Logger

Logger is a logging library for handling log messages and notifying logger targets.

Features

• Logging messages to multiple targets
• Customizable logger targets
• Flexible payload structure

Installation

npm install @workehub/logger

Usage

1. Import the necessary classes and interfaces from the @workehub/logger package:

import { LoggerObserver, LoggerPayload } from "@workehub/logger";

2. Create a class that implements the LoggerObserver interface to define a logger target. For example, here's an implementation using Kafka as the target:

class KafkaLog implements LoggerObserver {
  private kafka: any; // Import the correct Kafka library here

  constructor() {
    // Initialize the connection to Kafka
    this.kafka = /* Initialize the connection to Kafka */;
  }

  update(payload: LoggerPayload): void {
    // Send the log message to the Kafka queue
    this.kafka.sendMessage(payload);
  }
}

3. Use the static methods of the Logger class to manage logger targets:

// Create instances of the logger targets you want to use
const consoleLog = new ConsoleLog(); // Example using ConsoleLog
const kafkaLog = new KafkaLog(); // Example using KafkaLog

// Attach the logger observers using static methods of the Logger class
Logger.attach("console", consoleLog);
Logger.attach("kafka", kafkaLog);

4. Use the notify method to send log messages to the registered logger targets:

// Create an example log payload
const payload: LoggerPayload = {
  level: "event",
  message: "New event created",
  additionalInfo: {
    event: "Birthday Party",
    date: "2023-07-20",
    location: "City Park",
  },
  timestamp: Date.now(),
};

// Notify the logger to send the payload to the registered logger targets
Logger.notify(["console", "kafka"], payload);

Note

The ConsoleLog target is included by default and does not need to be explicitly registered. You can simply call Logger.notify(["console"], payload) to log messages to the console.

Screenshots

API

static notify(types: string[], payload: LoggerPayload): void

Notifies the specified logger targets with the log data.

• types: An array of target types to notify.
• payload: The log data object with the following properties:
  • level: The log level, e.g., 'error', 'info', 'debug'.
  • message: The log message.
  • additionalInfo (optional): Additional information to include in the log.

static attach(type: string, observer: LoggerObserver): void

Registers a logger target with the specified type.

• type: The type name for the logger target.
• observer: An instance of a logger target implementation.