wp_get_block_css_selector( WP_Block_Type $block_type, string|array $target = 'root', boolean $fallback = false ): string|null

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$block_typeWP_Block_Type

The block's type.

$targetstring|arrayoptional

The desired selector's target, root or array path.Default: 'root'

$fallbackbooleanoptional

Whether to fall back to broader selector.Default: false

Return value

string|null

CSS selector or null if no selector available.

Performance profile

How much work a call to wp_get_block_css_selector() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Trivial

Touches nothing outside its own arguments.

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

6–67

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 122.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

6

6 places in core call this, so the cost is paid more often than your own code shows.

What one call costs · 14 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_get_block_css_selector() can have, taken from its control-flow graph on PHP 8.5.

Uses · 3

• _wp_array_get()Accesses an array in depth based on a path of keys.
• wp_get_block_css_selector()Determines the CSS selector for the block type and property provided, returning it if available.
• WP_Theme_JSON::scope_selector()Function that scopes a selector with another one. This works a bit like SCSS nesting except the `&` operator isn't supported.

Used by · 6

• WP_Duotone::get_selector()Get the CSS selector for a block type.
• WP_Theme_JSON::get_block_selectors()Returns the selectors metadata for a block.
• WP_Theme_JSON::get_blocks_metadata()Returns the metadata for each block.
• _wp_add_block_level_preset_styles()Render the block level presets stylesheet.
• wp_get_block_css_selector()Determines the CSS selector for the block type and property provided, returning it if available.
• wp_render_block_states_support()Renders per-instance state styles on the frontend.

Source code

View on Trac ↗View on GitHub ↗

504function wp_get_block_css_selector( $block_type, $target = 'root', $fallback = false ) {505	if ( empty( $target ) ) {506		return null;507	}508 509	$has_selectors = ! empty( $block_type->selectors );510 511	// Root Selector.512 513	// Calculated before returning as it can be used as fallback for514	// feature selectors later on.515	$root_selector = null;516 517	if ( $has_selectors && isset( $block_type->selectors['root'] ) ) {518		// Use the selectors API if available.519		$root_selector = $block_type->selectors['root'];520	} elseif ( isset( $block_type->supports['__experimentalSelector'] ) && is_string( $block_type->supports['__experimentalSelector'] ) ) {521		// Use the old experimental selector supports property if set.522		$root_selector = $block_type->supports['__experimentalSelector'];523	} else {524		// If no root selector found, generate default block class selector.525		$block_name    = str_replace( '/', '-', str_replace( 'core/', '', $block_type->name ) );526		$root_selector = ".wp-block-{$block_name}";527	}528 529	// Return selector if it's the root target we are looking for.530	if ( 'root' === $target ) {531		return $root_selector;532	}533 534	// If target is not `root` we have a feature or subfeature as the target.535	// If the target is a string convert to an array.536	if ( is_string( $target ) ) {537		$target = explode( '.', $target );538	}539 540	// Feature Selectors ( May fallback to root selector ).541	if ( 1 === count( $target ) ) {542		$fallback_selector = $fallback ? $root_selector : null;543 544		// Prefer the selectors API if available.545		if ( $has_selectors ) {546			// Look for selector under `feature.root`.547			$path             = array( current( $target ), 'root' );548			$feature_selector = _wp_array_get( $block_type->selectors, $path, null );549 550			if ( $feature_selector ) {551				return $feature_selector;552			}553 554			// Check if feature selector is set via shorthand.555			$feature_selector = _wp_array_get( $block_type->selectors, $target, null );556 557			return is_string( $feature_selector ) ? $feature_selector : $fallback_selector;558		}559 560		// Try getting old experimental supports selector value.561		$path             = array( current( $target ), '__experimentalSelector' );562		$feature_selector = _wp_array_get( $block_type->supports, $path, null );563 564		// Nothing to work with, provide fallback or null.565		if ( null === $feature_selector ) {566			return $fallback_selector;567		}568 569		// Scope the feature selector by the block's root selector.570		return WP_Theme_JSON::scope_selector( $root_selector, $feature_selector );571	}572 573	// Subfeature selector574	// This may fallback either to parent feature or root selector.575	$subfeature_selector = null;576 577	// Use selectors API if available.578	if ( $has_selectors ) {579		$subfeature_selector = _wp_array_get( $block_type->selectors, $target, null );580	}581 582	// Only return if we have a subfeature selector.583	if ( $subfeature_selector ) {

Changelog

Introduced in 6.3.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/global-styles-and-settings.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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