Bug 231894

Summary:	Allow for different lazy loading policies on responsive image sources.
Product:	WebKit	Reporter:	Patrick Meenan <patmeenan>
Component:	Images	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Enhancement	CC:	nmouchtaris, rbuis, sabouhallawa, simon.fraser, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	All
OS:	All

Description Patrick Meenan 2021-10-18 08:27:42 PDT

Currently lazy loading is applied to the <img> element, even when there are multiple <source> tags for the same image within a <picture>.

For a responsive site that may have different images in the viewport based on layout (mobile vertical scroll vs desktop grid for example), a developer will need to decide which layout to optimize for and potentially slow down the performance of the other layouts.

A possible solution would be to have a given <source> to have a loading attribute that would override the lazy loading state of the <img> that it is associated with.

This is an extension of the original lazyload support: https://bugs.webkit.org/show_bug.cgi?id=200764

whatwg issue: https://github.com/whatwg/html/issues/7227

Comment 1 Radar WebKit Bug Importer 2021-10-25 08:28:40 PDT

<rdar://problem/84615291>