Navigation: Use block context to determine whether Page List is nested in Submenu by mcsf · Pull Request #79048 · WordPress/gutenberg

mcsf · 2026-06-09T11:13:50Z

What

Currently, the Page List block has an attribute, isNested, which is automatically set whenever the block renders in the editor, and whose value reflects whether the block has a Navigation Submenu block among its ancestors. The attribute then influences the outcome of the block's server-side render callback.

This is a problematic approach for a few reasons (see original issue and links therein).

This PR inverts the control by:

Letting the Navigation Submenu block provide context to its descendants to signal its presence
Letting the Page List block safely consume that context in its render callback

How

Due to the limited mechanics of block context, Navigation Submenu needs an attribute that we can reliably count on to then provide as context. The block has no such attribute (e.g. id is not required, etc.), so this PR adds a new one — isParentSubmenu — whose value defaults to true. The attribute has no function other than to then provide it as context (core/isInsideSubmenu).

Page List, in turn, can sense that signal by declaring core/isInsideSubmenu among its usesContext data. If the value isn't truthy, it can assume that it is not a descendant of any Submenu.

Finally, Page List can lose the problematic isNested attribute. This PR removes the attribute and adds the respective block deprecation.

Testing

There should be no change in behaviour, except perhaps that it may reduce the occurrence of unwanted editor dirtying (per the original report). Both blocks should work the same, whether they exist independently or whether Page List is found nested within a Navigation Submenu.

github-actions · 2026-06-09T11:13:59Z

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Co-authored-by: mcsf <mcsf@git.wordpress.org>
Co-authored-by: ellatrix <ellatrix@git.wordpress.org>
Co-authored-by: ntsekouras <ntsekouras@git.wordpress.org>
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github-actions · 2026-06-09T11:21:58Z

Size Change: +19 B (0%)

Total Size: 8.46 MB

📦 View Changed

Filename	Size	Change
`build/scripts/block-library/index.min.js`	323 kB	+19 B (+0.01%)

_{compressed-size-action}

github-actions · 2026-06-09T11:48:11Z

Flaky tests detected in de015e5.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/27265276625
📝 Reported issues:

[Flaky Test] should paste block styles using keyboard #78759 in /test/e2e/specs/editor/various/list-view.spec.js

ellatrix · 2026-06-09T13:09:49Z

+		},
+		"isParentSubmenu": {
+			"type": "boolean",
+			"default": true


When would this be false?

Never, but this is us working within the constraints of block-context mechanics. (Is there a better way?)

We need an attribute with some defined default value here, so that it can then propagate as context. Then, Page List will know that a non-empty $block->context['core/isInsideSubmenu'] signals the presence of the ancestor, and convertly that an empty value means that Page List is to be treated as standalone.

Could we use an attribute of the navigation block itself rather than the submenu block?

You're the domain expert, so you tell me. :) I only used Submenu because that was the preexisting logic:

gutenberg/packages/block-library/src/page-list/edit.js

Lines 269 to 273 in 7dd7d62

const blockParents = getBlockParentsByBlockName(

clientId,

'core/navigation-submenu',

true

);

What might we gain or lose by moving it to Navigation? Is there any possible edge case where a Page List would find itself nested somewhere in a Navigation but without a Submenu as an intermediate node? If so, there would now be a change in behaviour in how Page List renders.

I'm going to merge based on Nik's approval, but feel free to open a follow-up if you think it's justified to move the attribute. 🙇

What might we gain or lose by moving it to Navigation? Is there any possible edge case where a Page List would find itself nested somewhere in a Navigation but without a Submenu as an intermediate node? If so, there would now be a change in behaviour in how Page List renders.

I wasn't thinking about moving the attribute, I was wondering if we could use an attribute that already exists in the navigation block, so we don't need to introduce a new one. :)

Ah, well, my question still stands: would it change anything? Any edge cases? To put it differently: why was the original condition for isNested based on Submenu and not Navigation?

Looking at #46414, submenu is the correct place for the context. The page list block gets an extra <ul> wrapper when at the root of a navigation block, and when in a submenu it doesn't.

Looking at #46414, submenu is the correct place for the context. The page list block gets an extra <ul> wrapper when at the root of a navigation block, and when in a submenu it doesn't.

Thanks for the confirmation, that was my intuition. :)

… context

Attribute `isNested` can be safely removed from the schema. Props ntsekouras

ntsekouras

LGTM, thanks!

) ## What this addresses In #78989, opening the post editor with **Show template** enabled can passively render related template parts and referenced Navigation entities. Stale Navigation block attributes are then normalized during render, marking unrelated template parts and navigation menus dirty before the user edits them. Miguel's #79048 removed the Page List `isNested` self-setting path, so this PR now focuses on the remaining `core/navigation` attribute normalization. Without this PR, `core/navigation` converted horizontal `submenuVisibility: "always"` to `"hover"` with `showSubmenuIcon: true`. With this PR, that conversion only runs when the Navigation block, or one of its inner blocks, is actively selected. It doesn't solve the underlying problem of `setAttribute()` calls inside a `useEffect()`, but it softens the impact. A useful follow-up to this PR would reorganize the data model such that we wouldn't need that call at all. ## Testing - Rebased onto current `trunk`, including #79048. - Confirmed in Playground that #79048 removes the Page List `isNested` attribute, but the original #78989 repro still dirties the related Navigation/template-part entities without this PR. - Added an E2E regression test that seeds a template part containing a stale Navigation block referencing a menu, enables Show template in the post editor, and asserts: - passive template rendering leaves dirty entity records empty; - editing the post dirties only the post entity. - Ran `node --check test/e2e/specs/editor/blocks/navigation-passive-rendering.spec.js`. - Ran `git diff --check origin/trunk...HEAD`.

mcsf requested review from ajitbohra, fabiankaegy and juanmaguitar as code owners June 9, 2026 11:13

github-actions Bot added the [Package] Block library /packages/block-library label Jun 9, 2026

mcsf added the [Type] Code Quality Issues or PRs that relate to code quality label Jun 9, 2026

mcsf force-pushed the fix/page-list-isNested branch from 3a52971 to 8ae77ee Compare June 9, 2026 13:08

ellatrix reviewed Jun 9, 2026

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ntsekouras reviewed Jun 9, 2026

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Comment thread packages/block-library/src/page-list/deprecated.js Outdated

mcsf requested a review from scruffian June 9, 2026 16:11

mcsf added 2 commits June 10, 2026 09:59

Navigation: Replace page-list's isNested attr w/ navigation-submenu's…

c813064

… context

Page List: rm block deprecation, keep integration test

de015e5

Attribute `isNested` can be safely removed from the schema. Props ntsekouras

mcsf force-pushed the fix/page-list-isNested branch from f920da8 to de015e5 Compare June 10, 2026 09:00

ntsekouras approved these changes Jun 10, 2026

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mcsf merged commit 6a71326 into trunk Jun 10, 2026
44 of 48 checks passed

mcsf deleted the fix/page-list-isNested branch June 10, 2026 15:17

github-actions Bot added this to the Gutenberg 23.5 milestone Jun 10, 2026

adamziel mentioned this pull request Jun 17, 2026

Avoid dirtying related navigation entities during passive render #79000

Merged

adamziel mentioned this pull request Jun 17, 2026

Multi-entity save flow appearing incorrectly #78989

Closed

mcsf mentioned this pull request Jun 18, 2026

Query: Avoid self-setting attribute antipattern #79328

Closed

cbravobernal assigned mcsf Jun 22, 2026

	const blockParents = getBlockParentsByBlockName(
	clientId,
	'core/navigation-submenu',
	true
	);

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