A simple logging library for Node.js
Installing
$ npm install basic-log
Basic usage
var log = require('basic-log');
log('Hello!');
Output:
2013-01-19 09:01:53.478 Hello!
log takes a single argument, converts it to string, and prints it to console.
Other log levels:
log.d('Hello!');
log.i('Hello!');
log.w('Hello!');
log.e('Hello!');
Output:
2013-01-19 09:03:17.671 [debug] Hello!
2013-01-19 09:03:17.671 [info] Hello!
2013-01-19 09:03:17.671 [warn] Hello!
2013-01-19 09:03:17.671 [error] Hello!
Suppressing one or more levels
log.setLevel('info');
log.d('Will not be logged');
log.i('Will be logged');
log.setLevel accepts the following levels: 'none', 'debug', 'warn', 'info', 'debug'. Each level includes the levels preceding it. 'all' is an alias for 'debug'.
Changing the date format
By default, the date format is YYYY-MM-DD hh:mm:ss:mmm in UTC time.
Change it by setting date:
log.date = function() {
return new Date().getTime() + ' ';
}
log('Hello!');
Output:
1358586277536 Hello!
Or get rid of the time altogether:
log.date = function() {
return '';
}
log('Hello!');
Output:
Hello!
Changing the output
By default, messages are written using console.log.
Change it by setting output:
log.output = function(message) {
console.err(message);
}
log('Hello!'); // prints to stderr
Or make it return a value if you like:
log.output = function(message) {
return message.toUpperCase();
}
console.log(log('Hello!'));
Output:
HELLO!
Creating new instances
If want to avoid changing the global log, you make create a new instance:
var Log = require('basic-log').Log;
var log = new Log(<custom functions>);
A typical use case would be to create your own log module and use it:
lib/my-log.js:
var Log = require('basic-log').Log;
module.exports = new Log({
date: function() { return new Date().getTime() + ' '; }
});
my-app.js:
var log = require('./lib/my-log');
log('Hi!');