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Jarallax

jarallax.min.js jarallax-video.min.js

Parallax scrolling for modern browsers. Supported <img> tags, background images, YouTube, Vimeo and Self-Hosted Videos.

Online Demo

Table of Contents

WordPress Plugin

Advanced WordPress Backgrounds

We made WordPress plugin to easily add backgrounds for content in your blog with all Jarallax features.

Demo: https://wpbackgrounds.com/

Download: https://wordpress.org/plugins/advanced-backgrounds/

Quick Start

There are a set of examples, which you can use as a starting point with Jarallax.

Import Jarallax

Use one of the following examples to import jarallax.

ESM

We provide a version of Jarallax built as ESM (jarallax.esm.js and jarallax.esm.min.js) which allows you to use Jarallax as a module in your browser, if your targeted browsers support it.

<script type="module">
  import { jarallax, jarallaxVideo } from "jarallax.esm.min.js";

  // Optional video extension
  jarallaxVideo();
</script>

ESM CDN

<script type="module">
  import { jarallax, jarallaxVideo } from "https://cdn.jsdelivr.net/npm/jarallax@2/+esm";

  // Optional video extension
  jarallaxVideo();
</script>

UMD

Jarallax may be also used in a traditional way by including script in HTML and using library by accessing window.jarallax.

<script src="jarallax.min.js"></script>

<!-- Optional video extension -->
<script src="jarallax-video.min.js"></script>

UMD CDN

<script src="https://cdn.jsdelivr.net/npm/jarallax@2/dist/jarallax.min.js"></script>

<!-- Optional video extension -->
<script src="https://cdn.jsdelivr.net/npm/jarallax@2/dist/jarallax-video.min.js"></script>

CJS (Bundlers like Webpack)

Install Jarallax as a Node.js module using npm

npm install jarallax

Import Jarallax by adding this line to your app's entry point (usually index.js or app.js):

import { jarallax, jarallaxVideo } from "jarallax";

// Optional video extension
jarallaxVideo();

Add styles

These styles required to set proper background image position before Jarallax script initialized:

.jarallax {
  position: relative;
  z-index: 0;
}
.jarallax > .jarallax-img {
  position: absolute;
  object-fit: cover;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
}

You can include it from /dist/jarallax.css.

Prepare HTML

<!-- Background Image Parallax -->
<div class="jarallax">
  <img class="jarallax-img" src="<background_image_url_here>" alt="">
  Your content here...
</div>

<!-- Background Image Parallax with <picture> tag -->
<div class="jarallax">
  <picture class="jarallax-img">
    <source media="..." srcset="<alternative_background_image_url_here>">
    <img src="<background_image_url_here>" alt="">
  </picture>
  Your content here...
</div>

<!-- Alternate: Background Image Parallax -->
<div class="jarallax" style="background-image: url('<background_image_url_here>');">
  Your content here...
</div>

Run Jarallax

Note: automatic data-attribute initialization and jQuery integration are available in UMD mode only.

A. JavaScript way

jarallax(document.querySelectorAll('.jarallax'), {
  speed: 0.2,
});

B. Data attribute way

<div data-jarallax data-speed="0.2" class="jarallax">
  <img class="jarallax-img" src="<background_image_url_here>" alt="">
  Your content here...
</div>

Note: You can use all available options as data attributes. For example: data-speed, data-img-src, data-img-size, etc...

C. jQuery way

$('.jarallax').jarallax({
  speed: 0.2,
});

No conflict (only if you use jQuery)

Sometimes to prevent existing namespace collisions you may call .noConflict on the script to revert the value of.

const jarallaxPlugin = $.fn.jarallax.noConflict() // return $.fn.jarallax to previously assigned value
$.fn.newJarallax = jarallaxPlugin // give $().newJarallax the Jarallax functionality

Background Video Usage Examples

A. JavaScript way

import { jarallax, jarallaxVideo } from 'jarallax';
jarallaxVideo();

jarallax(document.querySelectorAll('.jarallax'), {
  speed: 0.2,
  videoSrc: 'https://www.youtube.com/watch?v=ab0TSkLe-E0'
});
<div class="jarallax"></div>

B. Data attribute way

<!-- Background YouTube Parallax -->
<div class="jarallax" data-jarallax data-video-src="https://www.youtube.com/watch?v=ab0TSkLe-E0">
  Your content here...
</div>

<!-- Background Vimeo Parallax -->
<div class="jarallax" data-jarallax data-video-src="https://vimeo.com/110138539">
  Your content here...
</div>

<!-- Background Self-Hosted Video Parallax -->
<div class="jarallax" data-jarallax data-video-src="mp4:./video/local-video.mp4,webm:./video/local-video.webm,ogv:./video/local-video.ogv">
  Your content here...
</div>

Note: self-hosted videos require 1 video type only, not necessarily using all mp4, webm, and ogv. This is only needed for maximum compatibility with all browsers.

Options

Options can be passed in data attributes or in object when you initialize jarallax from script.

Name Type Default Description
type string scroll scroll, scale, opacity, scroll-opacity, scale-opacity.
speed float 0.5 Parallax effect speed. Provide numbers from -1.0 to 2.0.
imgSrc path null Image url. By default used image from background.
imgElement dom / selector .jarallax-img Image tag that will be used as background.
imgSize string cover Image size. If you use <img> tag for background, you should add object-fit values, else use background-size values.
imgPosition string 50% 50% Image position. If you use <img> tag for background, you should add object-position values, else use background-position values.
imgRepeat string no-repeat Image repeat. Supported only background-position values.
keepImg boolean false Keep <img> tag in it's default place after Jarallax inited.
elementInViewport dom null Use custom DOM / jQuery element to check if parallax block in viewport. More info here - Issue 13.
zIndex number -100 z-index of parallax container.
disableParallax RegExp / function - Disable parallax on specific user agents (using regular expression) or with function return value. The image will be set on the background.
disableVideo RegExp / function - Disable video load on specific user agents (using regular expression) or with function return value. The image will be set on the background.

Disable on mobile devices

You can disable parallax effect and/or video background on mobile devices using option disableParallax and/or disableVideo.

Example:

jarallax(document.querySelectorAll('.jarallax'), {
  disableParallax: /iPad|iPhone|iPod|Android/,
  disableVideo: /iPad|iPhone|iPod|Android/
});

Or using function. Example:

jarallax(document.querySelectorAll('.jarallax'), {
  disableParallax: function () {
    return /iPad|iPhone|iPod|Android/.test(navigator.userAgent);
  },
  disableVideo: function () {
    return /iPad|iPhone|iPod|Android/.test(navigator.userAgent);
  }
});

Additional options for video extension

Required jarallax/jarallax-video.js file.

Name Type Default Description
videoSrc string null You can use Youtube, Vimeo or Self-Hosted videos. Also you can use data attribute data-jarallax-video.
videoStartTime float 0 Start time in seconds when video will be started (this value will be applied also after loop).
videoEndTime float 0 End time in seconds when video will be ended.
videoLoop boolean true Loop video to play infinitely.
videoPlayOnlyVisible boolean true Play video only when it is visible on the screen.
videoLazyLoading boolean true Preload videos only when it is visible on the screen.

Events

Events used the same way as Options.

Name Description
onScroll Called when parallax working. Use first argument with calculations. More info see below.
onInit Called after init end.
onDestroy Called after destroy.
onCoverImage Called after cover image.

Additional events for video extension

Required jarallax/jarallax-video.js file.

Name Description
onVideoInsert Called right after video is inserted in the parallax block. Video can be accessed by this.$video
onVideoWorkerInit Called after VideoWorker script initialized. Available parameter with videoWorkerObject.

onScroll event

jarallax(document.querySelectorAll('.jarallax'), {
  onScroll: function(calculations) {
    console.log(calculations);
  }
});

Console Result:

{
  // parallax section client rect (top, left, width, height)
  rect            : object,

  // see image below for more info
  beforeTop       : float,
  beforeTopEnd    : float,
  afterTop        : float,
  beforeBottom    : float,
  beforeBottomEnd : float,
  afterBottom     : float,

  // percent of visible part of section (from 0 to 1)
  visiblePercent  : float,

  // percent of block position relative to center of viewport from -1 to 1
  fromViewportCenter: float
}

Calculations example: On Scroll Calculations

Methods

Name Result Description
destroy - Destroy Jarallax and set block as it was before plugin init.
isVisible boolean Check if parallax block is in viewport.
onResize - Fit image and clip parallax container. Called on window resize and load.
onScroll - Calculate parallax image position. Called on window scroll.

Call methods example

A. JavaScript way

jarallax(document.querySelectorAll('.jarallax'), 'destroy');

B. jQuery way

$('.jarallax').jarallax('destroy');

For Developers

Installation

  • Run npm install in the command line

Building

  • npm run dev to run build and start local server with files watcher
  • npm run build to run build

Linting

  • npm run js-lint to show eslint errors
  • npm run js-lint-fix to automatically fix some of the eslint errors

Test

  • npm run test to run unit tests

Real Usage Examples

Credits