l4js

L4js (Logging For JavaScript) Intro

l4js is a lightweight, user-friendly logging utility designed to simplify the logging process for JavaScript and Node.js applications. Unlike other npm logging packages, l4js focuses on ease of use, reusability, and a streamlined "create once, use everywhere" pattern. With l4js, there's no need for complex instantiation or configuration—just quick, intuitive logging that gets out of your way.

Key features include:

• Small and Lightweight: Minimal footprint with no unnecessary dependencies.
• Easy to Use: Simple setup and straightforward API, perfect for developers of all experience levels.
• Reusable: Design once, and reuse your logger configuration across your entire project.
• No Complex Instantiation: Say goodbye to cumbersome configuration; l4js gets you logging instantly.
• l4js is the perfect tool for developers seeking a hassle-free logging solution that just works.

Quick Start

Getting Started is easy and quick !

install l4js

$ npm install l4js@latest

Simple Logging Examples

Import The Library into project or app.

/* Import l4js into your Application */
let {L4js} = require("L4js");

Create an options or configuration Object

let options = {
        dateFormat:"",     // A Date Format Default is "yyyy-MM-dd"
        filePath:"",       // The File path where the log file file should be placed if logging to file is enabled 
        logLevel:"*",      // The Log Level Default is * (Supports All Levels). you can choose info|warn|error|debug
        logToFile: false,  // boolean flag to enable or disable logging to a file default is false
        fileName: null,    // Your desired log filename if logging to file is enabled Default is "l4js.yyyy-MM-dd.log"
        batchSize: 0,      // Log Queue Batch size (default is 0)  
        flushInterval: 0   // The Log Queue flush interval to clear and write logs from a log queue 
} 

Initialize the Logger

let logger = L4js.initialize(options) 

Log a Simple Info Message

logger.info("This is a Info Message");

Log a Warning Message

logger.warn("This is a Warning Message");

Log A Error Message

logger.error(new Error("I messed up Something"));

Log a Debug Message

logger.debug("This is a Debug Message, In some app.. What is going on? ");

Example Log Output:

# INFO Message 
2024-08-23 INFO (60103) "This is a Info Message"

# WARN Message
2024-08-23 WARN (60103) "This is a Warning Message"

# ERROR Message
2024-08-23 ERROR (60103)
["Error","I messed up Something","Error: I messed up Something\n    at Object.<anonymous> l4js/test/index.js:14:14)\n    at Module._compile (node:internal/modules/cjs/loader:1358:14)\n    at Module._extensions..js (node:internal/modules/cjs/loader:1416:10)\n    at Module.load (node:internal/modules/cjs/loader:1208:32)\n    at Module._load (node:internal/modules/cjs/loader:1024:12)\n    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:174:12)\n    at node:internal/main/run_main_module:28:49"]

# DEBUG Message
2024-08-23 DEBUG (60103) "This is a Debug Message, In some app.. What is going on? "

Options

There are couple of options you can provide when you instantiate a l4js instance

name	description
dateFormat	A Date Format Default is "yyyy-MM-dd"
filePath	The File path where the log file file should be placed if logging to file is enabled
logLevel	The Log Level Default is * (Supports All Levels). you can choose info
logToFile	boolean flag to enable or disable logging to a file default is false
fileName	Your desired log filename if logging to file is enabled Default is "l4js.yyyy-MM-dd.log"
batchSize	Log Queue Batch size (default is 0)
flushInterval	The Log Queue flush interval to clear and write logs from a log queue

File Writes

Writing logs to file is a common use case with l4js it very easy to start logging your precious content to a file.

whenever you instantiate or create a new l4js object make sure you set the logToFile alway to true if you would like to log content to a given file.

l4js can either name the name file for you by using the default log file name l4js.yyyy-MM-dd.log or you van choose another name by providing your custom file name to with fileName parameter!

l4js provides 2 file Logging Strategies

• Write the Log immediately to file with every info(), warn(), error(), debug() invocation
• Store Logs in a Log Queue with a predefined size allocated once it exceed the the predefined size batchSize the queue is Flushed and written to log file.
• Flush the Queue at intervals flushInterval sometime its nice to not worry about anything if you provide a flushInterval (A interval in milliseconds) l4js will periodically check the LogQueue and flush it writing all Queue content to the given file.

Donations Welcome

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