node-file-logger v0.9.5

Node File Logger

A simple logger for logging exceptions and error details in a log file.

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 | \ | | ___   __| | ___  |  ___(_) | ___  | |    ___   __ _  __ _  ___ _ __ 
 |  \| |/ _ \ / _` |/ _ \ | |_  | | |/ _ \ | |   / _ \ / _` |/ _` |/ _ \ '__|
 | |\  | (_) | (_| |  __/ |  _| | | |  __/ | |__| (_) | (_| | (_| |  __/ |   
 |_| \_|\___/ \__,_|\___| |_|   |_|_|\___| |_____\___/ \__, |\__, |\___|_|   
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Docs & Features

Dependencies

moment.js moment-timezone.js node-stringify.js

Suports all logging levels

• DEBUG: The DEBUG Level designates fine-grained informational events that are most useful to debug an application.
• TRACE: The TRACE Level designates finer-grained informational events than the DEBUG
• INFO: The INFO level designates informational messages that highlight the progress of the application at coarse-grained level.
• WARN: The WARN level designates potentially harmful situations.
• ERROR: The ERROR level designates error events that might still allow the application to continue running.
• FATAL: The FATAL level designates very severe error events that will presumably lead the application to abort.

Create date-wise log files

It has an option to create a new log file for the current date which will be named like YYYY-MM-DD-log.log

Extras

• Allows logging the service name & method name
• Allows logging a short error message and an entire error object (optional)
• Error objects are stringified and then logged to the log file

Has a callback

It allows you to run a callback after the logging process.

Steps to use

Installation

npm install node-file-logger --save

Create instance of Node file logger

// Ceate an instance of node file logger
const log = require('node-file-logger');
log.SetUserOptions(options); // Options are optional

Using options

// It is recommended to set options in a separate module and include it in the code
// Everything in the example below are default values
const options = {
  timeZone: 'America/Los_Angeles',
  folderPath: './logs/',      
  dateBasedFileNaming: true,
  // Required only if dateBasedFileNaming is set to false
  fileName: 'All_Logs',   
  // Required only if dateBasedFileNaming is set to true
  fileNamePrefix: 'Logs_',
  fileNameSuffix: '',
  fileNameExtension: '.log',     
  
  dateFormat: 'YYYY-MM-DD',
  timeFormat: 'HH:mm:ss.SSS',
  logLevel: 'debug',
  onlyFileLogging: true
}

// Note: If you set dateBasedFileNaming to false, then a log file will be created at the folder path with the provided fileName.
// If set to true then a logfile will be created with the name <fileName> provided in the options

log.SetUserOptions(options); 

Examples

Simple logging to a file with date-based log file naming

const options = {
  folderPath: './logs/',
  dateBasedFileNaming: true,
  fileNamePrefix: 'DailyLogs_',
  fileNameExtension: '.log',    
  dateFormat: 'YYYY_MM_D',
  timeFormat: 'h:mm:ss A',
}

const log = require('node-file-logger');
log.SetUserOptions(options);

// Log a simple error message
log.Info('Some informational log message');

// *****************************************************
// Ouput in Logfile: 
// File name : ./logs/Logs_2018_02_23.log
// 5:52:28 PM | Info | Some informational log message
// *****************************************************

// Log an error message with service and method names
log.Error('Something has failed!', 'Some service', 'Some method');

// *****************************************************
// Ouput in Logfile: 
// File name : ./logs/Logs_2018_02_23.log
// 5:52:28 PM | Error | Service: Some service | Method: Some method | Some error message
// *****************************************************

// Log an fatal error message with service and method names and error object
log.Fatal('Something has failed!', 'Some service', 'Some method', errorObj);

// *****************************************************
// Ouput in Logfile: 
// File name : ./logs/Logs_2018_02_23.log
// 5:52:28 PM | Fatal | Service: Some service | Method: Some method | Something is broken
{
  unhandledException: Something serious has happened
}
// *****************************************************

// Log an error message with callback
log.Info('Something has failed!', null, null, null, function() {
  // Do something
});

Simple logging to a file without date-based file naming

const options = {
  folderPath: './logs/',
  dateBasedFileNaming: false,
  fileName: 'All_Logs.log', 
  dateFormat: 'YYYY_MM_D',
  timeFormat: 'h:mm:ss A',
}

const log = require('node-file-logger');
log.SetUserOptions(options);

// Log a simple error message
log.Info('Some informational log message');


// *****************************************************
// Ouput in Logfile: 
// File name : ./logs/All_Logs.log
// 2018_02_23 5:52:28 PM | Info | Some informational log message
// *****************************************************

API Reference

Methods:

SetUserOptions()

Sets user options for node file logger

Details of the configuration object

Details of log levels

'prod' and 'prod-trace' levels are suitable for production releases

Debug()

Logs a debug message in the log file

Trace()

Logs a trace message in the log file

Info()

Logs a informational message in the log file

Warn()

Logs a warning message in the log file

Error()

Logs a error message in the log file

Fatal()

Logs a fatal error message in the log file

Log()

Used to log any kind of log message in the log file (Custom Log level)

License

Apache 2.0