Pendulum

A simple recurring task scheduler.

!npm (scoped)

``bash
npm install @hypericon/pendulum
`

Quickstart

`typescript
import { Pendulum, PendulumTask } from "@hypericon/pendulum";

const scheduler = new Pendulum();

const task: PendulumTask = {
label: "My task",
dueTime: Date.now() + 5_000, // 5 seconds in the future
taskFn: () => {
console.log("My task has been executed!");
},
};

scheduler.scheduleTask(task);
scheduler.start();

// 5 seconds later...
// [console]: "My task has been executed!"

const recurringTask: PendulumTask = {
label: "My recurring task",
dueTime: 0, // set to zero to calculate automatically for recurring tasks
rrule: {
freq: RRule.SECONDLY,
interval: 2,
},
taskFn: () => {
console.log("My recurring task has been executed!");
},
};
scheduler.scheduleTask(recurringTask);

// [console every 2 seconds]: "My recurring task has been executed!"

const taskWithCustomRecurrence: PendulumTask = {
label: "Another recurring task",
dueTime: 0,
recurrence: {
getDescription() => on the hour,
// Return a Date when the task will next become due after the parameter
findNext: (after: Date) => {
// If the task is being checked on the hour, execute it now
if (after.getMinutes() === 0 && after.getSeconds() === 0) {
return after;
}
// Calculate when the next hour will start
const d = new Date(after);
d.setHours(after.getHours() + 1);
d.setMinutes(0);
d.setSeconds(0);
return d;
},
},
taskFn: () => {
console.log("My recurring task has been executed!");
},
};
scheduler.scheduleTask(taskWithCustomRecurrence);

// [console on the hour]: "My recurring task has been executed!"

scheduler.stop();
``