README

logmorphic

isomorphic logger. you can also save to localStorage.

API

// `<script src='node_modules/logmorphic/index.js></script>` in browser
// or
// `npm install logmorphic` in node

var Logger = Logger || require('logmorphic').Logger;

var format = '[%date] %category %level (%file) - %message';
var appLogger = Logger.getLogger('APP', {
  loglevel: 'DEBUG',
  format: format,
  storage: {
    type: 'localStorage',
    key: 'log',
    limit: 1000 * 10 // 10K
  }
});

var a = { hoge: 100 };
appLogger.trace('the value of "hoge" at', a, 'is', 100);
appLogger.debug('the value of "hoge" at', a, 'is', 100);
appLogger.info('the value of "hoge" at', a, 'is', 100);
appLogger.warn('the value of "hoge" at', a, 'is', 100);
appLogger.error('the value of "hoge" at', a, 'is', 100);
appLogger.fatal('the value of "hoge" at', a, 'is', 100);

output (no TRACE because of loglevel settings to DEBUG)

$ node sample/sample.js
[2015-03-06T07:11:00.036Z] APP DEBUG (sample.js:16) - the value of "hoge" at {"hoge":100} is 100
[2015-03-06T07:11:00.038Z] APP INFO (sample.js:17) - the value of "hoge" at {"hoge":100} is 100
[2015-03-06T07:11:00.039Z] APP WARN (sample.js:18) - the value of "hoge" at {"hoge":100} is 100
[2015-03-06T07:11:00.039Z] APP ERROR (sample.js:19) - the value of "hoge" at {"hoge":100} is 100
[2015-03-06T07:11:00.040Z] APP FATAL (sample.js:20) - the value of "hoge" at {"hoge":100} is 100

TRACE/DEBUG/INFO log outs to STDOUT
WANR/ERROR/FATAL log outs to STDERROR

or open sample/index.html in browser

format

format has these place-holder

%date: current date time with date.toISOString(). change format with override Logger.prototype._date.
%level: level of log name in upper case (DEBUG, INFO, WARN, ERROR, FATAL).
%category: set by getLogger() first arg.
%message: given args to logger. string or serialized number/object/functions.
%file: file name and line number, but has performace consideration.

caution: %file is build by stack trace from Error object because JS doesn't has API for that. this is heavy operation, so consider carefully in production environment.

using file only in develop environment and replace format in production are recomended. if you wanna get more info in production, use logger.trace() or out the given Error instance, which has stack property.

localStorage

save logs to localStorage on browser by specifying storage option. saving are non blocking using setTimeout.

type: storage type, default to 'localStorage' and supported that only now.
key: key of storage column, default to 'logStorage'. keep all log in 1 column of storage for avoid occupy storage, and save order of log.
limit: limit for save to storage, defalut to 20K. remove as FIFO

install & commands

$ npm install logmorphic

you can call all build task from npm run-scripts. (actually it calls gulp task, please see package.json scripts directive.

$ npm install
$ npm test
$ npm run lint

TypeScript support

use logmorphic.d.ts for typescript.

FAQ

how to save logs to the file ?

logmorphic currentry doesn't support logging to file. because system usually running with process management tools like supervisord, forever, monit etc they usually have logging support which gets log from STDOUT/STDERROR, and saves to file, logserver, fluentd etc, and also log-rotation, log-versioning, log-destroy or so. just use that.

CHANGELOG

v0.0.5: update dependencies and fix for new .eslintrc

License

MIT: http://jxck.mit-license.org/

Usage no npm install needed!