Font Library: Font Collection backend (#54098)

Add extensibility capabilities to the Font Library.
Provides a way to provide collections of typographic fonts by code.

---------

Co-authored-by: Tonya Mork <tonya.mork@automattic.com>

lib/experimental/fonts/font-library/class-wp-font-collection.php

@@ -0,0 +1,95 @@
+<?php
+/**
+ * Font Collection class.
+ *
+ * This file contains the Font Collection class definition.
+ *
+ * @package    WordPress
+ * @subpackage Font Library
+ * @since      6.4.0
+ */
+
+if ( class_exists( 'WP_Font_Collection' ) ) {
+	return;
+}
+
+/**
+ * Font Collection class.
+ *
+ * @since 6.4.0
+ */
+class WP_Font_Collection {
+
+	/**
+	 * Font collection configuration.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @var array
+	 */
+	private $config;
+
+	/**
+	 * WP_Font_Collection constructor.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @param array $config Font collection config options.
+	 *                      See {@see wp_register_font_collection()} for the supported fields.
+	 * @throws Exception If the required parameters are missing.
+	 */
+	public function __construct( $config ) {
+		if ( empty( $config ) || ! is_array( $config ) ) {
+			throw new Exception( 'Font Collection config options is required as a non-empty array.' );
+		}
+
+		if ( empty( $config['id'] ) || ! is_string( $config['id'] ) ) {
+			throw new Exception( 'Font Collection config ID is required as a non-empty string.' );
+		}
+
+		if ( empty( $config['name'] ) || ! is_string( $config['name'] ) ) {
+			throw new Exception( 'Font Collection config name is required as a non-empty string.' );
+		}
+
+		if ( empty( $config['data_json_file'] ) || ! is_string( $config['data_json_file'] ) ) {
+			throw new Exception( 'Font Collection config "data_json_file" option is required as a non-empty string.' );
+		}
+
+		$this->config = $config;
+	}
+
+	/**
+	 * Gets the font collection config.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @return array An array containing the font collection config.
+	 */
+	public function get_config() {
+		return $this->config;
+	}
+
+	/**
+	 * Gets the font collection data.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @return array|WP_Error An array containing the list of font families in theme.json format on success,
+	 *                        else an instance of WP_Error on failure.
+	 */
+	public function get_data() {
+		if ( ! file_exists( $this->config['data_json_file'] ) ) {
+			return new WP_Error( 'font_collection_file_error', __( 'Font Collection data JSON file does not exist.', 'gutenberg' ) );
+		}
+
+		$data = file_get_contents( $this->config['data_json_file'] );
+		if ( empty( $data ) ) {
+			return new WP_Error( 'font_collection_read_error', __( 'Error reading the Font Collection data JSON file contents.', 'gutenberg' ) );
+		}
+
+		$collection_data         = $this->get_config();
+		$collection_data['data'] = $data;
+		unset( $collection_data['data_json_file'] );
+		return $collection_data;
+	}
+}

lib/experimental/fonts/font-library/class-wp-font-library.php

@@ -27,6 +27,61 @@ class WP_Font_Library {
 		'woff2' => 'font/woff2',
 	);
 
+	/**
+	 * Font collections.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @var array
+	 */
+	private static $collections = array();
+
+	/**
+	 * Register a new font collection.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @param array $config Font collection config options.
+	 *                      See {@see wp_register_font_collection()} for the supported fields.
+	 * @return WP_Font_Collection|WP_Error A font collection is it was registered successfully and a WP_Error otherwise.
+	 */
+	public static function register_font_collection( $config ) {
+		$new_collection = new WP_Font_Collection( $config );
+
+		if ( isset( self::$collections[ $config['id'] ] ) ) {
+			return new WP_Error( 'font_collection_registration_error', 'Font collection already registered.' );
+		}
+
+		self::$collections[ $config['id'] ] = $new_collection;
+		return $new_collection;
+	}
+
+	/**
+	 * Gets all the font collections available.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @return array List of font collections.
+	 */
+	public static function get_font_collections() {
+		return self::$collections;
+	}
+
+	/**
+	 * Gets a font collection.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @param string $id Font collection id.
+	 * @return array List of font collections.
+	 */
+	public static function get_font_collection( $id ) {
+		if ( array_key_exists( $id, self::$collections ) ) {
+			return self::$collections[ $id ];
+		}
+		return new WP_Error( 'font_collection_not_found', 'Font collection not found.' );
+	}
+
 	/**
 	 * Gets the upload directory for fonts.
 	 *

lib/experimental/fonts/font-library/class-wp-rest-font-library-controller.php

@@ -67,6 +67,66 @@ public function register_routes() {
 				),
 			)
 		);
+
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base . '/collections',
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_font_collections' ),
+					'permission_callback' => array( $this, 'update_font_library_permissions_check' ),
+				),
+			)
+		);
+
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base . '/collections' . '/(?P<id>[\/\w-]+)',
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_font_collection' ),
+					'permission_callback' => array( $this, 'update_font_library_permissions_check' ),
+				),
+			)
+		);
+	}
+
+	/**
+	 * Gets a font collection.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+	 */
+	public function get_font_collection( $request ) {
+		$id         = $request->get_param( 'id' );
+		$collection = WP_Font_Library::get_font_collection( $id );
+
+		if ( is_wp_error( $collection ) ) {
+			$collection->add_data( array( 'status' => 404 ) );
+			return $collection;
+		}
+
+		return new WP_REST_Response( $collection->get_data() );
+	}
+
+	/**
+	 * Gets the font collections available.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+	 */
+	public function get_font_collections() {
+		$collections = array();
+		foreach ( WP_Font_Library::get_font_collections() as $collection ) {
+			$collections[] = $collection->get_config();
+		}
+
+		return new WP_REST_Response( $collections, 200 );
 	}
 
 	/**

lib/experimental/fonts/font-library/font-library.php

@@ -19,7 +19,7 @@
  *
  * @since 6.4.0
  */
-function gutenberg_init_font_library() {
+function gutenberg_init_font_library_routes() {
 	// @core-merge: This code will go into Core's `create_initial_post_types()`.
 	$args = array(
 		'public'       => true,
@@ -33,5 +33,25 @@ function gutenberg_init_font_library() {
 	$font_library_controller->register_routes();
 }
 
-add_action( 'rest_api_init', 'gutenberg_init_font_library' );
+add_action( 'rest_api_init', 'gutenberg_init_font_library_routes' );
 
+
+if ( ! function_exists( 'wp_register_font_collection' ) ) {
+	/**
+	 * Registers a new Font Collection in the Font Library.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @param string[] $config {
+	 *     Font collection associative array of configuration options.
+	 *
+	 *     @type string $id             The font collection's unique ID.
+	 *     @type string $data_json_file The font collection's data JSON file.
+	 * }
+	 * @return WP_Font_Collection|WP_Error A font collection is it was registered
+	 *                                     successfully, else WP_Error.
+	 */
+	function wp_register_font_collection( $config ) {
+		return WP_Font_Library::register_font_collection( $config );
+	}
+}

lib/load.php

@@ -165,6 +165,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 	( defined( 'FONTS_LIBRARY_ENABLE' ) && FONTS_LIBRARY_ENABLE )
 ) {
 	// Loads the Font Library.
+	require __DIR__ . '/experimental/fonts/font-library/class-wp-font-collection.php';
 	require __DIR__ . '/experimental/fonts/font-library/class-wp-font-library.php';
 	require __DIR__ . '/experimental/fonts/font-library/class-wp-font-family-utils.php';
 	require __DIR__ . '/experimental/fonts/font-library/class-wp-font-family.php';

phpunit/tests/fonts/font-library/wpFontCollection/__construct.php

@@ -0,0 +1,92 @@
+<?php
+/**
+ * Test WP_Font_Collection::__construct().
+ *
+ * @package WordPress
+ * @subpackage Font Library
+ *
+ * @group fonts
+ * @group font-library
+ *
+ * @covers WP_Font_Collection::__construct
+ */
+class Tests_Fonts_WpFontCollection_Construct extends WP_UnitTestCase {
+
+	public function test_should_initialize_data() {
+		$property = new ReflectionProperty( WP_Font_Collection::class, 'config' );
+		$property->setAccessible( true );
+
+		$config          = array(
+			'id'             => 'my-collection',
+			'name'           => 'My Collection',
+			'description'    => 'My collection description',
+			'data_json_file' => 'my-collection-data.json',
+		);
+		$font_collection = new WP_Font_Collection( $config );
+
+		$actual = $property->getValue( $font_collection );
+		$property->setAccessible( false );
+
+		$this->assertSame( $config, $actual );
+	}
+
+	/**
+	 * @dataProvider data_should_throw_exception
+	 *
+	 * @param mixed  $config Config of the font collection.
+	 * @param string $expected_exception_message Expected exception message.
+	 */
+	public function test_should_throw_exception( $config, $expected_exception_message ) {
+		$this->expectException( 'Exception' );
+		$this->expectExceptionMessage( $expected_exception_message );
+		new WP_Font_Collection( $config );
+	}
+
+	/**
+	 * Data provider.
+	 *
+	 * @return array
+	 */
+	public function data_should_throw_exception() {
+		return array(
+			'no id'                           => array(
+				array(
+					'name'           => 'My Collection',
+					'description'    => 'My collection description',
+					'data_json_file' => 'my-collection-data.json',
+				),
+				'Font Collection config ID is required as a non-empty string.',
+			),
+
+			'no config'                       => array(
+				'',
+				'Font Collection config options is required as a non-empty array.',
+			),
+
+			'empty array'                     => array(
+				array(),
+				'Font Collection config options is required as a non-empty array.',
+			),
+
+			'boolean instead of config array' => array(
+				false,
+				'Font Collection config options is required as a non-empty array.',
+			),
+
+			'null instead of config array'    => array(
+				null,
+				'Font Collection config options is required as a non-empty array.',
+			),
+
+			'missing data_json_file'          => array(
+				array(
+					'id'          => 'my-collection',
+					'name'        => 'My Collection',
+					'description' => 'My collection description',
+				),
+				'Font Collection config "data_json_file" option is required as a non-empty string.',
+			),
+
+		);
+	}
+}