WP_Style_Engine_Processor::combine_rules_selectors()

Compatibility

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

Performance profile

How much work a call to WP_Style_Engine_Processor::combine_rules_selectors() 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

Touches nothing outside its own arguments.

Scaling

Scales with input

The body loops, so the work grows with how much data it finds.

Instructions

7–9

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 79.

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 one call costs · 1 distinct outcome

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

Uses · 2

• wp_json_encode()Encodes a variable into JSON, with some confidence checks.
• WP_Style_Engine_CSS_Rule::__construct()Constructor.

Used by · 1

• WP_Style_Engine_Processor::get_css()Gets the CSS rules as a string.

Source code

View on Trac ↗View on GitHub ↗

150	private function combine_rules_selectors() {151		// Build an array of selectors along with the JSON-ified styles to make comparisons easier.152		$selectors_json = array();153		foreach ( $this->css_rules as $rule ) {154			$declarations        = $rule->get_declarations()->get_declarations();155			$declaration_options = $rule->get_declarations()->get_declaration_options();156			ksort( $declarations );157			// Declaration options are keyed by property and are part of the rule identity.158			ksort( $declaration_options );159			foreach ( $declaration_options as $property => $options ) {160				if ( is_array( $options ) ) {161					ksort( $options );162					$declaration_options[ $property ] = $options;163				}164			}165			$selectors_json[ $rule->get_selector() ] = wp_json_encode(166				array(167					'declarations'        => $declarations,168					'declaration_options' => $declaration_options,169				)170			);171		}172 173		// Combine selectors that have the same styles.174		foreach ( $selectors_json as $selector => $json ) {175			// Get selectors that use the same styles.176			$duplicates = array_keys( $selectors_json, $json, true );177			// Skip if there are no duplicates.178			if ( 1 >= count( $duplicates ) ) {179				continue;180			}181 182			$declarations = $this->css_rules[ $selector ]->get_declarations();183 184			foreach ( $duplicates as $key ) {185				// Unset the duplicates from the $selectors_json array to avoid looping through them as well.186				unset( $selectors_json[ $key ] );187				// Remove the rules from the rules collection.188				unset( $this->css_rules[ $key ] );189			}190			// Create a new rule with the combined selectors.191			$duplicate_selectors                     = implode( ',', $duplicates );192			$this->css_rules[ $duplicate_selectors ] = new WP_Style_Engine_CSS_Rule( $duplicate_selectors, $declarations );193		}194	}

Changelog

Introduced in 6.1.0. 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/style-engine/class-wp-style-engine-processor.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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