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   1  <?php
   2  /**
   3   * Style Engine: WP_Style_Engine_Processor class
   4   *
   5   * @package WordPress
   6   * @subpackage StyleEngine
   7   * @since 6.1.0
   8   */
   9  
  10  /**
  11   * Core class used to compile styles from stores or collection of CSS rules.
  12   *
  13   * @since 6.1.0
  14   */
  15  #[AllowDynamicProperties]
  16  class WP_Style_Engine_Processor {
  17  
  18      /**
  19       * A collection of Style Engine Store objects.
  20       *
  21       * @since 6.1.0
  22       * @var WP_Style_Engine_CSS_Rules_Store[]
  23       */
  24      protected $stores = array();
  25  
  26      /**
  27       * The set of CSS rules that this processor will work on.
  28       *
  29       * @since 6.1.0
  30       * @var WP_Style_Engine_CSS_Rule[]
  31       */
  32      protected $css_rules = array();
  33  
  34      /**
  35       * Adds a store to the processor.
  36       *
  37       * @since 6.1.0
  38       *
  39       * @param WP_Style_Engine_CSS_Rules_Store $store The store to add.
  40       * @return WP_Style_Engine_Processor Returns the object to allow chaining methods.
  41       */
  42  	public function add_store( $store ) {
  43          if ( ! $store instanceof WP_Style_Engine_CSS_Rules_Store ) {
  44              _doing_it_wrong(
  45                  __METHOD__,
  46                  __( '$store must be an instance of WP_Style_Engine_CSS_Rules_Store' ),
  47                  '6.1.0'
  48              );
  49              return $this;
  50          }
  51  
  52          $this->stores[ $store->get_name() ] = $store;
  53  
  54          return $this;
  55      }
  56  
  57      /**
  58       * Adds rules to be processed.
  59       *
  60       * @since 6.1.0
  61       * @since 6.6.0 Added support for rules_group.
  62       *
  63       * @param WP_Style_Engine_CSS_Rule|WP_Style_Engine_CSS_Rule[] $css_rules A single, or an array of,
  64       *                                                                       WP_Style_Engine_CSS_Rule objects
  65       *                                                                       from a store or otherwise.
  66       * @return WP_Style_Engine_Processor Returns the object to allow chaining methods.
  67       */
  68  	public function add_rules( $css_rules ) {
  69          if ( ! is_array( $css_rules ) ) {
  70              $css_rules = array( $css_rules );
  71          }
  72  
  73          foreach ( $css_rules as $rule ) {
  74              $selector    = $rule->get_selector();
  75              $rules_group = $rule->get_rules_group();
  76  
  77              /**
  78               * If there is a rules_group and it already exists in the css_rules array,
  79               * add the rule to it.
  80               * Otherwise, create a new entry for the rules_group.
  81               */
  82              if ( ! empty( $rules_group ) ) {
  83                  if ( isset( $this->css_rules[ "$rules_group $selector" ] ) ) {
  84                      $this->css_rules[ "$rules_group $selector" ]->add_declarations( $rule->get_declarations() );
  85                      continue;
  86                  }
  87                  $this->css_rules[ "$rules_group $selector" ] = $rule;
  88                  continue;
  89              }
  90  
  91              // If the selector already exists, add the declarations to it.
  92              if ( isset( $this->css_rules[ $selector ] ) ) {
  93                  $this->css_rules[ $selector ]->add_declarations( $rule->get_declarations() );
  94                  continue;
  95              }
  96              $this->css_rules[ $rule->get_selector() ] = $rule;
  97          }
  98  
  99          return $this;
 100      }
 101  
 102      /**
 103       * Gets the CSS rules as a string.
 104       *
 105       * @since 6.1.0
 106       * @since 6.4.0 The Optimization is no longer the default.
 107       *
 108       * @param array $options   {
 109       *     Optional. An array of options. Default empty array.
 110       *
 111       *     @type bool $optimize Whether to optimize the CSS output, e.g. combine rules.
 112       *                          Default false.
 113       *     @type bool $prettify Whether to add new lines and indents to output.
 114       *                          Defaults to whether the `SCRIPT_DEBUG` constant is defined.
 115       * }
 116       * @return string The computed CSS.
 117       */
 118  	public function get_css( $options = array() ) {
 119          $defaults = array(
 120              'optimize' => false,
 121              'prettify' => defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG,
 122          );
 123          $options  = wp_parse_args( $options, $defaults );
 124  
 125          // If we have stores, get the rules from them.
 126          foreach ( $this->stores as $store ) {
 127              $this->add_rules( $store->get_all_rules() );
 128          }
 129  
 130          // Combine CSS selectors that have identical declarations.
 131          if ( true === $options['optimize'] ) {
 132              $this->combine_rules_selectors();
 133          }
 134  
 135          // Build the CSS.
 136          $css = '';
 137          foreach ( $this->css_rules as $rule ) {
 138              // See class WP_Style_Engine_CSS_Rule for the get_css method.
 139              $css .= $rule->get_css( $options['prettify'] );
 140              $css .= $options['prettify'] ? "\n" : '';
 141          }
 142          return $css;
 143      }
 144  
 145      /**
 146       * Combines selectors from the rules store when they have the same styles.
 147       *
 148       * @since 6.1.0
 149       */
 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              ksort( $declarations );
 156              $selectors_json[ $rule->get_selector() ] = wp_json_encode( $declarations );
 157          }
 158  
 159          // Combine selectors that have the same styles.
 160          foreach ( $selectors_json as $selector => $json ) {
 161              // Get selectors that use the same styles.
 162              $duplicates = array_keys( $selectors_json, $json, true );
 163              // Skip if there are no duplicates.
 164              if ( 1 >= count( $duplicates ) ) {
 165                  continue;
 166              }
 167  
 168              $declarations = $this->css_rules[ $selector ]->get_declarations();
 169  
 170              foreach ( $duplicates as $key ) {
 171                  // Unset the duplicates from the $selectors_json array to avoid looping through them as well.
 172                  unset( $selectors_json[ $key ] );
 173                  // Remove the rules from the rules collection.
 174                  unset( $this->css_rules[ $key ] );
 175              }
 176              // Create a new rule with the combined selectors.
 177              $duplicate_selectors                     = implode( ',', $duplicates );
 178              $this->css_rules[ $duplicate_selectors ] = new WP_Style_Engine_CSS_Rule( $duplicate_selectors, $declarations );
 179          }
 180      }
 181  }