fastclick README

The project's README from github.com/ftlabs/fastclick. As one markdown file: README.md.

FastClick

FastClick is a simple, easy-to-use library for eliminating the 300ms delay between a physical tap and the firing of a click event on mobile browsers. The aim is to make your application feel less laggy and more responsive while avoiding any interference with your current logic.

FastClick is developed by FT Labs, part of the Financial Times.

Note: As of late 2015 most mobile browsers - notably Chrome and Safari - no longer have a 300ms touch delay, so fastclick offers no benefit on newer browsers, and risks introducing bugs into your application. Consider carefully whether you really need to use it.

Explication en français.

日本語で説明。

Why does the delay exist?

According to Google:

...mobile browsers will wait approximately 300ms from the time that you tap the button to fire the click event. The reason for this is that the browser is waiting to see if you are actually performing a double tap.

Compatibility

The library has been deployed as part of the FT Web App and is tried and tested on the following mobile browsers:

When it isn't needed

FastClick doesn't attach any listeners on desktop browsers.

Chrome 32+ on Android with width=device-width in the viewport meta tag doesn't have a 300ms delay, therefore listeners aren't attached.

<meta name="viewport" content="width=device-width, initial-scale=1">

Same goes for Chrome on Android (all versions) with user-scalable=no in the viewport meta tag. But be aware that user-scalable=no also disables pinch zooming, which may be an accessibility concern.

For IE11+, you can use touch-action: manipulation; to disable double-tap-to-zoom on certain elements (like links and buttons). For IE10 use -ms-touch-action: manipulation.

Usage

Include fastclick.js in your JavaScript bundle or add it to your HTML page like this:

<script type='application/javascript' src='/path/to/fastclick.js'></script>

The script must be loaded prior to instantiating FastClick on any element of the page.

To instantiate FastClick on the body, which is the recommended method of use:

if ('addEventListener' in document) {
	document.addEventListener('DOMContentLoaded', function() {
		FastClick.attach(document.body);
	}, false);
}

Or, if you're using jQuery:

$(function() {
	FastClick.attach(document.body);
});

If you're using Browserify or another CommonJS-style module system, the FastClick.attach function will be returned when you call require('fastclick'). As a result, the easiest way to use FastClick with these loaders is as follows:

var attachFastClick = require('fastclick');
attachFastClick(document.body);

Minified

Run make to build a minified version of FastClick using the Closure Compiler REST API. The minified file is saved to build/fastclick.min.js or you can download a pre-minified version.

Note: the pre-minified version is built using our build service which exposes the FastClick object through Origami.fastclick and will have the Browserify/CommonJS API (see above).

var attachFastClick = Origami.fastclick;
attachFastClick(document.body);

AMD

FastClick has AMD (Asynchronous Module Definition) support. This allows it to be lazy-loaded with an AMD loader, such as RequireJS. Note that when using the AMD style require, the full FastClick object will be returned, not FastClick.attach

var FastClick = require('fastclick');
FastClick.attach(document.body, options);

Package managers

You can install FastClick using Component, npm or Bower.

For Ruby, there's a third-party gem called fastclick-rails. For .NET there's a NuGet package.

Advanced

Ignore certain elements with needsclick

Sometimes you need FastClick to ignore certain elements. You can do this easily by adding the needsclick class.

<a class="needsclick">Ignored by FastClick</a>

Use case 1: non-synthetic click required

Internally, FastClick uses document.createEvent to fire a synthetic click event as soon as touchend is fired by the browser. It then suppresses the additional click event created by the browser after that. In some cases, the non-synthetic click event created by the browser is required, as described in the triggering focus example.

This is where the needsclick class comes in. Add the class to any element that requires a non-synthetic click.

Use case 2: Twitter Bootstrap 2.2.2 dropdowns

Another example of when to use the needsclick class is with dropdowns in Twitter Bootstrap 2.2.2. Bootstrap add its own touchstart listener for dropdowns, so you want to tell FastClick to ignore those. If you don't, touch devices will automatically close the dropdown as soon as it is clicked, because both FastClick and Bootstrap execute the synthetic click, one opens the dropdown, the second closes it immediately after.

<a class="dropdown-toggle needsclick" data-toggle="dropdown">Dropdown</a>

Examples

FastClick is designed to cope with many different browser oddities. Here are some examples to illustrate this:

Tests

There are no automated tests. The files in tests/ are manual reduced test cases. We've had a think about how best to test these cases, but they tend to be very browser/device specific and sometimes subjective which means it's not so trivial to test.

Credits and collaboration

FastClick is maintained by Rowan Beentje, Matthew Caruana Galizia and Matthew Andrews at FT Labs. All open source code released by FT Labs is licenced under the MIT licence. We welcome comments, feedback and suggestions. Please feel free to raise an issue or pull request.

fastclick (ftlabs/fastclick)

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18.5K ·GitHub
Fastclick
archived
What is this?A small open-source JavaScript library from FT Labs, part of the Financial Times. It removes the 300ms delay between a physical tap and the firing of the click event on mobile browsers, so apps feel less laggy and more responsive.
Is this something I add to my web page's code, or an app I install?A polyfill library: you include fastclick.js in your page or JavaScript bundle and it patches tap handling in the browser at runtime. Nothing is installed on the device itself.
How do I add it to my site?Install it with npm, Bower or Component, or just add fastclick.js to the page. Load the script first, then call FastClick.attach(document.body) - the recommended way to cover the whole page.
Do I need jQuery or any other libraries for it to work?No, plain JavaScript is enough. There is an optional jQuery shortcut, require('fastclick') returns FastClick.attach for CommonJS users, and AMD loaders like RequireJS get the full object instead.
Is this still worth using today?Mostly no: since late 2015 Chrome and Safari no longer have the 300ms delay, so on newer browsers FastClick adds nothing and risks introducing bugs. The repository has also been archived.
Which mobile browsers does it actually work on?It was tried and tested on Mobile Safari (iOS 3 and up), Chrome on iOS 5+, Chrome on Android (ICS), Opera Mobile 11.5+, the Android browser since Android 2 and PlayBook OS 1+, and it shipped in the FT Web App.
Why did mobile browsers have that 300ms delay in the first place?Browsers waited about 300ms after a tap before firing click, to check whether the user was starting a double-tap zoom. FastClick short-circuits that wait by firing a synthetic click the moment touchend happens.
How does it remove the delay technically?As soon as touchend fires it builds a synthetic click with document.createEvent, dispatches it immediately, and suppresses the browser's own follow-up click so one tap produces only one event.
What is the needsclick class for?Add it to elements FastClick should leave alone: inputs that need the browser's real click to trigger focus, or Twitter Bootstrap 2.2.2 dropdowns, which otherwise open and instantly close again on touch devices.
Does it do anything on desktop browsers?No, it attaches no listeners there. It also skips Chrome 32+ on Android when the viewport meta tag has width=device-width, and IE10/11 should use the CSS touch-action: manipulation instead.
What are similar projects?skrollr, better-scroll, Respond, lib-flexible, interact.js, swiper, Sortable, hammer.js
Which topics is it in?click, event, polyfill, mobile-web, touch, responsive, javascript-library, deprecated, browser, html, mobile, ios
Creator
ftlabs
Size
0.3 MB
Stars
18.5K
Updated
CommitFeb 12Releasev1.0.6Jan 26
Age
14y
Commits · 90 Days