Add: WordPress Core get settings ability

src/wp-includes/abilities.php

@@ -9,6 +9,8 @@
 
 declare( strict_types = 1 );
 
+require_once __DIR__ . '/abilities/class-wp-settings-abilities.php';
+
 /**
  * Registers the core ability categories.
  *
@@ -259,4 +261,6 @@ function wp_register_core_abilities(): void {
 			),
 		)
 	);
+
+	WP_Settings_Abilities::register();
 }

src/wp-includes/abilities/class-wp-settings-abilities.php

@@ -0,0 +1,299 @@
+<?php
+/**
+ * Registers core settings abilities.
+ *
+ * This is a utility class to encapsulate the registration of settings-related abilities.
+ * It is not intended to be instantiated or consumed directly by any other code or plugin.
+ *
+ * @package WordPress
+ * @subpackage Abilities_API
+ * @since 6.9.0
+ *
+ * @internal This class is not part of the public API.
+ * @access private
+ */
+
+declare( strict_types=1 );
+
+/**
+ * Registers core settings abilities.
+ *
+ * @since 6.9.0
+ * @access private
+ */
+class WP_Settings_Abilities {
+
+	/**
+	 * Available setting groups with show_in_rest enabled.
+	 *
+	 * @since 6.9.0
+	 * @var array
+	 */
+	private static $available_groups;
+
+	/**
+	 * Dynamic output schema built from registered settings.
+	 *
+	 * @since 6.9.0
+	 * @var array
+	 */
+	private static $output_schema;
+
+	/**
+	 * Registers all settings abilities.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @return void
+	 */
+	public static function register(): void {
+		self::init();
+		self::register_get_settings();
+	}
+
+	/**
+	 * Initializes shared data for settings abilities.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @return void
+	 */
+	private static function init(): void {
+		self::$available_groups = self::get_available_groups();
+		self::$output_schema    = self::build_output_schema();
+	}
+
+	/**
+	 * Gets unique setting groups that have show_in_rest enabled.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @return array List of unique group names.
+	 */
+	private static function get_available_groups(): array {
+		$groups = array();
+
+		foreach ( get_registered_settings() as $args ) {
+			if ( empty( $args['show_in_rest'] ) ) {
+				continue;
+			}
+
+			$group = $args['group'] ?? 'general';
+			if ( ! in_array( $group, $groups, true ) ) {
+				$groups[] = $group;
+			}
+		}
+
+		sort( $groups );
+
+		return $groups;
+	}
+
+	/**
+	 * Builds a rich output schema from registered settings metadata.
+	 *
+	 * Creates a JSON Schema that documents each setting group and its settings
+	 * with their types, titles, descriptions, defaults, and any additional
+	 * schema properties from show_in_rest.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @return array JSON Schema for the output.
+	 */
+	private static function build_output_schema(): array {
+		$group_properties = array();
+
+		foreach ( get_registered_settings() as $option_name => $args ) {
+			if ( empty( $args['show_in_rest'] ) ) {
+				continue;
+			}
+
+			$group = $args['group'] ?? 'general';
+
+			$rest_name = $option_name;
+			if ( is_array( $args['show_in_rest'] ) && ! empty( $args['show_in_rest']['name'] ) ) {
+				$rest_name = $args['show_in_rest']['name'];
+			}
+
+			$setting_schema = array(
+				'type' => $args['type'] ?? 'string',
+			);
+
+			if ( ! empty( $args['label'] ) ) {
+				$setting_schema['title'] = $args['label'];
+			}
+
+			if ( ! empty( $args['description'] ) ) {
+				$setting_schema['description'] = $args['description'];
+			} elseif ( ! empty( $args['label'] ) ) {
+				$setting_schema['description'] = $args['label'];
+			}
+
+			if ( isset( $args['default'] ) ) {
+				$setting_schema['default'] = $args['default'];
+			}
+
+			if ( is_array( $args['show_in_rest'] ) && ! empty( $args['show_in_rest']['schema'] ) ) {
+				$setting_schema = array_merge( $setting_schema, $args['show_in_rest']['schema'] );
+			}
+
+			if ( ! isset( $group_properties[ $group ] ) ) {
+				$group_properties[ $group ] = array(
+					'type'        => 'object',
+					'description' => sprintf(
+						/* translators: %s: Settings group name. */
+						__( '%s settings.' ),
+						ucfirst( $group )
+					),
+					'properties'  => array(),
+				);
+			}
+
+			$group_properties[ $group ]['properties'][ $rest_name ] = $setting_schema;
+		}
+
+		ksort( $group_properties );
+
+		return array(
+			'type'        => 'object',
+			'description' => __( 'Settings grouped by registration group. Each group contains settings with their current values.' ),
+			'properties'  => $group_properties,
+		);
+	}
+
+	/**
+	 * Registers the core/get-settings ability.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @return void
+	 */
+	private static function register_get_settings(): void {
+		wp_register_ability(
+			'core/get-settings',
+			array(
+				'label'               => __( 'Get Settings' ),
+				'description'         => __( 'Returns registered WordPress settings grouped by their registration group. Returns key-value pairs per setting.' ),
+				'category'            => 'site',
+				'input_schema'        => array(
+					'type'                 => 'object',
+					'properties'           => array(
+						'group' => array(
+							'type'        => 'string',
+							'description' => __( 'Filter settings by group name. If omitted, returns all groups.' ),
+							'enum'        => self::$available_groups,
+						),
+					),
+					'additionalProperties' => false,
+					'default'              => array(),
+				),
+				'output_schema'       => self::$output_schema,
+				'execute_callback'    => array( __CLASS__, 'execute_get_settings' ),
+				'permission_callback' => array( __CLASS__, 'check_manage_options' ),
+				'meta'                => array(
+					'annotations'  => array(
+						'readOnlyHint'    => true,
+						'destructiveHint' => false,
+						'idempotentHint'  => true,
+					),
+					'show_in_rest' => true,
+				),
+			)
+		);
+	}
+
+	/**
+	 * Permission callback for settings abilities.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @return bool True if the current user can manage options, false otherwise.
+	 */
+	public static function check_manage_options(): bool {
+		return current_user_can( 'manage_options' );
+	}
+
+	/**
+	 * Execute callback for core/get-settings ability.
+	 *
+	 * Retrieves all registered settings that are exposed to the REST API,
+	 * grouped by their registration group.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @param array $input {
+	 *     Optional. Input parameters.
+	 *
+	 *     @type string $group Optional. Filter settings by group name.
+	 * }
+	 * @return array Settings grouped by registration group.
+	 */
+	public static function execute_get_settings( $input = array() ): array {
+		$input        = is_array( $input ) ? $input : array();
+		$filter_group = ! empty( $input['group'] ) ? $input['group'] : null;
+
+		$registered_settings = get_registered_settings();
+		$settings_by_group   = array();
+
+		foreach ( $registered_settings as $option_name => $args ) {
+			if ( empty( $args['show_in_rest'] ) ) {
+				continue;
+			}
+
+			$group = $args['group'] ?? 'general';
+
+			if ( $filter_group && $group !== $filter_group ) {
+				continue;
+			}
+
+			$rest_name = $option_name;
+			if ( is_array( $args['show_in_rest'] ) && ! empty( $args['show_in_rest']['name'] ) ) {
+				$rest_name = $args['show_in_rest']['name'];
+			}
+
+			$default = $args['default'] ?? null;
+			if ( is_array( $args['show_in_rest'] ) && isset( $args['show_in_rest']['schema']['default'] ) ) {
+				$default = $args['show_in_rest']['schema']['default'];
+			}
+
+			$value = get_option( $option_name, $default );
+			$value = self::cast_value( $value, $args['type'] ?? 'string' );
+
+			if ( ! isset( $settings_by_group[ $group ] ) ) {
+				$settings_by_group[ $group ] = array();
+			}
+
+			$settings_by_group[ $group ][ $rest_name ] = $value;
+		}
+
+		ksort( $settings_by_group );
+
+		return $settings_by_group;
+	}
+
+	/**
+	 * Casts a value to the appropriate type based on the setting's registered type.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @param mixed  $value The value to cast.
+	 * @param string $type  The registered type (string, boolean, integer, number, array, object).
+	 * @return mixed The cast value.
+	 */
+	private static function cast_value( $value, string $type ) {
+		switch ( $type ) {
+			case 'boolean':
+				return (bool) $value;
+			case 'integer':
+				return (int) $value;
+			case 'number':
+				return (float) $value;
+			case 'array':
+			case 'object':
+				return is_array( $value ) ? $value : array();
+			case 'string':
+			default:
+				return (string) $value;
+		}
+	}
+}