Tiled Gallery: Fix block validation issues caused by attribute removals

[coder-karen]

Fixes several Tiled Gallery PRs:
#16514
#20756
#42104
#42119

(and others, mentioned in the main Linear issue, to be re-reviewed afterwards).

Related Linear issues: VULCAN-90 (and VULCAN-4, VULCAN-35, VULCAN-27)

Proposed changes:

• Primarily, this PR aims to fix existing Tiled Gallery block validation issue notices in several instances: when copying a post / page on Simple, in the post / page / site editor console generally, when adding the block to a Pattern and viewing that pattern via the site editor, when adding a block as a subsite admin (when part of a multisite), then saving and refreshing the page.
• It also partially addresses an accessibility issue reported recently (ensuring images with alt tags don't also have aria-labels (and that the aria labels are more appropriate) - except when Carousel is enabled.
• It also addresses an issue spotted while working on this - also specific to Simple environments, the custom links were also resulting in a block validation issue. The fix there was to change the attribute they are associated with. This is included in this PR to prevent too many unnecessary deprecation versions.
• The common theme in all environments where validation issues were present, were that the sites were part of a multisite network (for example Simple):
  • Specifically, data-amp-layout and tabindex was being removed from the HTML on Simple sites only (front-end), yet on subsites of multisites, when a Tiled Gallery block was added by a subsite admin, only the tabindex was being removed. The new code includes data-amp-layout (needed if using the AMP plugin and viewing the page in AMP transitional mode), but only if the site is not Simple. It also removes the tabindex (and while at it, the role and aria-label) - only to add them back via PHP on the front-end if Carousel is enabled.
  • As for the causes:
    • The removal of data-amp-layout (as well as data-custom-link in this case) is due to code that strips out data- attributes, unless whitelisted. See this Linear link for related links: VULCAN-90
    • The removal of the tabindex attribute is due to the usage of the unfiltered_html capability on multisites - only superadmins will have that capability. Confirmed in testing by adding the capability back .
• A side effect of removing the data-amp-layout attribute on Simple is that block validation issues in Tiled Galleries added within the Layout block are now not an issue, however layout issues then became visible. These have been fixed with changes in the resize.js file and in the editor scss file (which then required some edits to meet current sass-embedded requirements).
• Deprecations:
  • Two deprecations are needed - one could have worked however that would involve conditionally removing tabindex from the gallery-image/save.js in the v7 deprecation version, if the TG is being added by a non super-admin on a multisite network (or more realistically, anyone who doesn't have unfiltered_html capability on a multisite network - or any user role if DISALLOW_UNFILTERED_HTML is set to true in wp-config.php).
  • Checking for that would mean exposing the user capability information of the person who added the block, which doesn't seem a good idea.
  • To reduce the amount of additional files, where possible deprecation files have imported non-changed non-deprecation files.
• A JS test file has also been introduced, specific to the save.js changes that ultimately had been problematic.
• As an additional note, ideally we'd entirely refactor the Tiled Gallery block to integrate core blocks, depending on priorities. This then should be considered an interim solution - though that said we could also have ended up with similar issues if the same attributes are used (depending on how they would have been added). See https://github.com/Automattic/vulcan/issues/697.

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

Relevant Slack conversation - p1747151379475959-slack-C05PV073SG3

Does this pull request change what data or activity we track or use?

No.

Testing instructions:

On a self-hosted test site, with this PR applied (locally), or on a WoA or Jurassic Ninja test site with the Jetpack Beta tester plugin, and this PR applied. As a note, the reported issues predominantly affect Simple sites and multisites, so prioritize testing those (see further down):

• Create a Tiled Gallery. Set link type to anything, with carousel enabled (/wp-admin/admin.php?page=jetpack#writing).
• There should be no block validation issues. Both in the editor and front-end, behaviour should be as expected.
• On the front-end you should be able to click on the post title then press tab to tab onto the images, and click enter to open them in Carousel - image markup (in the Tiled Gallery, not for Carousel images) should include tabindex of 0, role of button, and an aria-label. In the editor the image markup should not include an aria-label, role or tabindex.
• Disable Carousel, and images on the front-end should have no tabindex, aria-label or role. If link is set to none, you won't be able to click on the images (it won't do anything). For any of the other link options, the link should work. There should still be no aria-label, tabindex or role - as the image is no longer the clickable element but instead is wrapped in an anchor tag.
• Ensure general functionality works as expected, as before.
• You should also be able to observe a 'fix' on the front-end - if you click on the title of the post or page then tab onto an image in the Tiled Gallery, you will be able to tab to the images and hit enter if Carousel is enabled, even if the 'link' for the Tiled Gallery was set to none. On trunk you won't be able to.
• Duplicate a post or page with a Tiled Gallery block (to duplicate, enable the option to copy posts from /wp-admin/admin.php?page=jetpack#writing - this should be enabled by default on Simple). On saving, there should be no block validation errors..
• Make sure custom links work, and adding them (and saving then refreshing the page) does not result in any layout issues, and the links remain (front-end as well).
• To test that updating to this PR doesn't create new block validation issues, add a Tiled Gallery block with the previous stable version of Jetpack, or trunk. Apply this PR, then refresh the editor - there should be no block validation warnings. Open up the post or page preview and notice that there should be no aria-label, tabindex or role applied to images if Carousel is disabled - you may need make a minor change and re-save the post for this to apply though.

Multisites:

• Using Jurassic Ninja specialops (?specialops=true#), create a multisite, and within that multisite network create a subsite.
• On that subsite, create a subsite admin (not a super-admin).
• Log in as that user, and follow the same steps as above.

Simple:

• As above (to enable Carousel visit /wp-admin/options-media.php)
• Open up the site Editor (you'll need a block theme such as Twenty Twenty Five active). Open up 'Patterns', and create a new Pattern with a Tiled Gallery block. Save and return to the patterns page, then search for that Tiled Gallery block (name it Tiled Gallery for example to be able to search for it by name). You should be able to see the block in the pattern preview with no validation errors showing.
• Add a Tiled Gallery within a Layout block, then refresh the page. There should be no block validation issues.

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack), and enable the fix/tiled-gallery-accessibility-related-validation-issues branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack fix/tiled-gallery-accessibility-related-validation-issues

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[github-actions]

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Code Coverage Summary

Coverage changed in 3 files.

File	Coverage	Δ%	Δ Uncovered
projects/plugins/jetpack/extensions/blocks/tiled-gallery/tiled-gallery.php	0/89 (0.00%)	0.00%	4 💔
projects/plugins/jetpack/extensions/blocks/tiled-gallery/layout/mosaic/resize.js	0/40 (0.00%)	0.00%	2 ❤️‍🩹
projects/plugins/jetpack/extensions/blocks/tiled-gallery/gallery-image/save.js	14/14 (100.00%)	100.00%	-13 💚

12 files are newly checked for coverage. Only the first 5 are listed here.

File	Coverage
projects/plugins/jetpack/extensions/blocks/tiled-gallery/deprecated/v7/gallery-image/save.js	0/13 (0.00%) 💔
projects/plugins/jetpack/extensions/blocks/tiled-gallery/deprecated/v7/layout/index.js	0/10 (0.00%) 💔
projects/plugins/jetpack/extensions/blocks/tiled-gallery/deprecated/v7/save.js	0/6 (0.00%) 💔
projects/plugins/jetpack/extensions/blocks/tiled-gallery/deprecated/v8/gallery-image/edit.js	0/39 (0.00%) 💔
projects/plugins/jetpack/extensions/blocks/tiled-gallery/deprecated/v8/gallery-image/save.js	0/13 (0.00%) 💔

Full summary · PHP report · JS report

_{If appropriate, add one of these labels to override the failing coverage check: Covered by non-unit tests Use to ignore the Code coverage requirement check when E2Es or other non-unit tests cover the code Coverage tests to be added later Use to ignore the Code coverage requirement check when tests will be added in a follow-up PR I don't care about code coverage for this PR Use this label to ignore the check for insufficient code coveage.}

[fgiannar]

Many thanks for working on this, Karen 👍

I followed the testing intructions for multisites and everything works as described. I only have a question around using custom links in the Tiled Gallery with Carousel enabled:
Looks like we are never redirected to the specified link. We see the image in the Carousel instead. Just wanted to make sure if this is expected behaviour as I thought that by clicking on the image should redirect me to the corresponding custom link.

[coder-karen]

Thanks for testing @fgiannar !

Looks like we are never redirected to the specified link. We see the image in the Carousel instead.

Yes that's expected. Or rather, that's been the default behaviour as long as I'm aware, as it is also the case if you set the link to the attachment page or media file. In that case it will open up the Carousel if Carousel is enabled. That should be improved though - here is a related issue: #42097
And a related issue for the front-end HTML: VULCAN-153 (which I thought to update in this PR, but in the end wanted to try and keep the scope as small as possible since it is already a big PR).

[fgiannar]

Many thanks for all the additional info, appreciate it!

Tested on a JN multisite and a Simple site and everything works as described 🚢