register_block_style_handle( array $metadata, string $field_name, int $index = 0 ): string|false

Description

Compatibility

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

Parameters

$metadataarray

Block metadata.

$field_namestring

Field name to pick from metadata.

$indexintoptional

Index of the style to register when multiple items passed.
Default 0.Default: 0

Return value

string|false

Style handle provided directly or created through style's registration, or false on failure.

Performance profile

How much work a call to register_block_style_handle() 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

Heavy

Reads or writes the filesystem via filemtime().

Scaling

Constant

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

Instructions

31–129

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 162.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

1

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

What it touches

• filesystemfilesystem accessfilemtime()called directly
• hookthird-party callbacksapply_filters()one call below register_block_style_handle()

Further down the call graph this can also reach option, cache, serialize, transient and query. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 19 distinct outcomes

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

This body has more branch combinations than are worth enumerating, so the table covers the outcomes found first rather than every one that exists.

Uses · 10

• generate_block_asset_handle()Generates the name for an asset based on the name of the block and the field name provided.
• wp_style_is()Checks whether a CSS stylesheet has been added to the queue.
• wp_normalize_path()Normalizes a filesystem path.
• str_starts_with()Polyfill for `str_starts_with()` function added in PHP 8.0.
• wp_should_load_separate_core_block_assets()Checks whether separate styles should be loaded for core blocks.
• remove_block_asset_path_prefix()Removes the block asset's path prefix if provided.
• get_block_asset_url()Gets the URL to a block asset.
• wp_register_style()Registers a CSS stylesheet.
• wp_style_add_data()Adds metadata to a CSS stylesheet.
• is_rtl()Determines whether the current locale is right-to-left (RTL).

Used by · 1

• register_block_type_from_metadata()Registers a block type from the metadata stored in the `block.json` file.

Source code

View on Trac ↗View on GitHub ↗

360function register_block_style_handle( $metadata, $field_name, $index = 0 ) {361	if ( empty( $metadata[ $field_name ] ) ) {362		return false;363	}364 365	$style_handle = $metadata[ $field_name ];366	if ( is_array( $style_handle ) ) {367		if ( empty( $style_handle[ $index ] ) ) {368			return false;369		}370		$style_handle = $style_handle[ $index ];371	}372 373	$style_handle_name = generate_block_asset_handle( $metadata['name'], $field_name, $index );374	// If the style handle is already registered, skip re-registering.375	if ( wp_style_is( $style_handle_name, 'registered' ) ) {376		return $style_handle_name;377	}378 379	static $wpinc_path_norm = '';380	if ( ! $wpinc_path_norm ) {381		$wpinc_path_norm = wp_normalize_path( realpath( ABSPATH . WPINC ) );382	}383 384	$is_core_block = isset( $metadata['file'] ) && str_starts_with( $metadata['file'], $wpinc_path_norm );385	// Skip registering individual styles for each core block when a bundled version provided.386	if ( $is_core_block && ! wp_should_load_separate_core_block_assets() ) {387		return false;388	}389 390	$style_path      = remove_block_asset_path_prefix( $style_handle );391	$is_style_handle = $style_handle === $style_path;392	// Allow only passing style handles for core blocks.393	if ( $is_core_block && ! $is_style_handle ) {394		return false;395	}396	// Return the style handle unless it's the first item for every core block that requires special treatment.397	if ( $is_style_handle && ! ( $is_core_block && 0 === $index ) ) {398		return $style_handle;399	}400 401	// Check whether styles should have a ".min" suffix or not.402	$suffix = SCRIPT_DEBUG ? '' : '.min';403	if ( $is_core_block ) {404		$style_path = ( 'editorStyle' === $field_name ) ? "editor{$suffix}.css" : "style{$suffix}.css";405	}406 407	$style_path_norm = wp_normalize_path( realpath( dirname( $metadata['file'] ) . '/' . $style_path ) );408	$style_uri       = get_block_asset_url( $style_path_norm );409 410	$block_version = ! $is_core_block && isset( $metadata['version'] ) ? $metadata['version'] : false;411	$version       = $style_path_norm && defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ? filemtime( $style_path_norm ) : $block_version;412	$result        = wp_register_style(413		$style_handle_name,414		$style_uri,415		array(),416		$version417	);418	if ( ! $result ) {419		return false;420	}421 422	if ( $style_uri ) {423		wp_style_add_data( $style_handle_name, 'path', $style_path_norm );424 425		if ( $is_core_block ) {426			$rtl_file = str_replace( "{$suffix}.css", "-rtl{$suffix}.css", $style_path_norm );427		} else {428			$rtl_file = str_replace( '.css', '-rtl.css', $style_path_norm );429		}430 431		if ( is_rtl() && file_exists( $rtl_file ) ) {432			wp_style_add_data( $style_handle_name, 'rtl', 'replace' );433			wp_style_add_data( $style_handle_name, 'suffix', $suffix );434			wp_style_add_data( $style_handle_name, 'path', $rtl_file );435		}436	}437 438	return $style_handle_name;439}

Changelog

Introduced in 5.5.0. 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/blocks.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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