lekoala/silverstripe-lazysizes

Adds lazysizes in the SilverStripe CMS

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Type:silverstripe-module

dev-master 2021-09-02 12:52 UTC

This package is auto-updated.

Last update: 2022-04-30 14:09:27 UTC


README

Integrate https://github.com/aFarkas/lazysizes and https://github.com/aFarkas/respimage to Silverstripe.

Code heavily inspired by https://github.com/heyday/silverstripe-responsive-images

All-in-one solution for:

  • Lazy loading images
  • Responsive images
  • Placeholder images (using placehold.it)

Respimages is only loaded if the browser does not support native syntax.

Plugins

This modules has already pre built plugins into a consolidated js file.

Plugins available by default are:

Lasysizes:

  • unveilhooks
  • print
  • bgset
  • include

Respimages:

  • oldie
  • intrinsic
  • mutation

You can also define your own path to the libraries by adjusting the following path

LazySizesImageExtension:
	js_path: 'lazysizes/javascript'

LazyLoading

If you simply want to lazy load your image, you can use any of three default methods which specify no additional sizes.

Example:

$Image.Lazy(720x250)
$Image.LazyCrop(720x250)
$Image.LazyCropFocus(720x250)

Responsive sets

You can define your own responsive sets. You can see the bundled configuration for the ResponsiveDefault set which set 4 breakpoints. You can define your own sets, change sizes, method and default size to be used.

All sets use lazysizes data-sizes="auto" by default, meaning that the width of the parent is used to determine which size needs to be loaded.

Retina is also supported.

Config example:

LazySizesImageExtension:
	ResponsiveDefault:
		sizes: [320x213 320w,640x426 640w,960x639 960w,1280x852 1280w]
	ResponsiveDefaultSquare:
		sizes: [320x320 320w,640x640 640w,960x960 960w,1280x1280 1280w]
	ResponsiveDefaultRetina:
		sizes: [400x300 1x, 800x600 2x]

Usage example in template:

$Image.ResponsiveDefault

Using placeholders

The controller extension provides a helper method to easily create placeholders using PlaceholdIt. You can define a base size and a src set.

Example:

$PlaceholdIt(175x75,'200x100,500x300,800x400')

SrcSet

Sometimes, you just need to output a list of srcset paths (for instance, to define a bgset). The last element of the set is never resized (always using the original image at maximum size). You can prevent this from happening by setting the second argument to false.

Example:

<body id="$ClassName" class="typography lazyload" data-bgset="$SiteConfig.RandomBackgroundImage.SrcSet('480,800')">

Compatibility

Tested with 3.1

Installation

composer require lekoala/silverstripe-lazysizes

Maintainer

LeKoala - thomas@lekoala.be