The lazySizes bgset extension allows you to define multiple background images with a width descriptor. The extension will then load the best image size for the current viewport and device (https://github.com/aFarkas/lazysizes/tree/gh-pages/plugins/bgset)
This check is aimed at discouraging the use of the lazySizes bgset plugin
👎 Examples of incorrect code for this check:
<!-- Reports use of "lazyload" class and "data-bgset" attribute -->
<script src="ls.bgset.min.js"></script>
<script src="lazysizes.min.js"></script>
<div class="lazyload" data-bgset="image-200.jpg 200w, image-300.jpg 300w, image-400.jpg 400w" data-sizes="auto">
</div>
👍 Examples of correct code for this check:
<!-- Uses the CSS image-set() attribute instead of "data-bgset" -->
<!-- CSS Stylesheet -->
.box {
background-image: -webkit-image-set(
url("small-balloons.jpg") 1x,
url("large-balloons.jpg") 2x);
background-image: image-set(
url("small-balloons.jpg") 1x,
url("large-balloons.jpg") 2x);
}
<!-- HTML -->
<div class="box"></div>
The default configuration for this check is the following:
DeprecateBgsizes:
enabled: true
You should disable this rule in older browsers that don't support the CSS image-set attribute.
This check has been introduced in Theme Check 1.0.0.