initial commit:

this commit adds a new class to the style engine that manages extensions of the block style definitions
adding tests

lib/load.php

@@ -215,6 +215,9 @@ function gutenberg_is_experiment_enabled( $name ) {
 	require_once __DIR__ . '/../build/style-engine/class-wp-style-engine-css-rules-store-gutenberg.php';
 	require_once __DIR__ . '/../build/style-engine/class-wp-style-engine-processor-gutenberg.php';
 }
+if ( file_exists( __DIR__ . '/../build/style-engine/class-wp-style-engine-block-supports-gutenberg.php' ) ) {
+	require_once __DIR__ . '/../build/style-engine/class-wp-style-engine-block-supports-gutenberg.php';
+}
 
 // Block supports overrides.
 require __DIR__ . '/block-supports/settings.php';

packages/style-engine/class-wp-style-engine-block-supports.php

@@ -0,0 +1,133 @@
+<?php
+/**
+ * WP_Style_Engine_Block_Supports
+ *
+ * Stores block support metadata and associated rules.
+ *
+ * @package Gutenberg
+ */
+
+if ( class_exists( 'WP_Style_Engine_Block_Supports' ) ) {
+	return;
+}
+
+/**
+ * Stores block support metadata and associated rules.
+ *
+ * @access private
+ */
+final class WP_Style_Engine_Block_Supports {
+	/**
+	 * The merged metadata.
+	 *
+	 * @var array
+	 */
+	protected static $merged_block_support_metadata = array();
+
+	/**
+	 * Add block style metadata.
+	 *
+	 * @param array $metadata The $metadata.
+	 *
+	 * @return void
+	 */
+	public static function add_metadata( $metadata = array() ) {
+		// Assigns value to $merged_block_support_metadata if not already set.
+		if ( empty( static::$merged_block_support_metadata ) ) {
+			static::reset_metadata();
+		}
+
+		foreach ( $metadata as $definition_group_key => $definition_group_style ) {
+			if ( ! is_array( $definition_group_style ) || empty( $definition_group_style ) ) {
+				continue;
+			}
+
+			if ( ! array_key_exists( $definition_group_key, static::$merged_block_support_metadata ) ) {
+				static::$merged_block_support_metadata[ $definition_group_key ] = array();
+			}
+
+			foreach ( $definition_group_style as $style_definition_key => $style_definition ) {
+				if ( ! is_array( $style_definition ) || empty( $style_definition ) ) {
+					continue;
+				}
+
+				$array_to_extend         = array_key_exists( $style_definition_key, static::$merged_block_support_metadata[ $definition_group_key ] ) ? static::$merged_block_support_metadata[ $definition_group_key ][ $style_definition_key ] : array();
+				$merged_style_definition = static::merge_custom_style_definitions_metadata( $array_to_extend, $style_definition );
+
+				if ( $merged_style_definition ) {
+					static::$merged_block_support_metadata[ $definition_group_key ][ $style_definition_key ] = $merged_style_definition;
+				}
+			}
+		}
+	}
+
+	/**
+	 * Get the metadata array.
+	 *
+	 * @param array $path A path to an array item in static::$merged_block_support_metadata.
+	 * @return array
+	 */
+	public static function get_metadata( $path = array() ) {
+		// Assigns value to $merged_block_support_metadata if not already set.
+		if ( empty( static::$merged_block_support_metadata ) ) {
+			static::reset_metadata();
+		}
+		if ( ! empty( $path ) ) {
+			return _wp_array_get( static::$merged_block_support_metadata, $path, null );
+		}
+		return static::$merged_block_support_metadata;
+	}
+
+	/**
+	 * Resets the de-referenced metadata array.
+	 *
+	 * @return void
+	 */
+	public static function reset_metadata() {
+		static::$merged_block_support_metadata = wp_json_decode( wp_json_encode( WP_Style_Engine::BLOCK_STYLE_DEFINITIONS_METADATA ), true );
+	}
+
+	/**
+	 * Merges single style definitions with incoming custom style definitions.
+	 *
+	 * @param array $style_definition The internal style definition metadata.
+	 * @param array $custom_definition The custom style definition metadata to be merged.
+	 *
+	 * @return array|void The merged definition metadata.
+	 */
+	protected static function merge_custom_style_definitions_metadata( $style_definition, $custom_definition = array() ) {
+		// Required metadata.
+		if ( ! isset( $style_definition['path'] ) && ! isset( $custom_definition['path'] ) && ! is_array( $custom_definition['path'] ) ) {
+			return;
+		}
+
+		// Only allow strings for valid property keys.
+		if ( ! isset( $custom_definition['property_keys']['default'] ) && ! is_string( $custom_definition['property_keys']['default'] ) ) {
+			return;
+		}
+
+		// Only allow strings for valid property keys.
+		if ( isset( $custom_definition['property_keys']['individual'] ) && ! is_string( $custom_definition['property_keys']['individual'] ) ) {
+			return;
+		}
+
+		// Only allow specific value_func.
+		if ( isset( $custom_definition['value_func'] ) && 'WP_Style_Engine::get_individual_property_css_declarations' !== $custom_definition['value_func'] ) {
+			return;
+		}
+
+		$custom_definition['property_keys']['default'] = sanitize_key( $custom_definition['property_keys']['default'] );
+
+		$valid_keys = array( 'path', 'property_keys', 'css_vars', 'classnames' );
+		foreach ( $valid_keys as $key ) {
+			if ( isset( $custom_definition[ $key ] ) && is_array( $custom_definition[ $key ] ) ) {
+				if ( ! isset( $style_definition[ $key ] ) ) {
+					$style_definition[ $key ] = array();
+				}
+				$style_definition[ $key ] = array_merge( $style_definition[ $key ], $custom_definition[ $key ] );
+			}
+		}
+
+		return $style_definition;
+	}
+}

packages/style-engine/class-wp-style-engine.php

@@ -364,7 +364,7 @@ public static function parse_block_styles( $block_styles, $options ) {
 		}
 
 		// Collect CSS and classnames.
-		foreach ( static::BLOCK_STYLE_DEFINITIONS_METADATA as $definition_group_key => $definition_group_style ) {
+		foreach ( WP_Style_Engine_Block_Supports::get_metadata() as $definition_group_key => $definition_group_style ) {
 			if ( empty( $block_styles[ $definition_group_key ] ) ) {
 				continue;
 			}
@@ -527,7 +527,7 @@ protected static function get_individual_property_css_declarations( $style_value
 
 			// Build a path to the individual rules in definitions.
 			$style_definition_path = array( $definition_group_key, $css_property );
-			$style_definition      = _wp_array_get( static::BLOCK_STYLE_DEFINITIONS_METADATA, $style_definition_path, null );
+			$style_definition      = _wp_array_get( WP_Style_Engine_Block_Supports::get_metadata(), $style_definition_path, null );
 
 			if ( $style_definition && isset( $style_definition['property_keys']['individual'] ) ) {
 				// Set a CSS var if there is a valid preset value.