Add Icon APIs: registry and /wp/v2/icons endpoint

.gitignore

@@ -37,6 +37,7 @@ wp-tests-config.php
 /src/wp-includes/css/*-rtl.css
 /src/wp-includes/blocks/*
 !/src/wp-includes/blocks/index.php
+/src/wp-includes/icons
 /src/wp-includes/build
 /src/wp-includes/theme.json
 /packagehash.txt

src/wp-includes/class-wp-icons-registry.php

@@ -0,0 +1,304 @@
+<?php
+
+/**
+ * Icons API: WP_Icons_Registry class
+ *
+ * @package WordPress
+ * @since 7.0.0
+ */
+
+/**
+ * FIXME
+ *
+ * @since 7.0.0
+ */
+class WP_Icons_Registry {
+	/**
+	 * Registered icons array.
+	 *
+	 * @var array[]
+	 */
+	private $registered_icons = array();
+
+
+	/**
+	 * Container for the main instance of the class.
+	 *
+	 * @var WP_Icons_Registry|null
+	 */
+	private static $instance = null;
+
+	/**
+	 * Constructor.
+	 *
+	 * WP_Icons_Registry is a singleton class, so keep this private.
+	 */
+	private function __construct() {
+		$icons_directory = __DIR__ . '/icons/';
+		$icons_directory = trailingslashit( $icons_directory );
+		$manifest_path   = $icons_directory . 'manifest.php';
+
+		if ( ! is_readable( $manifest_path ) ) {
+			wp_trigger_error(
+				__METHOD__,
+				__( 'Core icon collection manifest is missing or unreadable.', 'gutenberg' )
+			);
+			return;
+		}
+
+		$collection = include $manifest_path;
+
+		if ( empty( $collection ) ) {
+			wp_trigger_error(
+				__METHOD__,
+				__( 'Core icon collection manifest is empty or invalid.', 'gutenberg' )
+			);
+			return;
+		}
+
+		foreach ( $collection as $icon_name => $icon_data ) {
+			if (
+				empty( $icon_data['filePath'] )
+				|| ! is_string( $icon_data['filePath'] )
+			) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Core icon collection manifest must provide valid a "filePath" for each icon.', 'gutenberg' ),
+					'7.0.0'
+				);
+				return;
+			}
+
+			$this->register(
+				'core/' . $icon_name,
+				array(
+					'label'    => $icon_data['label'],
+					'filePath' => $icons_directory . $icon_data['filePath'],
+				)
+			);
+		}
+	}
+
+	/**
+	 * Registers an icon.
+	 *
+	 * @param string $icon_name       Icon name including namespace.
+	 * @param array  $icon_properties {
+	 *     List of properties for the icon.
+	 *
+	 *     @type string $label    Required. A human-readable label for the icon.
+	 *     @type string $content  Optional. SVG markup for the icon.
+	 *                            If not provided, the content will be retrieved from the `filePath` if set.
+	 *                            If both `content` and `filePath` are not set, the icon will not be registered.
+	 *     @type string $filePath Optional. The full path to the file containing the icon content.
+	 * }
+	 * @return bool True if the icon was registered with success and false otherwise.
+	 */
+	private function register( $icon_name, $icon_properties ) {
+		if ( ! isset( $icon_name ) || ! is_string( $icon_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				__( 'Icon name must be a string.', 'gutenberg' ),
+				'7.0.0'
+			);
+			return false;
+		}
+
+		$allowed_keys = array_fill_keys( array( 'label', 'content', 'filePath' ), 1 );
+		foreach ( array_keys( $icon_properties ) as $key ) {
+			if ( ! array_key_exists( $key, $allowed_keys ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					sprintf(
+						// translators: %s is the name of any user-provided key
+						__( 'Invalid icon property: "%s".', 'gutenberg' ),
+						$key
+					),
+					'7.0.0'
+				);
+				return false;
+			}
+		}
+
+		if ( ! isset( $icon_properties['label'] ) || ! is_string( $icon_properties['label'] ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				__( 'Icon label must be a string.', 'gutenberg' ),
+				'7.0.0'
+			);
+			return false;
+		}
+
+		if (
+			( ! isset( $icon_properties['content'] ) && ! isset( $icon_properties['filePath'] ) ) ||
+			( isset( $icon_properties['content'] ) && isset( $icon_properties['filePath'] ) )
+		) {
+			_doing_it_wrong(
+				__METHOD__,
+				__( 'Icons must provide either `content` or `filePath`.', 'gutenberg' ),
+				'7.0.0'
+			);
+			return false;
+		}
+
+		if ( isset( $icon_properties['content'] ) ) {
+			if ( ! is_string( $icon_properties['content'] ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Icon content must be a string.', 'gutenberg' ),
+					'7.0.0'
+				);
+				return false;
+			}
+
+			$sanitized_icon_content = $this->sanitize_icon_content( $icon_properties['content'] );
+			if ( empty( $sanitized_icon_content ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Icon content does not contain valid SVG markup.', 'gutenberg' ),
+					'7.0.0'
+				);
+				return false;
+			}
+		}
+
+		$icon = array_merge(
+			$icon_properties,
+			array( 'name' => $icon_name )
+		);
+
+		$this->registered_icons[ $icon_name ] = $icon;
+
+		return true;
+	}
+
+	/**
+	 * Sanitizes the icon SVG content.
+	 *
+	 * Logic borrowed from twentytwenty.
+	 * @see twentytwenty_get_theme_svg
+	 *
+	 * @param string $icon_content The icon SVG content to sanitize.
+	 * @return string The sanitized icon SVG content.
+	 */
+	private function sanitize_icon_content( $icon_content ) {
+		$allowed_tags = array(
+			'svg'     => array(
+				'class'       => true,
+				'xmlns'       => true,
+				'width'       => true,
+				'height'      => true,
+				'viewbox'     => true,
+				'aria-hidden' => true,
+				'role'        => true,
+				'focusable'   => true,
+			),
+			'path'    => array(
+				'fill'      => true,
+				'fill-rule' => true,
+				'd'         => true,
+				'transform' => true,
+			),
+			'polygon' => array(
+				'fill'      => true,
+				'fill-rule' => true,
+				'points'    => true,
+				'transform' => true,
+				'focusable' => true,
+			),
+		);
+		return wp_kses( $icon_content, $allowed_tags );
+	}
+
+	/**
+	 * Retrieves the content of a registered icon.
+	 *
+	 * @param string $icon_name Icon name including namespace.
+	 * @return string|null The content of the icon, if found.
+	 */
+	private function get_content( $icon_name ) {
+		if ( ! isset( $this->registered_icons[ $icon_name ]['content'] ) ) {
+			$content = file_get_contents(
+				$this->registered_icons[ $icon_name ]['filePath']
+			);
+			$content = $this->sanitize_icon_content( $content );
+
+			if ( empty( $content ) ) {
+				wp_trigger_error(
+					__METHOD__,
+					__( 'Icon content does not contain valid SVG markup.', 'gutenberg' )
+				);
+				return null;
+			}
+
+			$this->registered_icons[ $icon_name ]['content'] = $content;
+		}
+		return $this->registered_icons[ $icon_name ]['content'];
+	}
+
+	/**
+	 * Retrieves an array containing the properties of a registered icon.
+	 *
+	 *
+	 * @param string $icon_name Icon name including namespace.
+	 * @return array|null Registered icon properties or `null` if the icon is not registered.
+	 */
+	public function get_registered_icon( $icon_name ) {
+		if ( ! $this->is_registered( $icon_name ) ) {
+			return null;
+		}
+
+		$icon            = $this->registered_icons[ $icon_name ];
+		$icon['content'] = $icon['content'] ?? $this->get_content( $icon_name );
+
+		return $icon;
+	}
+
+	/**
+	 * Retrieves all registered icons.
+	 *
+	 * @param string $search Optional. Search term by which to filter the icons.
+	 * @return array[] Array of arrays containing the registered icon properties.
+	 */
+	public function get_registered_icons( $search = '' ) {
+		$icons = array();
+
+		foreach ( $this->registered_icons as $icon ) {
+			if ( ! empty( $search ) && false === stripos( $icon['name'], $search ) ) {
+				continue;
+			}
+
+			$icon['content'] = $icon['content'] ?? $this->get_content( $icon['name'] );
+			$icons[]         = $icon;
+		}
+
+		return $icons;
+	}
+
+	/**
+	 * Checks if an icon is registered.
+	 *
+	 *
+	 * @param string $icon_name Icon name including namespace.
+	 * @return bool True if the icon is registered, false otherwise.
+	 */
+	public function is_registered( $icon_name ) {
+		return isset( $this->registered_icons[ $icon_name ] );
+	}
+
+	/**
+	 * Utility method to retrieve the main instance of the class.
+	 *
+	 * The instance will be created if it does not exist yet.
+	 *
+	 *
+	 * @return WP_Icons_Registry The main instance.
+	 */
+	public static function get_instance() {
+		if ( null === self::$instance ) {
+			self::$instance = new self();
+		}
+
+		return self::$instance;
+	}
+}

src/wp-includes/rest-api.php

@@ -424,6 +424,10 @@ function create_initial_rest_routes() {
 	$abilities_run_controller->register_routes();
 	$abilities_list_controller = new WP_REST_Abilities_V1_List_Controller();
 	$abilities_list_controller->register_routes();
+
+	// Icons.
+	$icons_controller = new WP_REST_Icons_Controller();
+	$icons_controller->register_routes();
 }
 
 /**