Theme.json: enable block-level background image styles

[ramonopoly]

A ticket to track the Gutenberg PR sync for enabling enable block-level background image styles in theme.json

The merged Gutenberg PR: ​https://github.com/WordPress/gutenberg/pull/60100

Work in progress...

Syncing source code changes from WordPress/gutenberg#60100

Trac ticket: https://core.trac.wordpress.org/ticket/61588>

Thanks for adding the @ticket comments, missed those in my review, sorry.

Latest changes LGTM 🚀

I appreciate the quick review!

[noisysocks]

@ramonopoly: OK to commit this? (Happy to guide you through it. DM me.)

[ramonopoly]

@noisysocks Thanks for the ping. Yes, a walkthrough would be appreciated!

[noisysocks]

In 58797:

Block themes: Enable block-level background image styles

Allows defining background images for blocks in theme.json.

Syncs PHP changes from ​https://github.com/WordPress/gutenberg/pull/60100.

Props ramonopoly, aaronrobertshaw.
Fixes #61588.

Committed in r58797.

@ramonjd @joemcgill @felixarntz

I ran local Server-Timing benchmarks with and without these PR changes and found that the PR is responsible for ~3% regression.

### Server-Timing benchmarks

Mertic	Beta 3	Beta 3 without these PR changes	Diff %	Diff abs.
Response Time	69.05	65.67	-4.90%	-3.38
wp-before-template	30.94	29.67	-4.10%	-1.27
wp-template	35.45	34.15	-3.67%	-1.30
wp-total	66.87	63.97	-4.34%	-2.90

I ran local Server-Timing benchmarks with and without these PR changes and found that the PR is responsible for ~3% regression.

Interesting. Thanks for the ping!

I'm at the end of my day, but I wonder if the following needs to be cached:

​https://github.com/WordPress/wordpress-develop/pull/6836/files#diff-1be8a8089d87d1b4b6e449c0967680d6f7c170d13f247180a975cbea5e54070fR310

@mukeshpanchal27 Are you comparing against local changes using ​https://github.com/mukeshpanchal27/compare-wp-performance? Could you share your workflow? Thanks!

@mukeshpanchal27 Are you comparing against local changes using ​https://github.com/mukeshpanchal27/compare-wp-performance? Could you share your workflow? Thanks!

See ​https://make.wordpress.org/performance/handbook/measuring-performance/benchmarking-php-performance-with-server-timing/

@ramonjd @mukeshpanchal27

I'm at the end of my day, but I wonder if the following needs to be cached:

​https://github.com/WordPress/wordpress-develop/pull/6836/files#diff-1be8a8089d87d1b4b6e449c0967680d6f7c170d13f247180a975cbea5e54070fR310

Good suggestion. Let's first verify that that method is indeed responsible for a notable performance decline. Maybe just comment it out and rerun the benchmarks to compare?

Let's first verify that that method is indeed responsible for a notable performance decline. Maybe just comment it out and rerun the benchmarks to compare?

Commented over here: ​https://github.com/WordPress/performance/issues/1572#issuecomment-2415698594

I'm not sure there's much to see here yet.

I also mentioned that I think there needs to be a caching strategy for resolved URIs however:

I think perhaps caching them in WP_Theme_JSON_Resolver as is done with theme_json might work, using get_stylesheet() or get_stylesheet_directory() as a key. I'll add it to my list of things to look into.

Thank you!