Timer

A better solution for timeout- and interval-based timers.

Installation

Timer is available on npm as @oscarpalmer/timer to be bundled with your awesome projects.

Getting started

This is fairly lightweight package, so hopefully you'll be up and running in seconds 😊

Examples

The timers can be called with nice helper methods, which also auto-starts the timers:

import {repeat, wait} from '@oscarpalmer/timer';

const waited = wait(waitedCallback);
const repeated = repeat(repeatedCallback, 10);

Or they can be created using the new-keyword, but without being auto-started:

import {Timer} from '@oscarpalmer/timer';

const waited = new Timer(waitedCallback);
const repeated = new Timer(repeatedCallback, 10);

Parameters

When creating a Timer, either with the new new-keyword or using the functions, you can configure the timer with a few parameters:

Parameter	Description
callback	Callback function to be invoked for each run that are required for all timers. For more information on callbacks, please read the callbacks section.
count	How many times the timer should run. If no value is provided, it will default to 1 when using the new-keyword and the wait-method, but throws an error for the repeat-method.
time	How many milliseconds between each invokations of the provided callback. Defaults to 0, which is not really 0 milliseconds, but close enough 😉
after	A callback to run after the timer finishes, both when cancelled and completed. If count is greater than 1 and after is not undefined, a function is expected.

Methods and properties

An instance of Timer also has a few helpful methods and properties:

Name	Type	Description
active	Property	A boolean value to check if the timer is running
finished	Property	A boolean value to check if the timer was able to finish
start()	Method	Starts the timer. Necessary when creating a timer using the class syntax (e.g. new Waited...), but helpful when the timer needs to be started at other times, as well.
stop()	Method	Stops the timer
restart()	Method	Restarts the timer

Callbacks

Callbacks for both waited and repeated timers receive one parameter:

function callback(index) {
	// 'index' is the current step
	// starts at 0, goes up to a maximum of count - 1
	// for this example: 0 → 9
};

When you create a repeated timer, you can also provide a callback to run when the timer stops, as below:

function after(finished: boolean) {
	// Let's do something fun!
}

repeat(() => {}, 10, after);

The finished-parameter for the after-function can be used to determine if the timer was stopped manually, or if it was able to finish its work.

License

MIT licensed, natch 😉