Tab

Deprecated. This block has been superseded by core/tabs / core/tab-panel. It remains registered for backward compatibility with existing content. Source files live in deprecated/src/tab/.

Note: Gutenberg 23.5 removed the intermediate core/tab button block. See core-tabs.md for the current core/tab-list + tabs attribute model.

Content panel for a single tab within a prc-block/tabs tabbed interface. Each Tab block holds arbitrary inner blocks and exposes its label to the parent Tabs block via context.

Namespace

prc-block/tab

Category

design

Supports

Feature	Detail
Anchor	Yes
HTML	No
Reusable	No
Layout	Switching, vertical alignment, justification, orientation, sizing on children
Spacing	blockGap, padding (no margin)
Typography	fontSize, fontFamily (skip serialization — applied manually in PHP)

Attributes

Attribute	Type	Default	Description
label	string	""	The visible tab label rendered in the tablist by the parent Tabs block.

Available Styles

None. Visual styling is inherited from the parent prc-block/tabs block and its style variants.

Inner Blocks

Accepts any block. Default template inserts a single core/paragraph with placeholder text.

Parent / Ancestor Requirements

Constraint	Value
parent	prc-block/tabs

Context

Direction	Key	Maps to
Provides	tab/label	label attribute

Usage

Tab blocks are inserted exclusively inside a Tabs container. Each tab provides its label via the providesContext mechanism so the parent can render the tablist.

In the editor, the Tab uses a SlotFill pattern (TabFill / TabsListSlot) to render its label button into the parent's tab bar. Only the currently selected tab's inner content is visible.

Inspector controls:

• Tab Label — text control mirroring the inline RichText label.
• Is Default Tab — toggle that sets the parent Tabs block's activeTabIndex to this tab's index so it displays on page load.

Block Markup (save)

<section class="wp-block-prc-block-tab" id="{tabPanelId}">
	<!-- inner blocks -->
</section>

The id is derived from either a user-set anchor or an auto-generated slug from the label.

PHP Rendering

class-tab.php (PRC\Platform\Blocks\Tab)

The render callback uses WP_HTML_Tag_Processor to augment the saved <section>:

1. Sets data-wp-interactive="prc-block/tabs" to join the parent's Interactivity API store.
2. Injects data-wp-context with { tab: { id } }.
3. Adds role="tabpanel" and aria-labelledby="tab__{id}".
4. Binds visibility: data-wp-bind--hidden="!state.isActiveTab".
5. Binds tabindex: data-wp-bind--tabindex="state.tabIndexAttribute".
6. Manually serializes typography classes (has-{size}-font-size, has-{family}-font-family) and inline styles since __experimentalSkipSerialization is enabled.

Frontend Interactivity

The Tab block does not register its own Interactivity API store. It participates in the prc-block/tabs store defined by the parent Tabs block. The store's state.isActiveTab computed property compares the tab's context-provided index against context.activeTabIndex to toggle visibility.

Related Blocks

Block	Relationship
prc-block/tabs	Required parent container
core/tabs	Core replacement (the PRC tabs block is deprecated in the editor inserter)