Query to assess lazy-loading of LCP image

[felixarntz]

• Create HTTP Archive query to get % of WordPress sites that use loading="lazy" on LCP image
  • Relate it with query from Query to assess usage of fetchpriority="high" on LCP image #5 for % of WordPress sites that even have an image as the LCP element
• Create HTTP Archive query to get % of WordPress sites that are on version >= 5.5 and have at least one image with loading="lazy"

[felixarntz]

cc @vishalkakadiya @pushpakpop

[felixarntz]

Also see related #9 and #10

[vishalkakadiya]

@felixarntz For the second point here, we can take some reference to the query below. What do you say?

Create HTTP Archive query to get % of WordPress sites that are on version >= 5.5 and have at least one image with loading="lazy"

https://discuss.httparchive.org/t/lazy-loaded-lcp-images-by-wordpress-version/2455/2

[felixarntz]

Thanks @vishalkakadiya, that's super useful. It actually helps with both questions. I came up with a query based on it that addresses both points. The first part is the most important one anyway.

See #28, ready for your review :)

[kt-12]

@felixarntz do we need to address the second point?
Create HTTP Archive query to get % of WordPress sites on version >= 5.5 and have at least one image with loading="lazy".

I see your query works on the LCP element only, and In the second point, we need to find at least one image with loding="lazy" across the entire page. This can be obtained from _markup which contains JSON that has images.img.loading.lazy that gives the direct count of lazy loaded images on a page.

[vishalkakadiya]

@kt-12 Thank you for pointing this out.

In my opinion, I think any one image with the loading="lazy" query is not needed as this epic is for improving the lazy-loading feature to overcome the LCP image issue with the lazy-loading feature.

CC @felixarntz

[felixarntz]

@kt-12 Good catch! I should have explained my thinking in the PR, basically I agree with @vishalkakadiya that I don't think we really need this piece of information. I think having the overall number of sites on WP version >= 5.5 is accurate enough, as lazy-loading is enabled by default and it would require a filter to disable it, which is extremely unlikely to be used when looking at scale.