Accessible Mobile-friendly Image Lightbox Library – Parvus.js

Preview:

Description:

An accessible, touch-enabled, user-friendly image lightbox component written in plain JavaScript.

Features:

• Zoom in/out images on hover.
• Image loading indicator.
• Scroll or swipe to close just like Medium.com’s lightbox.
• Useful API methods and event handlers.
• Image counter.

How to use it:

1. You can also install & download the package with NPM.

# NPM
$ npm i react-spinners-css

2. Add references to Parvus JavaScript & CSS files.

<link rel="stylesheet" href="dist/css/parvus.min.css" />
<script src="dist/js/parvus.min.js"></script>

3. Create a new instance of the Parvus.js and pass the options as follows:

const prvs = new parvus({
  // All elements with this class triggers Parvus
  selector: '.lightbox',
  // All `selector` in this `gallerySelector` are combined as a gallery. Overwrites the `data-group` attribute
  gallerySelector: null,
  // Display captions, if available
  captions: true,
  // Set the element where the caption is. Set it to "self" for the `a` tag itself
  captionsSelector: 'self',
  // Get the caption from given attribute
  captionsAttribute: 'data-caption',
  // Click outside to close Parvus
  docClose: true,
  // Scroll to close Parvus
  scrollClose: false,
  // Swipe up/ down to close Parvus
  swipeClose: true,
  // Touch dragging threshold (in px)
  threshold: 100,
  // Set focus back to trigger element after closing Parvus
  backFocus: true,
  // Specifies how many milliseconds (ms) the transition effects takes to complete
  transitionDuration: 300,
  // Specifies the speed curve of the transition effects
  transitionTimingFunction: 'cubic-bezier(0.2, 0, 0.2, 1)',
  // Icons
  lightboxIndicatorIcon: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path d="M8 3H5a2 2 0 00-2 2v3m18 0V5a2 2 0 00-2-2h-3m0 18h3a2 2 0 002-2v-3M3 16v3a2 2 0 002 2h3"/></svg>',
  previousButtonIcon: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path stroke="none" d="M0 0h24v24H0z"/><polyline points="15 6 9 12 15 18" /></svg>',
  nextButtonIcon: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path stroke="none" d="M0 0h24v24H0z"/><polyline points="9 6 15 12 9 18" /></svg>',
  closeButtonIcon: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path d="M18 6L6 18M6 6l12 12"/></svg>',
  // Localization of strings
  l10n: en,
  // Regular expression for supported image file types
  fileTypes: /\.(png|jpe?g|webp|avif|svg)(\?.*)?$/i
});

4. Apply the image lightbox to an image element. That’s it.

<a href="full.jpg" class="image-lightbox" data-caption="Caption Here">
  <img src="thumb.jpg" alt="Image Alt" />
</a>

imageSelector = document.querySelector('.image-lightbox');
prvs.add(imageSelector);

6. Create a gallery lightbox by grouping your images using the ‘data-group’ attribute or ‘gallerySelector’ option.

<a href="1.jpg" class="lightbox" data-group="Berlin">
  <img src="1.jpg" alt="">
</a>
<a href="2.jpg" class="lightbox" data-group="Berlin">
  <img src="2.jpg" alt="">
</a>
<a href="3.jpg" class="lightbox" data-group="Kassel">
  <img src="3.jpg" alt="">
</a>

7. More API methods.

// add an image element
prvs.add(element);

// remove an image element
prvs.remove(element);

// open the lightbox
prvs.open(el);

// close the lightbox
prvs.close();

// destroy the instance
prvs.destroy(destroy);

// check if is open
prvs.isOpen();

// get the current index
prvs.currentIndex();

// go to the prev image
prvs.previous();

// go to the next image
prvs.next();

// select a slide
prvs.select(index);

6. Bind/unbind event listeners.

// prvs.on(eventName, listener)
// prvs.off(eventName, listener)
prvs.on('open', listener);
prvs.on('close', listener);
prvs.on('select', listener);
prvs.on('destroy', listener);

Changelog:

v2.0.4 (01/21/2022)

• Add aria-labelledby for slides with captions
• Improvements
• Clean up

v2.0.3 (01/19/2022)

• Fix issue when loading an image for the first time
• Improvements

v2.0.2 (01/19/2022)

• Use box-sizing: border-box
• Fix issue with duplicate slides

v2.0.1 (01/18/2022)

• Fix issue with slides without caption
• Fix new “reset groups” disaster

v2.0.0 (01/18/2022)

• Update dev dependencies
• Remove own focus style
• Add more options for captions
• Breaking change Refactor localization
• Add toolbar container for future functions
• Fix: Add function to calculate image

v1.4.1 (09/30/2021)

• Update dev dependencies