Forms: disable device visibility on fields/inputs, honor per-viewport hiding on labels

[CGastrell]

Proposed changes

Interim measure for FORMS-694 while we decide whether to fully support per-field device visibility.

What the GB control actually does. The block "visibility" support exposes two modes behind a single supports.visibility boolean: Hide everywhere (writes blockVisibility = false) and per-viewport "Hide on mobile/tablet/desktop" (writes { viewport: … }).

How they behave on our (dynamic) form blocks:

• Per-viewport "Hide on…" is not honored — fields flatten into a shortcode-style array and bypass core's render_block class injection, so wp-block-hidden-* + the media-query CSS never reach the field. Worse, it can't be made safe on a required field: both server (validate()) and client (isFormValid) validation are viewport-blind, so a required field hidden on mobile stays required but unfillable → dead form.
• "Hide everywhere" does work on fields (the field's shortcode is dropped before parse, so it's never validated/submitted — required-safe), but the single boolean bundles it with the broken per-viewport mode and we can't split them.
• Inputs and choice/option blocks are inert in every mode (the field renderer reads their attrs directly and discards their rendered output).

So this disables visibility on every field, input, and choice/option block (the only one that keeps it is the label — see below).

Labels keep their support — and now honor per-viewport hiding too. Label hiding never touches input/validation/submission (it's pure presentation), so the viewport pitfall doesn't apply. Full-hide was already wired via labelhiddenbyblockvisibility; this adds the per-viewport case: the block→shortcode bridge reads blockVisibility.viewport and adds the same wp-block-hidden-{mobile,tablet,desktop} classes Gutenberg would to the label the field renderer emits. The matching media-query CSS is already registered by core's render_block visibility filter (the label keeps visibility support, so the filter runs on it — it just couldn't attach the class because that output is discarded). Applied across the default, outlined, animated, and below label styles.

Applied consistently on both registrations:

• JS — shared/settings/index.js (all field blocks), plus per-block visibility: false on the input variants (input, input-range, input-rating, input-image-option, phone-input, dropzone) and choice/option blocks (option, options, fieldset-image-options, deprecated field-option-*).
• PHP — a register_block_type_args filter matching all jetpack/field-*, jetpack/input*, phone-input, dropzone, and the option containers, mirroring the JS.

Note: this currently means a per-block opt-out duplicated across ~15 blocks. The cleaner end state — a shared supports array array_merge'd into each declaration, mirroring the JS defaultSettings — is tracked as a follow-up (TODO in the PHP filter).

Related

• FORMS-694

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

No.

Testing instructions

• In the block editor, add a Form block and select any field, its input, or a choice/option — the visibility control is gone. Select a field's label — it's still there (the only forms block that keeps it). Select a non-form block (e.g. a paragraph) — unaffected.
• Set a field's label to "Hide on mobile" and view the form on the frontend: the <label> gets wp-block-hidden-mobile and the @media (width <= 480px){…display:none} rule is emitted, so it hides on mobile. Full-hide on a label still removes it entirely.
• Verified registration parity both sides: editor wp.blocks.hasBlockSupport('jetpack/field-name','visibility',true) === false for fields/input and true for labels/options; server WP_Block_Type_Registry reports the same. PHP Contact_Form_Block_Test passes.

Deferred (separate decision, FORMS-694)

Fully supporting per-field device visibility would require honoring viewport hiding inside the forms render pipeline and a viewport flag on the submission so required/validation can be skipped for the hidden viewport on both client and server — plus token handling. Likely not worth it; tracked in FORMS-694.

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Code Coverage Summary

Coverage changed in 3 files.

File	Coverage	Δ%	Δ Uncovered
projects/packages/forms/src/contact-form/class-contact-form-field.php	1112/1796 (61.92%)	-0.01%	1 ❤️‍🩹
projects/packages/forms/src/blocks/contact-form/class-contact-form-block.php	612/676 (90.53%)	0.13%	0 💚
projects/packages/forms/src/contact-form/class-contact-form-plugin.php	700/1562 (44.81%)	0.18%	0 💚

Full summary · PHP report · JS report

[LiamSarsfield]

Nice work on this, the interim approach makes sense. I double-checked the part everyone was unsure about: supports.visibility = false is the correct WP 7.0 opt-out key, and the label mapping reads the right metadata.blockVisibility.viewport.* shape, so the core of this is solid. A couple of things Claude/Codex spotted that may be worth addressing but will defer to you:

• The control still shows on the other input blocks. The disable covers jetpack/input and jetpack/field-*, but a few siblings slip through: jetpack/phone-input, jetpack/input-rating, jetpack/input-range, and jetpack/input-image-option have no visibility: false in their JS and don't match the PHP filter. They flatten through the same shortcode path, so the dead "Hide on…" control is still reachable on the telephone/rating/slider/image-select inner inputs. Might be the perfect excuse to do the shared supports list your TODO already calls out?

• Per-viewport label hide drops the input's accessible name. Hiding a label on a viewport adds wp-block-hidden-{viewport} (display:none), but the aria-label fallback only fires on full-hide, so the input ends up with no accessible name on that viewport. Happy either way: wire the fallback into the per-viewport path, or just note it's visual-only for now.

[LiamSarsfield]

The input-block gap from last round. phone-input, range/rating/image, and dropzone are covered now in both JS and PHP, and the visibility key checks out against WP 7.0 core. 🚀

Some nice to haves that may be worth addressing:

Tests. Only the jetpack/input supports line is locked down today, so reverting the per-viewport label mapping, the full-hide case, or any widened input would stay green. That's the gap that needed a follow-up commit this round. A @dataProvider test on disable_field_visibility_support() across the name matrix (a field, a field-option-*, the prefix inputs, phone-input/dropzone, a non-forms block), plus a couple of Contact_Form_Plugin_Test cases for blockVisibility = false and viewport.mobile = false, covers it.

Grouped fields skip full-hide on their label. render_legend_as_label() never checks labelhiddenbyblockvisibility, so a fully-hidden label still renders on radio, checkbox-multiple, image-select, and rating, while render_label() honors it. It predates this PR, but since this is the change that makes labels honor visibility, finishing it here (or a fast-follow) would round it out. The per-viewport classes already reach the legend, so only the full-hide branch is missing.