael@0:     LogController.dispatchListeners(msg);
michael@0:     LogController.counter += 1;
michael@0: };
michael@0: 
michael@0: /* log with level INFO */
michael@0: LogController.log = function(message/*, ...*/) {
michael@0:     LogController.logWithLevel('INFO', message);
michael@0: };
michael@0: 
michael@0: /* log with level ERROR */
michael@0: LogController.error = function(message/*, ...*/) {
michael@0:     LogController.logWithLevel('ERROR', message);
michael@0: };
michael@0: 
michael@0: /* send log message to listeners */
michael@0: LogController.dispatchListeners = function(msg) {
michael@0:     for (var k in LogController.listeners) {
michael@0:         var pair = LogController.listeners[k];
michael@0:         if (pair.ident != k || (pair[0] && !pair[0](msg))) {
michael@0:             continue;
michael@0:         }
michael@0:         pair[1](msg);
michael@0:     }
michael@0: };
michael@0: 
michael@0: /* add a listener to this log given an identifier, a filter (can be null) and the listener object */
michael@0: LogController.addListener = function(ident, filter, listener) {
michael@0:     if (typeof(filter) == 'string') {
michael@0:         filter = LogController.logLevelAtLeast(filter);
michael@0:     } else if (filter !== null && typeof(filter) !== 'function') {
michael@0:         throw new Error("Filter must be a string, a function, or null");
michael@0:     }
michael@0:     var entry = [filter, listener];
michael@0:     entry.ident = ident;
michael@0:     LogController.listeners[ident] = entry;
michael@0: };
michael@0: 
michael@0: /* remove a listener from this log */
michael@0: LogController.removeListener = function(ident) {
michael@0:     delete LogController.listeners[ident];
michael@0: };