reduced complex function to smaller ones

lib/log4js.js

@@ -111,23 +111,31 @@ function addAppender () {
   }
   
   args.forEach(function(category) {
-    if (!appenders[category]) {
+    addAppenderToCategory(appender, category);
-      appenders[category] = [];
-    }
-    appenders[category].push(appender);
     
     if (category === ALL_CATEGORIES) {
-      for (var logger in loggers) {
+      addAppenderToAllLoggers(appender);
-        if (loggers.hasOwnProperty(logger)) {
-          loggers[logger].addListener("log", appender);
-        }
-      }
     } else if (loggers[category]) {
       loggers[category].addListener("log", appender);
     }
   });
 }
 
+function addAppenderToAllLoggers(appender) {
+  for (var logger in loggers) {
+    if (loggers.hasOwnProperty(logger)) {
+      loggers[logger].addListener("log", appender);
+    }
+  }
+}
+
+function addAppenderToCategory(appender, category) {
+  if (!appenders[category]) {
+    appenders[category] = [];
+  }
+  appenders[category].push(appender);
+}
+
 function clearAppenders () {
   appenders = {};
   for (var logger in loggers) {