Node-Streamlogger

About

A node.js library for extremely customizable logging

Features

Arbitrary user definable severity levels with debug, info, warn, fatal by default
Custom output formats
Almost all events are listenable
Writing to multiple files simultaneously
Log rotation (reopening log files on demand)

Simple Example (From simple-example.js)

var
  sys = require('sys'),
  http = require('http'),
  streamLogger = require('./lib/streamlogger'),
  logger = new streamLogger.StreamLogger('log1.log');
  //Defaults to info, debug messages will not be logged at info
  logger.level = logger.levels.debug;

http.createServer(function(req, res) {
  //Other default levels are .debug .warn and .fatal
  logger.info("My Info message");

  res.writeHead(200);
  res.write("Hello!");
  res.end();
}).listen(8000);

//If you want to rotate logs, this will re-open the files on sighup
process.addListener("SIGHUP", function() {
  logger.reopen();
});

Full (Ridiculous) Example (Taken from example.js)

var
  sys = require('sys'),
  path = require('path'),
  http = require('http'),
  streamLogger = require('./lib/streamlogger'),
  logger = new streamLogger.StreamLogger('log1.log','log2.log');
   
logger.level = logger.levels.info; //Defaults to info  
logger.emitter
  .addListener('open', function() {
    sys.puts("All streams are open");
  })
  .addListener('error', function(err,logPath) {
    sys.puts("Error: " + err + " while writing to " + logPath);
  })
  .addListener('message', function(message,levelName) {
    sys.puts("Received message: " + message + " with level " + levelName);
  })
  .addListener('loggedMessage', function(message,levelName) {
    //Only gets called for levels allowed by StreamLogger#level
    sys.puts("Logged message: " + message + " with level " + levelName);
  })
  .addListener('close', function() {
    sys.puts("All loggers closed");
  })
  //Alternate style
  .addListener('message-info', function(message) {
    sys.puts("OnlyInfo");
  })
  .addListener('loggedMessage-info', function(message) {
    sys.puts("Logged OnlyInfo");
  });
  
//If you want to rotate logs, this will re-open the files on sighup
process.addListener("SIGHUP", function() {
  logger.reopen();  
});

http.createServer(function(req, res) {
  logger.debug("DebugMsg"); //Won't get printed since log level was set to debug
  logger.info("InfoMsg");
  logger.warn("WarnMsg", function () {sys.puts("MSG flushed to kernel")});
  logger.fatal("FatalMsg");
   
  res.writeHead(200);
  res.write("Hello!");
  res.end();

  //Setting a custom format, note that since this is an async lib
  //setting the format here WILL affect messages outputted prior during this
  //tick, and possibly the next
  logger.format = function(message,levelName) {
    if (levelName == 'warn')
      return "Custom message: " + message;
    else
      return false; //Use the default format
  }
  logger.warn("Should be custom");
  logger.info("Should be standard");

  //Setting custom log levels, note that since this is an async lib this can
  //can cause problems with calls sent earlier in this tick if you delete
  //an existing log level
  var levels = logger.levels;
  levels.extraFatal = levels.fatal + 1;
  //This will not work, as emitter is an existing property of the logger
  //Trying to set this will cause logger to emit an 'error'
  levels.emitter = 20; 
  logger.levels = levels;
  logger.extraFatal("I've been shot through the heart!");
}).listen(8000);

nh7a/node-streamlogger

Node-Streamlogger

About

Features

Simple Example (From simple-example.js)

Full (Ridiculous) Example (Taken from example.js)

Copyright