WP_Theme_JSON::process_blocks_custom_css( string $css, string $selector ): string
- Since
- 6.2.0, 6.6.0, 7.0.0
- Source
wp-includes/class-wp-theme-json.php:2048
Compatibility
- WordPress
- since 7.0.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$cssstring- The CSS to process.
$selectorstring- The selector to nest.
Return value
string- The processed CSS.
Performance profile
How much work a call to WP_Theme_JSON::process_blocks_custom_css() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Light
- Scaling
- Scales with input
- Instructions
- 6–14
- Plugin surface
- None
- Called by
- 3
Touches nothing outside its own arguments.
The body loops, so the work grows with what you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 84.
Nothing here hands control to plugin code.
3 places in core call this, so the cost is paid more often than your own code shows.
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost WP_Theme_JSON::process_blocks_custom_css() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
empty($css) | 6 | none |
!empty($css) | 13–14 | explode() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 82 | 6–14 | 9 | 2 fewer instructions than PHP 8.5 |
| 8.5 | 84 | 6–14 | 9 | |
| 8.4 | 84 | 6–14 | 9 | 19 fewer instructions than PHP 8.3 |
| 8.3 | 103 | 6–14 | 9 | |
| 8.2 | 103 | 6–14 | 9 | |
| 8.1 | 103 | 6–14 | 9 | 1 fewer instruction than PHP 7.4 |
| 7.4 | 104 | 6–14 | 9 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 4
- str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
- str_starts_with()Polyfill for `str_starts_with()` function added in PHP 8.0.
- static::scope_selector()
- static::append_to_selector()
Used by · 3
- WP_Theme_JSON::get_custom_css()Returns the global styles custom CSS.
- WP_Theme_JSON::get_styles_for_block()Gets the CSS rules for a particular block from theme.json.
- wp_render_custom_css_support_styles()Render the custom CSS stylesheet and add class name to block as required.
Source code
public static function process_blocks_custom_css( $css, $selector ) { $processed_css = ''; if ( empty( $css ) ) { return $processed_css; } // Split CSS nested rules. $parts = explode( '&', $css ); foreach ( $parts as $part ) { if ( empty( $part ) ) { continue; } $is_root_css = ( ! str_contains( $part, '{' ) ); if ( $is_root_css ) { // If the part doesn't contain braces, it applies to the root level. $processed_css .= ':root :where(' . trim( $selector ) . '){' . trim( $part ) . '}'; } else { // If the part contains braces, it's a nested CSS rule. $part = explode( '{', str_replace( '}', '', $part ) ); if ( count( $part ) !== 2 ) { continue; } $nested_selector = $part[0]; $css_value = $part[1]; /* * Handle pseudo elements such as ::before, ::after etc. Regex will also * capture any leading combinator such as >, +, or ~, as well as spaces. * This allows pseudo elements as descendants e.g. `.parent ::before`. */ $matches = array(); $has_pseudo_element = preg_match( '/([>+~\s]*::[a-zA-Z-]+)/', $nested_selector, $matches ); $pseudo_part = $has_pseudo_element ? $matches[1] : ''; $nested_selector = $has_pseudo_element ? str_replace( $pseudo_part, '', $nested_selector ) : $nested_selector; // Finalize selector and re-append pseudo element if required. $part_selector = str_starts_with( $nested_selector, ' ' ) ? static::scope_selector( $selector, $nested_selector ) : static::append_to_selector( $selector, $nested_selector ); $final_selector = ":root :where($part_selector)$pseudo_part"; $processed_css .= $final_selector . '{' . trim( $css_value ) . '}'; } } return $processed_css; }Changelog
Introduced in 6.2.0. Unchanged from 6.7.7 through 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/class-wp-theme-json.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.