lgr

Generic Logger

Idea is to give best of Winston, Bunyan and npmlog

Usage

Eactly like npmlog , but giving a snippet here

// Use 1 logger throughout application
var log = require('lgr');

// App invoked with -v ? set verbose level
log.setLevel('verbose');

log.info('gateway', 'Check', null);

log levels

For each log level name and priority are mandatory arguments. Mandatory args

• name
• priority

Optional args

• Style ( default info style )
• Stream ( default process.stdout)
• LogFormat ( default )
• tsFormat (default YYYY-MM-DD HH:mm:ss)

log.setLevel('verbose'); // set level 

log.getLevel();
// -> now returns 'verbose'

log.getLevels(); // You can query the levels you can `setLevel` to
/*
Returns:
{ silly: -Infinity,
  verbose: 1000,
  info: 2000,
  http: 3000,
  warn: 4000,
  error: 5000,
  silent: Infinity,
  critical: 6000 }
*/

log.addLevel('wall', 3500); // Add custom levels
log.addLevel('hell', 6000, {  fg : 'red', 'bg' : 'yellow'  }, 'hell!', '<%= prefix %> <%= ts %> <%= ram %> [<%= uptime %>] [<%= count %>] <%= __FILE__ %>:<%= __FUNC__ %>:<%= __LINE__ %>:<%= __COLM__ %> <%= msg %>', process.stderr);


// Edit level setting : done by same function call
// log.editLevel(levelName, property, value) , properties are ['weight', 'style', 'dispPrefix', 'logFormat', 'stream']

log.editLevel('info', 'stream', someStream)

log Formats

Variables

• prefix : info, error , etc. from log level
• msg : The message that was passed to log
• ram : will give memory usage from process.memoryusage
• ts : current timestamp
• uptime : uptime of process
• pid : process id
• count : Log count , global for this process
• hostname : system hostname
• FUNC : will invoke stacktrace and last visited function of code
• FILE : will invoke stacktrace and last visited file at this log
• LINE : will invoke stacktrace and last visited line at this log
• COLM : will invoke stacktrace and show column number.

// and "__FUNC__", "__FILE__", "__LINE__", "__COLM__". C Forever. :D
log.setLogFormat('<%= ts %> [<%= uptime %>] ');

//you can also set log formats for specific log levels
log.setLogFormat('info','<%= ts %>');

Colors

• Only Prefix colors can be user controlled.
• Different color for system generated information.
• The user specified data is in white.

timestamp format

To change timeformat for each level please change by editLevel To change timeformat for all levels throughout

log.updateTsFormat('YYYY-MM-DD HH:MM:SS.sss');

NOTE : updateTsFormat actually gets all levels and overwrite the timestamp for each level.

Features

• Priority based log levels.
• Streams can be tied to each level making it easier to redirect log anywhere.
• User defined formatted logs with os specific and stack information.

Theory , design decisions

• Decision to not incorporate file saving, logs in rabbitmq and to use streams instead comes from the learning of winston which incorporate transport system. this is designed to be leightweight and users must implement their own stream to make use of log outouts.

ToDo and improvements : See Github Issues

ChangeLog : See Tags

Test

Just run 'npm test'