Merge pull request #187 from jci-fox/addHasLogger

adding ability to check if a logger exists

lib/log4js.js

@@ -62,6 +62,11 @@ var events = require('events')
   replaceConsole: false
 };
 
+function hasLogger(logger) {
+  return loggers.hasOwnProperty(logger);
+}
+
+
 /**
  * Get a logger instance. Instance is cached on categoryName level.
  * @param  {String} categoryName name of category to log to.
@@ -76,7 +81,7 @@ function getLogger (categoryName) {
   }
 
   var appenderList;
-  if (!loggers[categoryName]) {
+  if (!hasLogger(categoryName)) {
     // Create the logger for this name if it doesn't already exist
     loggers[categoryName] = new Logger(categoryName);
     if (appenders[categoryName]) {
@@ -115,7 +120,7 @@ function addAppender () {
     
     if (category === ALL_CATEGORIES) {
       addAppenderToAllLoggers(appender);
-    } else if (loggers[category]) {
+    } else if (hasLogger(category)) {
       loggers[category].addListener("log", appender);
     }
   });
@@ -123,7 +128,7 @@ function addAppender () {
 
 function addAppenderToAllLoggers(appender) {
   for (var logger in loggers) {
-    if (loggers.hasOwnProperty(logger)) {
+    if (hasLogger(logger)) {
       loggers[logger].addListener("log", appender);
     }
   }
@@ -139,7 +144,7 @@ function addAppenderToCategory(appender, category) {
 function clearAppenders () {
   appenders = {};
   for (var logger in loggers) {
-    if (loggers.hasOwnProperty(logger)) {
+    if (hasLogger(logger)) {
       loggers[logger].removeAllListeners("log");
     }
   }
@@ -304,6 +309,7 @@ function loadAppender(appender) {
 module.exports = {
   getLogger: getLogger,
   getDefaultLogger: getDefaultLogger,
+  hasLogger: hasLogger,
   
   addAppender: addAppender,
   loadAppender: loadAppender,