task

Scheduled tasks with Mongoose

Getting Started

Requires Node >= 14 and Mongoose >= 6.7.0

``javascript
const mongoose = require('mongoose');

// Task is a Mongoose model that has several helpful methods and statics
// for working with scheduled tasks.
const Task = require('@mongoosejs/task')();

// Register a handler for a named task and start polling for sayHello tasks
Task.registerHandler('sayHello', function sayHello() {
console.log('Hello, World!');
});
Task.startPolling();

// Will print 'Hello, World!' after approximately 1 second
await Task.schedule('sayHello', new Date(Date.now() + 1000));
`

Polling Options

You can pass getCurrentTime() to startPolling() to supply a custom clock for polling,
which is useful for demos or tests that advance time automatically.

`javascript
let currentTime = new Date('2023-06-01T00:00:00.000Z');

Task.startPolling({
getCurrentTime: () => new Date(currentTime)
});

currentTime = new Date(currentTime.valueOf() + 60_000);
`

Params

The 2nd param to Task.schedule() is an object that this framework will call the handler function with.

`javascript
Task.registerHandler('sayHello', function sayHello(params) {
console.log(Hello, ${params.name}!);
});

// Will print 'Hello, Friend!' after approximately 1 second
await Task.schedule(
'sayHello',
new Date(Date.now() + 1000),
{ name: 'Friend' }
);
`

Repeating Tasks

The 3rd param to Task.schedule() is called repeatAfterMS.
If repeatAfterMS is set, this framework will immediately reschedule the task to run after repeatAfterMS once the original task is done.

`javascript
Task.registerHandler('sayHello', function sayHello(params) {
console.log(Hello, ${params.name}!);
});

// Will print 'Hello, Friend!' every 5 seconds, after a 1 second
// initial delay
await Task.schedule(
'sayHello',
new Date(Date.now() + 1000),
{ name: 'Friend' },
5000
);
``