Added automatic level detection to connect-logger, depends on http status response.

Update of connect logger example code, compatible with express 3.x

examples/example-connect-logger.js

@@ -1,14 +1,46 @@
-var log4js = require('./lib/log4js');
+//The connect/express logger was added to log4js by danbell. This allows connect/express servers to log using log4js.
-log4js.addAppender(log4js.fileAppender('cheese.log'), 'cheese');
+//https://github.com/nomiddlename/log4js-node/wiki/Connect-Logger
 
-var logger = log4js.getLogger('cheese');
+// load modules
-logger.setLevel('INFO');
+var log4js = require('log4js');
+var express = require("express");
+var app = express();
 
-var app = require('express').createServer();
+//config
+log4js.configure({
+	appenders: [
+		{ type: 'console' },
+		{ type: 'file', filename: 'logs/log4jsconnect.log', category: 'log4jslog' }
+	]
+});
+
+//define logger
+var logger = log4js.getLogger('log4jslog');
+
+// set at which time msg is logged print like: only on error & above
+// logger.setLevel('ERROR');
+
+//express app
 app.configure(function() {
-    app.use(log4js.connectLogger(logger, { level: log4js.levels.INFO }));
+	app.use(express.favicon(''));
+	// app.use(log4js.connectLogger(logger, { level: log4js.levels.INFO }));
+	// app.use(log4js.connectLogger(logger, { level: 'auto', format: ':method :url :status' }));
+
+	//### AUTO LEVEL DETECTION
+	//http responses 3xx, level = WARN
+	//http responses 4xx & 5xx, level = ERROR
+	//else.level = INFO
+	app.use(log4js.connectLogger(logger, { level: 'auto' }));
 });
-app.get('*', function(req,res) {
+
-    res.send('hello world\n <a href="/cheese">cheese</a>\n');
+//route
+app.get('/', function(req,res) {
+	res.send('hello world');
 });
+
+//start app
 app.listen(5000);
+
+console.log('server runing at localhost:5000');
+console.log('Simulation of normal response: goto localhost:5000');
+console.log('Simulation of error response: goto localhost:5000/xxx');

lib/connect-logger.js

@@ -5,7 +5,7 @@ var levels = require("./levels");
  * Options:
  *
  *   - `format`        Format string, see below for tokens
- *   - `level`         A log4js levels instance.
+ *   - `level`         A log4js levels instance. Supports also 'auto'
  *
  * Tokens:
  *
@@ -47,8 +47,7 @@ function getLogger(logger4js, options) {
 
 		// nologs
 		if (nolog && nolog.test(req.originalUrl)) return next();
-
+		if (thislogger.isLevelEnabled(level) || options.level === 'auto') {
-	if (thislogger.isLevelEnabled(level)) {
 
 			var start = +new Date
 			, statusCode
@@ -65,6 +64,15 @@ function getLogger(logger4js, options) {
 				res.writeHead(code, headers);
 				res.__statusCode = statusCode = code;
 				res.__headers = headers || {};
+
+				//status code response level handling
+				if(options.level === 'auto'){
+					level = levels.INFO;
+					if(code >= 300) level = levels.WARN;
+					if(code >= 400) level = levels.ERROR;
+				} else {
+					level = levels.toLevel(options.level, levels.INFO)
+				}
 			};
 
 			// proxy end to output a line to the provided logger.
@@ -72,12 +80,14 @@ function getLogger(logger4js, options) {
 				res.end = end;
 				res.end(chunk, encoding);
 				res.responseTime = +new Date - start;
-		if ('function' == typeof fmt) {
+				if (thislogger.isLevelEnabled(level)) {
+					if (typeof fmt === 'function') {
 						var line = fmt(req, res, function(str){ return format(str, req, res); });
 						if (line) thislogger.log(level, line);
 					} else {
 						thislogger.log(level, format(fmt, req, res));
 					}
+				}
 			};
 		}