Allows blocks to override theme preset CSS variables and classes at the block level.

Source: wp-includes/block-supports/settings.php
Since: 6.2.0

Support Key

supports.__experimentalSettings

Block Attributes Read

$block['attrs']['settings'] — A theme.json-compatible settings object applied to this specific block instance.

Functions

_wp_get_presets_class_name()

function _wp_get_presets_class_name( array $block ): string

Since: 6.2.0
Access: private (internal)

Returns wp-settings- followed by an MD5 hash of the serialized block.

_wp_add_block_level_presets_class()

function _wp_add_block_level_presets_class( string $block_content, array $block ): string

Since: 6.2.0
Access: private (internal)

Adds the presets class name to the block’s first HTML tag via WP_HTML_Tag_Processor. Returns early if the block doesn’t support __experimentalSettings or has no settings attribute.

_wp_add_block_level_preset_styles()

function _wp_add_block_level_preset_styles( ?string $pre_render, array $block ): null

Since: 6.2.0
Since: 6.3.0 Updated preset styles to use Selectors API.
Access: private (internal)

Processing:

1. Returns null early if block lacks __experimentalSettings support or has no settings
2. Builds a root selector for preset variables: *,[class*="wp-block"] plus custom selectors from all registered block types that use __experimentalSelector or selectors.root
3. Scopes the root selector under the block’s unique class via WP_Theme_JSON::scope_selector()
4. Sanitizes settings via WP_Theme_JSON::remove_insecure_properties()
5. Creates a WP_Theme_JSON instance and generates two stylesheets:
   • Variables stylesheet: CSS custom properties scoped to the block
   • Presets stylesheet: preset CSS classes scoped to the block and its descendants
6. Enqueues styles via wp_enqueue_block_support_styles()

Always returns null (does not short-circuit block rendering).

Hooks

Notes

• Variables stylesheet: CSS custom properties scoped to the block
• Presets stylesheet: preset CSS classes scoped to the block and its descendants