log4js

Complete logger for JS browser development

Browser log management.

Allows to manage all logs displayed in browser console.

• Permits, if browser is launched with required configuration, to append these log in an external file.

Inspired by Log4J java library.

INSTALLATION

npm install @g0tan/log4js

USAGE

Simply use log.<method>(message) method.

@param message can be string or array of strings

If message is an array, first message will be used as title of following grouped messages

METHODS

• All log levels :
  • trace(message)
  • debug(message)
  • info(message)
  • warn(message)
  • error(message)
  • fatal(message)
• downloadFile() : download file (max 2500 lines)
• tail(lineCount): get last logs
• search(term): search for a specific string in logs
• printLog(): show in console the entire stored log
• clearFile(): erase all stored logs

CONFIGURATION

You can define these constant

• LOG_CONFIG with following values.
  All are optionnals. Default values are set.

• level: minimum allowed log level. all message above this level will be ignored.
  Choose among LEVELS const values: TRACE, DEBUG, INFO, WARN, ERROR, FATAL
  default: WARN

• file: Store all logs in a local storage file.
  Allows to print & download all logs
  Set null for disabling this feature.
  Messages in file storage are not formatted
  default: null *live: Display all messages in console.
  Print messages in browser console.
  default: false
  Note that if file & live are not set, log4js is useless ;-)
  Message will be formatted in console

• prefix: Prefix before all log message (usefull for log distinguishing)
  default: ""

• date_format: date format for displaying message.
  See momentJs documentation.
  If momentJS is not loaded, this parameter is useless.
  default: "YYMMDD-HHmmss"

• debug: enable Log4JS debug messages
  default: false

DEPENDENCIES

• momentjs is not required but allows to format date
• debugout.js for file outputting

FULL EXAMPLE

const LOG_CONFIG = {
	DEBUG: true, 
	LEVEL: Log4JS.LEVELS.TRACE, 
	FILE: "/var/log/test-log4js.log",
	PREFIX: "MyLogger>"
};
var log = new Log4JS(LOG_CONFIG, "MyLogger");
log.debug("Info message");
	log.info("Grouped messages", "First message", "Second message");