slf

Simple Logging Facade

Usage no npm install needed!

<script type="module">
  import slf from 'https://cdn.skypack.dev/slf';
</script>

README

slf

Surikat Log Facade

Install

npm install --save slf

API

Get a logger

import {LoggerFactory} from 'slf';

const log = LoggerFactory.getLogger('name');

const log = LoggerFactory.getLogger('name:subname:subsubname');

Logging

log('Hello!') // As level info
log.log('info', 'Hello!'); // as level info
log.log('Hello!') // as level info (implicit)

log.trace('My Trace');
log.debug('My Debug');
log.info('My Info');
log.warn('My Warning');
log.error('My Error');
log.critical('My Critical Error');

Formatting

Using util.format(...)

  • %s - String.
  • %d - Number (both integer and float).
  • %j - JSON. Replaced with the string '[Circular]' if the argument contains circular references.
  • %% - single percent sign ('%'). This does not consume an argument.
log.info('My Formatted %s', 'Message')
>> 'My Formatted Message'
log.info('My Formatted %d', 123)
>> 'My Formatted 123'
log.info('My Formatted %d', 123)
>> 'My Formatted 123'

Json Formatting

log.info({a: 'aloha'})
>> {a: 'aloha'}
log.info('My Formatted %d', 123)
>> 'My Formatted 123'
log.info('My Formatted %d', 123)
>> 'My Formatted 123'

Configuring a Provider

LoggerFactory.setFactory(<factory-function>);
LoggerFacotry.setFactory(ConsoleLogger);

Writing a Provider

SLF is nothing without a backing logging implementation. The most tiny implementation of a console.log based implementation is shipped with SLF

API

factory-function has the following signature:

function(loggerName) {
  return function(event) {
    //do something with logEvent
  }
}
event = {
  timeStamp: 123456767,
  params: [],
  name: 'logger:name'
  level: 'error'
}