Editor: Cache the theme.json data merged from all origins by sirreal · Pull Request #14071 · WordPress/wordpress-develop

sirreal · 2026-10-07T14:10:13Z

WP_Theme_JSON_Resolver::get_merged_data() repeats the same merges on every call, including once per block with an is-style-* class. Cache the merged data per origin for the request, and return a clone so callers can modify their copy.

Backport of WordPress/gutenberg#81979.

In Gutenberg on WordPress 7.2-alpha with WP_DEBUG off, a Twenty Twenty-Four front page spent 6.6 ms in 24 merges per request; a post with 52 styled blocks spent 12.9 ms in 58 merges. With the resolver cache, total time in get_merged_data() was about 1.9 ms for either page, including the initial merge. These are Gutenberg measurements, not a separate Core benchmark (method and results).

The cache uses the resolver's existing block-registration check and resets on clean_cached_data(). Remove the redundant wp_get_global_settings() cache so it reads the resolver's current data, including after late block registration. Both caches are per-request; the removed cache's theme development mode bypass did not affect data freshness across requests. This also makes the accessor cache proposed in #13214 unnecessary.

Theme supports changed after the first merge require wp_clean_theme_json_cache(). The wp_theme_json_data_* filters already require a reset after their origin has been cached; see Trac #62249. The block-registration check still detects additions only.

Tests cover per-origin caching, independent returned instances, changes to returned data, late block registration, cache clearing, theme switching, and settings accessor invalidation. Reported local validation: themes, blocks, block-supports and global-styles groups passed (2,118 tests, 15 skipped); phpcs and git diff --check passed.

Trac ticket: https://core.trac.wordpress.org/ticket/66280
Related: https://core.trac.wordpress.org/ticket/62249

Closes #13214.

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Claude Code (Claude Fable 5.1) for implementation and tests. Codex (GPT-6) checked the diff and edited the description.

This pull request is for code review only. Keep other discussion in the Trac ticket. Do not merge. See GitHub Pull Requests for Code Review in the Core Handbook.

github-actions · 2026-10-07T14:13:48Z

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WP_Theme_JSON_Resolver::get_merged_data() merged the four origins on every call. Block style variations call it once per block carrying an is-style-* class, and the stylesheet, settings, duotone and REST callers add more merges per request. Cache the merged data per origin for the request, return a clone so callers can modify the result, discard it when new blocks are registered, and clear it in clean_cached_data().

The resolver now caches the merged data, so this cache saved one array read per call. Read through to the resolver on every call and drop the two cache keys from wp_clean_theme_json_cache().

…a(). Merge each origin behind a condition so the method stores the result once and clones once, matching the Gutenberg pull request.

… old cache keys. Match the Gutenberg test from WordPress/gutenberg#81979: the key assertions forbid one past implementation by name and fail only if those exact keys return. Keep the assertion that the accessor reflects resolver data refreshed after a previous call.

tellthemachines · 2026-10-08T04:58:12Z

If we're going with this as alternative to #13214 we should copy the changes from src/wp-includes/block-supports/layout.php from there too.

Match the test name and assertion message from WordPress/gutenberg#81979. The Gutenberg suite defines WP_DEBUG, which bypassed the plugin's removed cache, so the test there cannot show that cache's absence. Core's removed cache was bypassed only in theme development mode, so this test still fails against it.

github-actions · 2026-10-09T12:04:18Z

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props jonsurrell, peterwilsoncc, isabel_brison, ramonopoly, mamaduka.

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tellthemachines

Changes match the respective files in Gutenberg PR. Do we also want to bring the tests from phpunit/wp-theme-json-test.php across?

Also let's copy the changes to src/wp-includes/block-supports/layout.php from #13214.

ramonjd

Ran some tests (local so probably take them with a grain of salt)

Page	Request time, median (trunk → PR)	Peak memory (trunk → PR)	Origins cached	Memory the cache adds
Plain post	49.3 → 44.5 ms (−4.8, −10%)	6,141 → 5,968 KB (−172 KB)	`custom`	10.9 KB
Post with 50 section-styled groups	89.4 → 68.2 ms (−21.2, −24%)	6,477 → 6,389 KB (−88 KB)	`custom`	10.9 KB
Post editor	184.8 → 145.5 ms (−39.4, −21%)	11,295 → 11,561 KB (+265 KB)	`custom`, `theme`	28.3 KB

Mamaduka · 2026-10-14T10:38:00Z

Hey, folks

Just wanted to check if there are any blockers here and if we will commit this enhancement before next week's beta 1.

Tag the tests added for the resolver cache and the settings accessor with Trac ticket 66280.

…tion. Port the styles accessor test from WordPress/gutenberg#81979. The accessor reads the resolver's current data, so a block registered after a previous call appears in the next result.

Remove the static that held the first wp_get_global_styles() result in wp_render_layout_support_flag(). The resolver now caches the merged data, so each read is a cached lookup, and a block registered after the first layout render is reflected in later renders.

sirreal · 2026-10-14T12:26:53Z

Also let's copy the changes to src/wp-includes/block-supports/layout.php from #13214.

Done in 1458bb3.

Add native parameter and return types to the tests, the data provider, the sentinel helper and the filter closures this change adds, and type the provider's rows in its docblock. Make the data provider static, as the other providers in this directory are.

tellthemachines

Thanks for updating, LGTM now!

peterwilsoncc · 2026-10-15T03:31:37Z

I've taken the liberty of merging in trunk and removing some unnecessary tear downs in the tests (filters are reset by the test suite's base tear down).

Otherwise let's ship.

`WP_Theme_JSON_Resolver::get_merged_data()` merged all origins on every call, including once for each rendered block with an `is-style-*` class. Cache the result until a block is registered or `wp_clean_theme_json_cache()` is called, and remove the redundant cache in `wp_get_global_settings()`. Theme support changes made after the first merge require `wp_clean_theme_json_cache()`. Backports WordPress/gutenberg#81979. Developed in: #14071 Props jonsurrell, peterwilsoncc, isabel_brison, ramonopoly. Fixes #66280. See #62249. git-svn-id: https://develop.svn.wordpress.org/trunk@64354 602fd350-edb4-49c9-b593-d223f7449a82

github-actions · 2026-10-15T07:56:17Z

A commit was made that fixes the Trac ticket referenced in the description of this pull request.

SVN changeset: 64354
GitHub commit: 84b4736

This PR will be closed, but please confirm the accuracy of this and reopen if there is more work to be done.

`WP_Theme_JSON_Resolver::get_merged_data()` merged all origins on every call, including once for each rendered block with an `is-style-*` class. Cache the result until a block is registered or `wp_clean_theme_json_cache()` is called, and remove the redundant cache in `wp_get_global_settings()`. Theme support changes made after the first merge require `wp_clean_theme_json_cache()`. Backports WordPress/gutenberg#81979. Developed in: WordPress/wordpress-develop#14071 Props jonsurrell, peterwilsoncc, isabel_brison, ramonopoly. Fixes #66280. See #62249. Built from https://develop.svn.wordpress.org/trunk@64354 git-svn-id: http://core.svn.wordpress.org/trunk@63504 1a063a9b-81f0-0310-95a4-ce76da25c4cd

sirreal mentioned this pull request Oct 7, 2026

Cache the theme.json data merged from all origins WordPress/gutenberg#81979

Merged

sirreal added 3 commits October 7, 2026 18:39

Editor: Remove the object cache from wp_get_global_settings().

b1f3806

The resolver now caches the merged data, so this cache saved one array read per call. Read through to the resolver on every call and drop the two cache keys from wp_clean_theme_json_cache().

Editor: Store and clone the merged data at one exit of get_merged_dat…

75a6e42

…a(). Merge each origin behind a condition so the method stores the result once and clones once, matching the Gutenberg pull request.

sirreal force-pushed the theme-json/cache-merged-data branch from 54fdea9 to 75a6e42 Compare October 7, 2026 14:50

sirreal mentioned this pull request Oct 7, 2026

Try caching wp_get_global_styles #13214

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github-actions Bot mentioned this pull request Oct 9, 2026

PHP backports for WP 7.2 WordPress/gutenberg#83761

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sirreal marked this pull request as ready for review October 9, 2026 12:04

Merge branch 'trunk' into theme-json/cache-merged-data

fef4674

sirreal requested review from ramonjd and tellthemachines October 9, 2026 12:04

tellthemachines reviewed Oct 12, 2026

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ramonjd reviewed Oct 12, 2026

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Comment thread tests/phpunit/tests/theme/wpGetGlobalSettings.php

Comment thread tests/phpunit/tests/theme/wpThemeJsonResolver.php Outdated

sirreal added 4 commits October 14, 2026 16:03

Merge branch 'trunk' into theme-json/cache-merged-data

41d6595

Editor: Add the ticket annotation to the merged data cache tests.

ef87252

Tag the tests added for the resolver cache and the settings accessor with Trac ticket 66280.

Editor: Test that wp_get_global_styles() reflects late block registra…

2df838c

…tion. Port the styles accessor test from WordPress/gutenberg#81979. The accessor reads the resolver's current data, so a block registered after a previous call appears in the next result.

sirreal requested review from ramonjd and tellthemachines October 14, 2026 12:26

tellthemachines approved these changes Oct 14, 2026

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peterwilsoncc added 2 commits October 15, 2026 14:27

Merge branch 'trunk' into theme-json/cache-merged-data

80210a7

Remove unneeded tear downs.

cde8b56

Comment explaining needed tear down.

be84046

peterwilsoncc added the props-bot Adding this label triggers the Props Bot workflow for a PR. label Oct 15, 2026

github-actions Bot removed the props-bot Adding this label triggers the Props Bot workflow for a PR. label Oct 15, 2026

Merge branch 'trunk' into theme-json/cache-merged-data

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github-actions Bot closed this Oct 15, 2026

sirreal deleted the theme-json/cache-merged-data branch October 15, 2026 07:58

sirreal mentioned this pull request Oct 19, 2026

Themes: Record the registered blocks on the first theme.json origin build #14077

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Editor: Cache the theme.json data merged from all origins - #14071

Editor: Cache the theme.json data merged from all origins#14071
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