taskman.js

CRON-scheduled asynchronous task manager.

The task manager ensures that a task's callback (even if asynchronous) will not run more than 1 execution concurrently.

Installation

npm i @nottimtam/taskman.js

Usage

ES6

import TaskMan from "@nottimtam/taskman.js";

const taskManager = new TaskMan();

const task = () => console.log("Hello, world!"); // The callback to run.

taskManager.createTask("my-task", task).schedule("*/5 * * * *"); // Run the task every 5 minutes.

CJS

const { TaskManager } = require("@nottimtam/taskman.js");

const taskManager = new TaskManager();

const task = () => console.log("Hello, world!"); // The callback to run.

taskManager.createTask("my-task", task).schedule("*/5 * * * *"); // Run the task every 5 minutes.

Reference

Importing in CJS

const { TaskManager, Task } = require("@nottimtam/taskman.js");

Importing in ESM

import TaskManager, { Task } from "@nottimtam/taskman.js";

TaskManager

Description: Manages tasks to ensure they do not run in parallel.

Constructor

• constructor()
  • Initializes an empty task manager.

Properties

• tasks: An object that stores tasks by their identifier.

Methods

• createTask(identifier, callback)
  • Creates a new task with the provided identifier and callback function.
  • identifier: The unique identifier for the task.
  • callback: The asynchronous function associated with the task.
  • Returns: The newly created Task instance.

Task

Description: Represents a task with a unique identifier and a callback function. It can be initiated manually or scheduled using a cron job.

While tasks can be created and run independently of a task manager, creating them using a TaskManager's createTask method will keep your tasks housed in one container.

Constructor

• constructor(identifier, callback)
  • identifier: A unique identifier for the task (string).
  • callback: The function to be executed when the task is initiated (function).

Properties

• identifier: The unique identifier for the task.
• callback: The function associated with the task.
• running: Boolean indicating whether the task is currently running.
• started: Timestamp indicating when the task was started.

Methods

• initiate()

  • Attempts to start the task. Logs a warning if the task is already running.
  • Returns: A Promise that resolves once the task is completed.

• schedule(time = "*/5 * * * *", timeZone = "default")

  • Schedules the task to run based on a cron schedule.
  • time: The cron time string (defaults to every five minutes).
  • timeZone: The timezone in which to operate the job (optional).
  • Returns: The newly created CronJob instance.