setIdle()

Monitors your JS application for when the user is idle and triggers events.

var idle = setIdle(() => doSomething('awesome'));

Installation

NPM

> npm install setidle

Bower

> bower install setidle

The old-fashioned way

<script type="text/javascript" src="setidle.js"></script>

Background

Does your JavaScript front-end send back telemetry or do other activities that aren't time sensitive? If so, then a simple way to improve the performance of your application is to queue up those requests until the application is "idle", for example if a user is reading something and not causing the UI to process anything. This can help to ensure that your complex interactions remain smooth, and that you're only running code when you absolutely have the resources to do so, especially on mobile.

[Giphy]

Features

• Simple no-nonsense browser implementation based on window.setTimeout.
• Class constructor which wraps event emitters with reasonable duck-typing support.
• Can be configured to work on a specific HTML element or the entire document.

Examples

CommonJS/Node

var SetIdle = require('setidle');
var idle = new SetIdle(emitter);
idle.start(() => doSomething('awesome'));

RequireJS

require(['setidle'], function (SetIdle) {
    var idle = new SetIdle(emitter);
    idle.start(() => doSomething('awesome'));
});

Browser

var element = document.getElementById('panelStuff');
var idle = new SetIdle(new SetIdle.DOMEventEmitter(element));
idle.start(() => doSomething('awesome'));

Usage

SetIdle (emitter)

• Constructs an idle monitor.
• The SetIdle constructor expects a single parameter emitter, which has either an on() or addListener() method, and an off() or removeListener() method.
• It is compatible with the NodeJS EventEmitter class in the events API.

SetIdle.start (fnIdle, [fnActive], [config])

• Starts monitoring of the given event emitter.
• The fnIdle callback will be triggered when the application is idle.
• The fnActive callback will be triggered when the application is active again.
• The config object is expected to take the following form. These are defaults if no config is provided:

    {
        /**
         * How long to wait for event silence before declaring the application as idle.
         */
        interval: 3000,

        /**
         * A list of events to use in order to determine when the system is in use.
         */
        events: [

            // The user is interacting with the page.
            'change',
            'click',
            'dblclick',
            'scroll',
            'touchstart',
            'touchend',

            // watch for indications that the browser is having to re-paint the page.
            'resize',
            'mutated' // this is a virtual event, we're using MutationObserver under the hood.
        ]
    }

SetIdle.stop()

• Stops all monitoring activity.

window.setIdle (fnIdle, [fnActive], [interval])

• Modeled after window.setTimeout
• The fnIdle callback will be triggered when the application is idle.
• The fnActive callback will be triggered when the application is active again.
• The interval defines how many milliseconds of inactivity constitutes "idleness". The default is 3000 milliseconds.
• Note that the procedural version automatically passes window.document to the DOMEventEmitter constructor.
• Returns an instance of the SetIdle object used to start monitoring.

window.clearIdle (idle)

• Modeled after window.clearTimeout
• Stops the given SetIdle instance by calling the SetIdle.stop method.

Contributing

Contributions and pull requests are welcome! If you see a feature that you want, add it to our issue tracker. If you find a bug, definitely report back to us.