Event-Schedule.js - A timeline scheduler

This module allows you to define a timeline comprising events with start and end time, and have s user-supplied function called when an event is scheduled to start or end. If an event is already scheduled to be in progress, your function will be called in a way indicating that.

Quick start

• Setup an array of events:

const events = [
    { startTime: '2020-08-20T10:00:00Z' },
    { startTime: '2020-08-20T14:00:00Z' },
    { startTime: '2020-08-20T11:00:00Z' },
];

• Define your handler function

const handleEvent = (state, event) => {
    console.log('State', state, 'signaled for event:', JSON.stringify(event));
};

The function should be able to handle the following state values:

• start: The event is starting now.
• inProgress: The event has already started, and hasn't ended. No event with a later start is in the schedule.
• end: The event end time has arrived
• past: The time of this event has passed. There will no no further callbacks for it.

For Typescript the possible values are defined in the type EventState.

• Get your events scheduled. Your handler will be called at least once for each event, as its state changes.

const es = new ScheduledEventTimeline(events, handleEvent);
es.start();

Details

Event specification format

The events must include startTime, and may optionally include endTime. The following formats may be used:

• ISO 8601 timestamp including offset from UTC. E.g.: 2020-08-20T11:00:00Z, 2020-08-25T11:00:00+02
• Numeric timestamp in the format returned by Date.now() (milliseconds from the epoch).
• Relative time as hh:mm:ss or hh:mm.

ISO 8601 and numeric timestamps are always interpreted as points in time. Relative timestamps are interpreted a little differently for start and end times. For start times, they're assumed to be relative to the time the start() method is called. For end times, they're interpreted as relative to the start time.

Typescript

This library is written in Typescript and hence provides full type definitions. You're encouraged to look at the exported type and method definitions.