_data( $args['handle'], 'path', $rtl_file_path );
}
}
}
// Enqueue the stylesheet.
wp_enqueue_style( $args['handle'] );
return $content;
};
$hook = did_action( 'wp_enqueue_scripts' ) ? 'wp_footer' : 'wp_enqueue_scripts';
if ( wp_should_load_block_assets_on_demand() ) {
/**
* Callback function to register and enqueue styles.
*
* @param string $content The block content.
* @param array $block The full block, including name and attributes.
* @return string Block content.
*/
$callback_separate = static function ( $content, $block ) use ( $block_name, $callback ) {
if ( ! empty( $block['blockName'] ) && $block_name === $block['blockName'] ) {
return $callback( $content );
}
return $content;
};
/*
* The filter's callback here is an anonymous function because
* using a named function in this case is not possible.
*
* The function cannot be unhooked, however, users are still able
* to dequeue the stylesheets registered/enqueued by the callback
* which is why in this case, using an anonymous function
* was deemed acceptable.
*/
add_filter( 'render_block', $callback_separate, 10, 2 );
return;
}
/*
* The filter's callback here is an anonymous function because
* using a named function in this case is not possible.
*
* The function cannot be unhooked, however, users are still able
* to dequeue the stylesheets registered/enqueued by the callback
* which is why in this case, using an anonymous function
* was deemed acceptable.
*/
add_filter( $hook, $callback );
// Enqueue assets in the editor.
add_action( 'enqueue_block_assets', $callback );
}
/**
* Loads classic theme styles on classic themes in the frontend.
*
* This is used for backwards compatibility for Button and File blocks specifically.
*
* @since 6.1.0
* @since 6.2.0 Added File block styles.
* @since 6.8.0 Moved stylesheet registration outside of this function.
*/
function wp_enqueue_classic_theme_styles() {
if ( ! wp_theme_has_theme_json() ) {
wp_enqueue_style( 'classic-theme-styles' );
}
}
/**
* Enqueues the assets required for the Command Palette.
*
* @since 6.9.0
*
* @global array $menu
* @global array $submenu
*/
function wp_enqueue_command_palette_assets() {
global $menu, $submenu;
$command_palette_settings = array(
'is_network_admin' => is_network_admin(),
);
if ( $menu ) {
$menu_commands = array();
foreach ( $menu as $menu_item ) {
if ( empty( $menu_item[0] ) || ! empty( $menu_item[1] ) && ! current_user_can( $menu_item[1] ) ) {
continue;
}
// Remove all HTML tags and their contents.
$menu_label = $menu_item[0];
while ( preg_match( '/<[^>]*>/', $menu_label ) ) {
$menu_label = preg_replace( '/<[^>]*>.*?<\/[^>]*>|<[^>]*\/>|<[^>]*>/s', '', $menu_label );
}
$menu_label = trim( $menu_label );
$menu_url = '';
$menu_slug = $menu_item[2];
if ( preg_match( '/\.php($|\?)/', $menu_slug ) || wp_http_validate_url( $menu_slug ) ) {
$menu_url = $menu_slug;
} elseif ( ! empty( menu_page_url( $menu_slug, false ) ) ) {
$menu_url = html_entity_decode( menu_page_url( $menu_slug, false ), ENT_QUOTES, get_bloginfo( 'charset' ) );
}
if ( $menu_url ) {
$menu_commands[] = array(
'label' => $menu_label,
'url' => $menu_url,
'name' => $menu_slug,
);
}
if ( array_key_exists( $menu_slug, $submenu ) ) {
foreach ( $submenu[ $menu_slug ] as $submenu_item ) {
if ( empty( $submenu_item[0] ) || ! empty( $submenu_item[1] ) && ! current_user_can( $submenu_item[1] ) ) {
continue;
}
// Remove all HTML tags and their contents.
$submenu_label = $submenu_item[0];
while ( preg_match( '/<[^>]*>/', $submenu_label ) ) {
$submenu_label = preg_replace( '/<[^>]*>.*?<\/[^>]*>|<[^>]*\/>|<[^>]*>/s', '', $submenu_label );
}
$submenu_label = trim( $submenu_label );
$submenu_url = '';
$submenu_slug = $submenu_item[2];
if ( preg_match( '/\.php($|\?)/', $submenu_slug ) || wp_http_validate_url( $submenu_slug ) ) {
$submenu_url = $submenu_slug;
} elseif ( ! empty( menu_page_url( $submenu_slug, false ) ) ) {
$submenu_url = html_entity_decode( menu_page_url( $submenu_slug, false ), ENT_QUOTES, get_bloginfo( 'charset' ) );
}
if ( $submenu_url ) {
$menu_commands[] = array(
'label' => sprintf(
/* translators: 1: Menu label, 2: Submenu label. */
__( '%1$s > %2$s' ),
$menu_label,
$submenu_label
),
'url' => $submenu_url,
'name' => $menu_slug . '-' . $submenu_item[2],
);
}
}
}
}
$command_palette_settings['menu_commands'] = $menu_commands;
}
wp_enqueue_script( 'wp-commands' );
wp_enqueue_style( 'wp-commands' );
wp_enqueue_script( 'wp-core-commands' );
wp_add_inline_script(
'wp-core-commands',
sprintf(
'wp.coreCommands.initializeCommandPalette( %s );',
wp_json_encode( $command_palette_settings, JSON_HEX_TAG | JSON_UNESCAPED_SLASHES )
)
);
}
/**
* Removes leading and trailing _empty_ script tags.
*
* This is a helper meant to be used for literal script tag construction
* within `wp_get_inline_script_tag()` or `wp_print_inline_script_tag()`.
* It removes the literal values of "" from
* around an inline script after trimming whitespace. Typically this
* is used in conjunction with output buffering, where `ob_get_clean()`
* is passed as the `$contents` argument.
*
* Example:
*
* // Strips exact literal empty SCRIPT tags.
* $js = ';
* 'sayHello();' === wp_remove_surrounding_empty_script_tags( $js );
*
* // Otherwise if anything is different it warns in the JS console.
* $js = '';
* 'console.error( ... )' === wp_remove_surrounding_empty_script_tags( $js );
*
* @since 6.4.0
* @access private
*
* @see wp_print_inline_script_tag()
* @see wp_get_inline_script_tag()
*
* @param string $contents Script body with manually created SCRIPT tag literals.
* @return string Script body without surrounding script tag literals, or
* original contents if both exact literals aren't present.
*/
function wp_remove_surrounding_empty_script_tags( $contents ) {
$contents = trim( $contents );
$opener = '';
if (
strlen( $contents ) > strlen( $opener ) + strlen( $closer ) &&
strtoupper( substr( $contents, 0, strlen( $opener ) ) ) === $opener &&
strtoupper( substr( $contents, -strlen( $closer ) ) ) === $closer
) {
return substr( $contents, strlen( $opener ), -strlen( $closer ) );
} else {
$error_message = __( 'Expected string to start with script tag (without attributes) and end with script tag, with optional whitespace.' );
_doing_it_wrong( __FUNCTION__, $error_message, '6.4' );
return sprintf(
'console.error(%s)',
wp_json_encode(
sprintf(
/* translators: %s: wp_remove_surrounding_empty_script_tags() */
__( 'Function %s used incorrectly in PHP.' ),
'wp_remove_surrounding_empty_script_tags()'
) . ' ' . $error_message
)
);
}
}
/**
* Adds hooks to load block styles on demand in classic themes.
*
* @since 6.9.0
*
* @see _add_default_theme_supports()
*/
function wp_load_classic_theme_block_styles_on_demand() {
// This is not relevant to block themes, as they are opted in to loading separate styles on demand via _add_default_theme_supports().
if ( wp_is_block_theme() ) {
return;
}
/*
* Make sure that wp_should_output_buffer_template_for_enhancement() returns true even if there aren't any
* `wp_template_enhancement_output_buffer` filters added, but do so at priority zero so that applications which
* wish to stream responses can more easily turn this off.
*/
add_filter( 'wp_should_output_buffer_template_for_enhancement', '__return_true', 0 );
// If a site has opted out of the template enhancement output buffer, then bail.
if ( ! wp_should_output_buffer_template_for_enhancement() ) {
return;
}
// The following two filters are added by default for block themes in _add_default_theme_supports().
/*
* Load separate block styles so that the large block-library stylesheet is not enqueued unconditionally, and so
* that block-specific styles will only be enqueued when they are used on the page. A priority of zero allows for
* this to be easily overridden by themes which wish to opt out. If a site has explicitly opted out of loading
* separate block styles, then abort.
*/
add_filter( 'should_load_separate_core_block_assets', '__return_true', 0 );
if ( ! wp_should_load_separate_core_block_assets() ) {
return;
}
/*
* Also ensure that block assets are loaded on demand (although the default value is from should_load_separate_core_block_assets).
* As above, a priority of zero allows for this to be easily overridden by themes which wish to opt out. If a site
* has explicitly opted out of loading block styles on demand, then abort.
*/
add_filter( 'should_load_block_assets_on_demand', '__return_true', 0 );
if ( ! wp_should_load_block_assets_on_demand() ) {
return;
}
// Add hooks which require the presence of the output buffer. Ideally the above two filters could be added here, but they run too early.
add_action( 'wp_template_enhancement_output_buffer_started', 'wp_hoist_late_printed_styles' );
}
/**
* Adds the hooks needed for CSS output to be delayed until after the content of the page has been established.
*
* @since 6.9.0
*
* @see wp_load_classic_theme_block_styles_on_demand()
* @see _wp_footer_scripts()
*/
function wp_hoist_late_printed_styles() {
// Skip the embed template on-demand styles aren't relevant, and there is no wp_head action.
if ( is_embed() ) {
return;
}
// Capture the styles enqueued at the enqueue_block_assets action, so that non-core block styles and global styles can be inserted afterwards during hoisting.
$style_handles_at_enqueue_block_assets = array();
add_action(
'enqueue_block_assets',
static function () use ( &$style_handles_at_enqueue_block_assets ) {
$style_handles_at_enqueue_block_assets = wp_styles()->queue;
},
PHP_INT_MIN
);
add_action(
'enqueue_block_assets',
static function () use ( &$style_handles_at_enqueue_block_assets ) {
$style_handles_at_enqueue_block_assets = array_values( array_diff( wp_styles()->queue, $style_handles_at_enqueue_block_assets ) );
},
PHP_INT_MAX
);
/*
* Add a placeholder comment into the inline styles for wp-block-library, after which the late block styles
* can be hoisted from the footer to be printed in the header by means of a filter below on the template enhancement
* output buffer. The `wp_print_styles` action is used to ensure that if the inline style gets replaced at
* `enqueue_block_assets` or `wp_enqueue_scripts` that the placeholder will be sure to be present.
*/
$placeholder = sprintf( '/*%s*/', uniqid( 'wp_block_styles_on_demand_placeholder:' ) );
add_action(
'wp_print_styles',
static function () use ( $placeholder ) {
wp_add_inline_style( 'wp-block-library', $placeholder );
}
);
/*
* Create a substitute for `print_late_styles()` which is aware of block styles. This substitute does not print
* the styles, but it captures what would be printed for block styles and non-block styles so that they can be
* later hoisted to the HEAD in the template enhancement output buffer. This will run at `wp_print_footer_scripts`
* before `print_footer_scripts()` is called.
*/
$printed_core_block_styles = '';
$printed_other_block_styles = '';
$printed_global_styles = '';
$printed_late_styles = '';
$capture_late_styles = static function () use ( &$printed_core_block_styles, &$printed_other_block_styles, &$printed_global_styles, &$printed_late_styles ) {
// Gather the styles related to on-demand block enqueues.
$all_core_block_style_handles = array();
$all_other_block_style_handles = array();
foreach ( WP_Block_Type_Registry::get_instance()->get_all_registered() as $block_type ) {
if ( str_starts_with( $block_type->name, 'core/' ) ) {
foreach ( $block_type->style_handles as $style_handle ) {
$all_core_block_style_handles[] = $style_handle;
}
} else {
foreach ( $block_type->style_handles as $style_handle ) {
$all_other_block_style_handles[] = $style_handle;
}
}
}
/*
* First print all styles related to blocks which should be inserted right after the wp-block-library stylesheet
* to preserve the CSS cascade. The logic in this `if` statement is derived from `wp_print_styles()`.
*/
$enqueued_core_block_styles = array_values( array_intersect( $all_core_block_style_handles, wp_styles()->queue ) );
if ( count( $enqueued_core_block_styles ) > 0 ) {
ob_start();
wp_styles()->do_items( $enqueued_core_block_styles );
$printed_core_block_styles = ob_get_clean();
}
// Non-core block styles get printed after the classic-theme-styles stylesheet.
$enqueued_other_block_styles = array_values( array_intersect( $all_other_block_style_handles, wp_styles()->queue ) );
if ( count( $enqueued_other_block_styles ) > 0 ) {
ob_start();
wp_styles()->do_items( $enqueued_other_block_styles );
$printed_other_block_styles = ob_get_clean();
}
// Capture the global-styles so that it can be printed separately after classic-theme-styles and other styles enqueued at enqueue_block_assets.
if ( wp_style_is( 'global-styles' ) ) {
ob_start();
wp_styles()->do_items( array( 'global-styles' ) );
$printed_global_styles = ob_get_clean();
}
/*
* Print all remaining styles not related to blocks. This contains a subset of the logic from
* `print_late_styles()`, without admin-specific logic and the `print_late_styles` filter to control whether
* late styles are printed (since they are being hoisted anyway).
*/
ob_start();
wp_styles()->do_footer_items();
$printed_late_styles = ob_get_clean();
};
/*
* If `_wp_footer_scripts()` was unhooked from the `wp_print_footer_scripts` action, or if `wp_print_footer_scripts()`
* was unhooked from running at the `wp_footer` action, then only add a callback to `wp_footer` which will capture the
* late-printed styles.
*
* Otherwise, in the normal case where `_wp_footer_scripts()` will run at the `wp_print_footer_scripts` action, then
* swap out `_wp_footer_scripts()` with an alternative which captures the printed styles (for hoisting to HEAD) before
* proceeding with printing the footer scripts.
*/
$wp_print_footer_scripts_priority = has_action( 'wp_print_footer_scripts', '_wp_footer_scripts' );
if ( false === $wp_print_footer_scripts_priority || false === has_action( 'wp_footer', 'wp_print_footer_scripts' ) ) {
// The normal priority for wp_print_footer_scripts() is to run at 20.
add_action( 'wp_footer', $capture_late_styles, 20 );
} else {
remove_action( 'wp_print_footer_scripts', '_wp_footer_scripts', $wp_print_footer_scripts_priority );
add_action(
'wp_print_footer_scripts',
static function () use ( $capture_late_styles ) {
$capture_late_styles();
print_footer_scripts();
},
$wp_print_footer_scripts_priority
);
}
// Replace placeholder with the captured late styles.
add_filter(
'wp_template_enhancement_output_buffer',
static function ( $buffer ) use ( $placeholder, &$style_handles_at_enqueue_block_assets, &$printed_core_block_styles, &$printed_other_block_styles, &$printed_global_styles, &$printed_late_styles ) {
// Anonymous subclass of WP_HTML_Tag_Processor which exposes underlying bookmark spans.
$processor = new class( $buffer ) extends WP_HTML_Tag_Processor {
/**
* Gets the span for the current token.
*
* @return WP_HTML_Span Current token span.
*/
private function get_span(): WP_HTML_Span {
// Note: This call will never fail according to the usage of this class, given it is always called after ::next_tag() is true.
$this->set_bookmark( 'here' );
return $this->bookmarks['here'];
}
/**
* Inserts text before the current token.
*
* @param string $text Text to insert.
*/
public function insert_before( string $text ) {
$this->lexical_updates[] = new WP_HTML_Text_Replacement( $this->get_span()->start, 0, $text );
}
/**
* Inserts text after the current token.
*
* @param string $text Text to insert.
*/
public function insert_after( string $text ) {
$span = $this->get_span();
$this->lexical_updates[] = new WP_HTML_Text_Replacement( $span->start + $span->length, 0, $text );
}
/**
* Removes the current token.
*/
public function remove() {
$span = $this->get_span();
$this->lexical_updates[] = new WP_HTML_Text_Replacement( $span->start, $span->length, '' );
}
};
// Locate the insertion points in the HEAD.
while ( $processor->next_tag( array( 'tag_closers' => 'visit' ) ) ) {
if (
'STYLE' === $processor->get_tag() &&
'wp-block-library-inline-css' === $processor->get_attribute( 'id' )
) {
$processor->set_bookmark( 'wp_block_library' );
} elseif ( 'HEAD' === $processor->get_tag() && $processor->is_tag_closer() ) {
$processor->set_bookmark( 'head_end' );
break;
} elseif ( ( 'STYLE' === $processor->get_tag() || 'LINK' === $processor->get_tag() ) && $processor->get_attribute( 'id' ) ) {
$id = $processor->get_attribute( 'id' );
$handle = null;
if ( 'STYLE' === $processor->get_tag() ) {
if ( preg_match( '/^(.+)-inline-css$/', $id, $matches ) ) {
$handle = $matches[1];
}
} elseif ( preg_match( '/^(.+)-css$/', $id, $matches ) ) {
$handle = $matches[1];
}
if ( 'classic-theme-styles' === $handle ) {
$processor->set_bookmark( 'classic_theme_styles' );
}
if ( $handle && in_array( $handle, $style_handles_at_enqueue_block_assets, true ) ) {
if ( ! $processor->has_bookmark( 'first_style_at_enqueue_block_assets' ) ) {
$processor->set_bookmark( 'first_style_at_enqueue_block_assets' );
}
$processor->set_bookmark( 'last_style_at_enqueue_block_assets' );
}
}
}
/*
* Insert block styles right after wp-block-library (if it is present). The placeholder CSS comment will
* always be added to the wp-block-library inline style since it gets printed at `wp_head` before the blocks
* are rendered. This means that there may not actually be any block styles to hoist from the footer to
* insert after this inline style. The placeholder CSS comment needs to be added so that the inline style
* gets printed, but if the resulting inline style is empty after the placeholder is removed, then the
* inline style is removed.
*/
if ( $processor->has_bookmark( 'wp_block_library' ) ) {
$processor->seek( 'wp_block_library' );
$css_text = $processor->get_modifiable_text();
/*
* A placeholder CSS comment is added to the inline style in order to force an inline STYLE tag to
* be printed. Now that we've located the inline style, the placeholder comment can be removed. If
* there is no CSS left in the STYLE tag after removing the placeholder (aside from the sourceURL
* comment), then remove the STYLE entirely.
*/
$css_text = str_replace( $placeholder, '', $css_text );
if ( preg_match( ':^/\*# sourceURL=\S+? \*/$:', trim( $css_text ) ) ) {
$processor->remove();
} else {
$processor->set_modifiable_text( $css_text );
}
$inserted_after = $printed_core_block_styles;
$printed_core_block_styles = '';
// If the classic-theme-styles is absent, then the third-party block styles cannot be inserted after it, so they get inserted here.
if ( ! $processor->has_bookmark( 'classic_theme_styles' ) ) {
if ( '' !== $printed_other_block_styles ) {
$inserted_after .= $printed_other_block_styles;
}
$printed_other_block_styles = '';
// If there aren't any other styles printed at enqueue_block_assets either, then the global styles need to also be printed here.
if ( ! $processor->has_bookmark( 'last_style_at_enqueue_block_assets' ) ) {
if ( '' !== $printed_global_styles ) {
$inserted_after .= $printed_global_styles;
}
$printed_global_styles = '';
}
}
if ( '' !== $inserted_after ) {
$processor->insert_after( "\n" . $inserted_after );
}
}
// Insert global-styles after the styles enqueued at enqueue_block_assets.
if ( '' !== $printed_global_styles && $processor->has_bookmark( 'last_style_at_enqueue_block_assets' ) ) {
$processor->seek( 'last_style_at_enqueue_block_assets' );
$processor->insert_after( "\n" . $printed_global_styles );
$printed_global_styles = '';
if ( ! $processor->has_bookmark( 'classic_theme_styles' ) && '' !== $printed_other_block_styles ) {
$processor->insert_after( "\n" . $printed_other_block_styles );
$printed_other_block_styles = '';
}
}
// Insert third-party block styles right after the classic-theme-styles.
if ( '' !== $printed_other_block_styles && $processor->has_bookmark( 'classic_theme_styles' ) ) {
$processor->seek( 'classic_theme_styles' );
$processor->insert_after( "\n" . $printed_other_block_styles );
$printed_other_block_styles = '';
}
// Print all remaining styles.
$remaining_styles = $printed_core_block_styles . $printed_other_block_styles . $printed_global_styles . $printed_late_styles;
if ( $remaining_styles && $processor->has_bookmark( 'head_end' ) ) {
$processor->seek( 'head_end' );
$processor->insert_before( $remaining_styles . "\n" );
}
return $processor->get_updated_html();
}
);
}
/**
* Return the corresponding JavaScript `dataset` name for an attribute
* if it represents a custom data attribute, or `null` if not.
*
* Custom data attributes appear in an element's `dataset` property in a
* browser, but there's a specific way the names are translated from HTML
* into JavaScript. This function indicates how the name would appear in
* JavaScript if a browser would recognize it as a custom data attribute.
*
* Example:
*
* // Dash-letter pairs turn into capital letters.
* 'postId' === wp_js_dataset_name( 'data-post-id' );
* 'Before' === wp_js_dataset_name( 'data--before' );
* '-One--Two---' === wp_js_dataset_name( 'data---one---two---' );
*
* // Not every attribute name will be interpreted as a custom data attribute.
* null === wp_js_dataset_name( 'post-id' );
* null === wp_js_dataset_name( 'data' );
*
* // Some very surprising names will; for example, a property whose name is the empty string.
* '' === wp_js_dataset_name( 'data-' );
* 0 === strlen( wp_js_dataset_name( 'data-' ) );
*
* @since 6.9.0
*
* @see https://html.spec.whatwg.org/#concept-domstringmap-pairs
* @see \wp_html_custom_data_attribute_name()
*
* @param string $html_attribute_name Raw attribute name as found in the source HTML.
* @return string|null Transformed `dataset` name, if interpretable as a custom data attribute, else `null`.
*/
function wp_js_dataset_name( string $html_attribute_name ): ?string {
if ( 0 !== substr_compare( $html_attribute_name, 'data-', 0, 5, true ) ) {
return null;
}
$end = strlen( $html_attribute_name );
/*
* If it contains characters which would end the attribute name parsing then
* something else is wrong and this contains more than just an attribute name.
*/
if ( ( $end - 5 ) !== strcspn( $html_attribute_name, "=/> \t\f\r\n", 5 ) ) {
return null;
}
/**
* > For each name in list, for each U+002D HYPHEN-MINUS character (-)
* > in the name that is followed by an ASCII lower alpha, remove the
* > U+002D HYPHEN-MINUS character (-) and replace the character that
* > followed it by the same character converted to ASCII uppercase.
*
* @see https://html.spec.whatwg.org/#concept-domstringmap-pairs
*/
$custom_name = '';
$at = 5;
$was_at = $at;
while ( $at < $end ) {
$next_dash_at = strpos( $html_attribute_name, '-', $at );
if ( false === $next_dash_at || $next_dash_at === $end - 1 ) {
break;
}
// Transform `-a` to `A`, for example.
$c = $html_attribute_name[ $next_dash_at + 1 ];
if ( ( $c >= 'A' && $c <= 'Z' ) || ( $c >= 'a' && $c <= 'z' ) ) {
$prefix = substr( $html_attribute_name, $was_at, $next_dash_at - $was_at );
$custom_name .= strtolower( $prefix );
$custom_name .= strtoupper( $c );
$at = $next_dash_at + 2;
$was_at = $at;
continue;
}
$at = $next_dash_at + 1;
}
// If nothing has been added it means there are no dash-letter pairs; return the name as-is.
return '' === $custom_name
? strtolower( substr( $html_attribute_name, 5 ) )
: ( $custom_name . strtolower( substr( $html_attribute_name, $was_at ) ) );
}
/**
* Returns a corresponding HTML attribute name for the given name,
* if that name were found in a JS element’s `dataset` property.
*
* Example:
*
* 'data-post-id' === wp_html_custom_data_attribute_name( 'postId' );
* 'data--before' === wp_html_custom_data_attribute_name( 'Before' );
* 'data---one---two---' === wp_html_custom_data_attribute_name( '-One--Two---' );
*
* // Not every attribute name will be interpreted as a custom data attribute.
* null === wp_html_custom_data_attribute_name( '/not-an-attribute/' );
* null === wp_html_custom_data_attribute_name( 'no spaces' );
*
* // Some very surprising names will; for example, a property whose name is the empty string.
* 'data-' === wp_html_custom_data_attribute_name( '' );
*
* @since 6.9.0
*
* @see https://html.spec.whatwg.org/#concept-domstringmap-pairs
* @see \wp_js_dataset_name()
*
* @param string $js_dataset_name Name of JS `dataset` property to transform.
* @return string|null Corresponding name of an HTML custom data attribute for the given dataset name,
* if possible to represent in HTML, otherwise `null`.
*/
function wp_html_custom_data_attribute_name( string $js_dataset_name ): ?string {
$end = strlen( $js_dataset_name );
if ( 0 === $end ) {
return 'data-';
}
/*
* If it contains characters which would end the attribute name parsing then
* something it’s not possible to represent this in HTML.
*/
if ( strcspn( $js_dataset_name, "=/> \t\f\r\n" ) !== $end ) {
return null;
}
$html_name = 'data-';
$at = 0;
$was_at = $at;
while ( $at < $end ) {
$next_upper_after = strcspn( $js_dataset_name, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', $at );
$next_upper_at = $at + $next_upper_after;
if ( $next_upper_at >= $end ) {
break;
}
$prefix = substr( $js_dataset_name, $was_at, $next_upper_at - $was_at );
$html_name .= strtolower( $prefix );
$html_name .= '-' . strtolower( $js_dataset_name[ $next_upper_at ] );
$at = $next_upper_at + 1;
$was_at = $at;
}
if ( $was_at < $end ) {
$html_name .= strtolower( substr( $js_dataset_name, $was_at ) );
}
return $html_name;
}