[Fonts API] Refactor Theme JSON global functions into WP_Fonts_Resolver

lib/class-wp-theme-json-resolver-gutenberg.php

@@ -275,7 +275,7 @@ public static function get_theme_data( $deprecated = array(), $options = array()
 			}
 
 			// BEGIN OF EXPERIMENTAL CODE. Not to backport to core.
-			static::$theme = gutenberg_add_registered_fonts_to_theme_json( static::$theme );
+			static::$theme = WP_Fonts_Resolver::add_missing_fonts_to_theme_json( static::$theme );
 			// END OF EXPERIMENTAL CODE.
 
 		}

lib/experimental/fonts-api/class-wp-fonts-resolver.php

@@ -106,4 +106,293 @@ private static function get_value_from_style( $style, $preset_type = 'font-famil
 		$length = strpos( $style, $ending_pattern ) - $offset;
 		return substr( $style, $offset, $length );
 	}
+
+	/**
+	 * Register fonts defined in theme.json.
+	 *
+	 * @since X.X.X
+	 */
+	public static function register_fonts_from_theme_json() {
+
+		$settings = static::get_settings();
+		// Bail out early if there are no settings for fonts.
+		if ( empty( $settings['typography'] ) || empty( $settings['typography']['fontFamilies'] ) ) {
+			return;
+		}
+
+		list( $fonts, $handles ) = static::parse_font_families( $settings );
+
+		wp_register_fonts( $fonts );
+		wp_enqueue_fonts( $handles );
+	}
+
+	/**
+	 * Add missing fonts to the global styles.
+	 *
+	 * @since X.X.X
+	 *
+	 * @param WP_Theme_JSON_Gutenberg|WP_Theme_JSON $data The global styles.
+	 * @return WP_Theme_JSON_Gutenberg|WP_Theme_JSON The global styles with missing fonts.
+	 */
+	public static function add_missing_fonts_to_theme_json( $data ) {
+		$font_families_registered = wp_fonts()->get_registered_font_families();
+
+		$raw_data = $data->get_raw_data();
+
+		$font_families_from_theme = ! empty( $raw_data['settings']['typography']['fontFamilies']['theme'] )
+			? $raw_data['settings']['typography']['fontFamilies']['theme']
+			: array();
+
+		// Find missing fonts that are not in the theme's theme.json.
+		$to_add = array();
+		if ( ! empty( $font_families_registered ) ) {
+			$to_add = array_diff( $font_families_registered, static::get_font_families( $font_families_from_theme ) );
+		}
+
+		// Bail out early if there are no missing fonts.
+		if ( empty( $to_add ) ) {
+			return $data;
+		}
+
+		/*
+		 * Make sure the path to settings.typography.fontFamilies.theme exists
+		 * before adding missing fonts.
+		 */
+		if ( empty( $raw_data['settings'] ) ) {
+			$raw_data['settings'] = array();
+		}
+		$raw_data['settings'] = static::set_tyopgraphy_settings_array_structure( $raw_data['settings'] );
+
+		foreach ( $to_add as $font_family_handle ) {
+			$raw_data['settings']['typography']['fontFamilies']['theme'][] = wp_fonts()->to_theme_json( $font_family_handle );
+		}
+
+		return new WP_Theme_JSON_Gutenberg( $raw_data );
+	}
+
+	/**
+	 * Returns theme's settings and adds fonts defined in variations.
+	 *
+	 * @since X.X.X
+	 *
+	 * @return array An array containing theme's settings.
+	 */
+	private static function get_settings() {
+		// Get settings.
+		$settings = WP_Theme_JSON_Resolver_Gutenberg::get_merged_data()->get_settings();
+
+		if ( ! is_admin() && ! ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) {
+			return $settings;
+		}
+
+		// If in the editor, add fonts defined in variations.
+		$variations          = WP_Theme_JSON_Resolver_Gutenberg::get_style_variations();
+		$set_theme_structure = true;
+
+		foreach ( $variations as $variation ) {
+
+			// Skip if settings.typography.fontFamilies are not defined in the variation.
+			if ( empty( $variation['settings']['typography']['fontFamilies'] ) ) {
+				continue;
+			}
+
+			// One time, set any missing parts of the array structure.
+			if ( $set_theme_structure ) {
+				$set_theme_structure = false;
+				$settings            = static::set_tyopgraphy_settings_array_structure( $settings );
+			}
+
+			// Merge the variation settings with the global settings.
+			$settings['typography']['fontFamilies']['theme'] = array_merge(
+				$settings['typography']['fontFamilies']['theme'],
+				$variation['settings']['typography']['fontFamilies']['theme']
+			);
+
+			// Make sure there are no duplicates.
+			$settings['typography']['fontFamilies'] = array_unique( $settings['typography']['fontFamilies'] );
+		}
+
+		return $settings;
+	}
+
+	/**
+	 * Converts a list of font families into font handles and returns them as an array.
+	 *
+	 * @since X.X.X
+	 *
+	 * @param array $families_data An array of font families data.
+	 * @return array An array containing font handles.
+	 */
+	private static function get_font_families( $families_data ) {
+		$families = array();
+		foreach ( $families_data as $family ) {
+			$font_family = WP_Fonts_Utils::get_font_family_from_variation( $family );
+			$handle      = WP_Fonts_Utils::convert_font_family_into_handle( $font_family );
+			if ( ! empty( $handle ) ) {
+				$families[ $handle ] = true;
+			}
+		}
+
+		return ! empty( $families ) ? array_keys( $families ) : array();
+	}
+
+	/**
+	 * Parse font families from theme.json.
+	 *
+	 * @since X.X.X
+	 *
+	 * @param array $settings Font settings to parse.
+	 * @return array Returns an array that contains font data and corresponding handles.
+	 */
+	private static function parse_font_families( array $settings ) {
+		$handles = array();
+		$fonts   = array();
+
+		// Look for fontFamilies.
+		foreach ( $settings['typography']['fontFamilies'] as $font_families ) {
+			foreach ( $font_families as $font_family ) {
+
+				// Skip if fontFace is not defined.
+				if ( empty( $font_family['fontFace'] ) ) {
+					continue;
+				}
+
+				$font_family['fontFace'] = (array) $font_family['fontFace'];
+				$font_family_slug        = isset( $font_family['slug'] ) ? $font_family['slug'] : '';
+
+				foreach ( $font_family['fontFace'] as $font_face ) {
+					// Skip if the font was registered through the Fonts API.
+					if ( isset( $font_face['origin'] ) && WP_Fonts::REGISTERED_ORIGIN === $font_face['origin'] ) {
+						continue;
+					}
+
+					// For each font "src", convert the "file:./" placeholder into a theme font file URI.
+					if ( ! empty( $font_face['src'] ) ) {
+						$font_face['src'] = static::to_theme_file_uri( (array) $font_face['src'] );
+					}
+
+					// Convert font-face properties into kebab-case.
+					$font_face = static::to_kebab_case( $font_face );
+
+					// Convert font-face properties into kebab-case.
+					$font_face = static::to_kebab_case( $font_face );
+
+					$font_family_handle = static::get_font_family_handle( $font_family_slug, $font_face );
+
+					// Skip if no font-family handle was found.
+					if ( null === $font_family_handle ) {
+						continue;
+					}
+
+					$handles[] = $font_family_handle;
+					if ( ! array_key_exists( $font_family_handle, $fonts ) ) {
+						$fonts[ $font_family_handle ] = array();
+					}
+
+					$fonts[ $font_family_handle ][] = $font_face;
+				}
+			}
+		}
+
+		return array( $fonts, $handles );
+	}
+
+	/**
+	 * Sets the typography.fontFamilies.theme structure in the given array, if not already set.
+	 * if not already set.
+	 *
+	 * @since X.X.X
+	 *
+	 * @param array $data The target array to process.
+	 * @return array Data array with typography.fontFamilies.theme structure set.
+	 */
+	private static function set_tyopgraphy_settings_array_structure( array $data ) {
+		if ( empty( $data['typography'] ) ) {
+			$data['typography'] = array();
+		}
+		if ( empty( $data['typography']['fontFamilies'] ) ) {
+			$data['typography']['fontFamilies'] = array();
+		}
+		if ( empty( $data['typography']['fontFamilies']['theme'] ) ) {
+			$data['typography']['fontFamilies']['theme'] = array();
+		}
+
+		return $data;
+	}
+
+	/**
+	 * Converts each 'file:./' placeholder into a URI to the font file in the theme.
+	 *
+	 * The 'file:./' is specified in the theme's `theme.json` as a placeholder to be
+	 * replaced with the URI to the font file's location in the theme. When a "src"
+	 * beings with this placeholder, it is replaced, converting the src into a URI.
+	 *
+	 * @since X.X.X
+	 *
+	 * @param array $src An array of font file sources to process.
+	 * @return array An array of font file src URI(s).
+	 */
+	private static function to_theme_file_uri( array $src ) {
+		$placeholder = 'file:./';
+
+		foreach ( $src as $src_key => $src_url ) {
+			// Skip if the src doesn't start with the placeholder, as there's nothing to replace.
+			if ( ! str_starts_with( $src_url, $placeholder ) ) {
+				continue;
+			}
+
+			$src_file        = str_replace( $placeholder, '', $src_url );
+			$src[ $src_key ] = get_theme_file_uri( $src_file );
+		}
+
+		return $src;
+	}
+
+	/**
+	 * Converts all first dimension keys into kebab-case.
+	 *
+	 * @since X.X.X
+	 *
+	 * @param array $data The array to process.
+	 */
+	private static function to_kebab_case( array $data ) {
+		foreach ( $data as $key => $value ) {
+			$kebab_case          = _wp_to_kebab_case( $key );
+			$data[ $kebab_case ] = $value;
+			if ( $kebab_case !== $key ) {
+				unset( $data[ $key ] );
+			}
+		}
+
+		return $data;
+	}
+
+	/**
+	 * Gets the font-family handle if defined in the "slug" or font-face variation.
+	 *
+	 * @since X.X.X
+	 *
+	 * @param string $font_family_slug Font-family "slug".
+	 * @param array  $font_face        Font-face (variation) to search.
+	 * @return string|null Font-family handle on success, else null if not found.
+	 */
+	private static function get_font_family_handle( $font_family_slug, array $font_face ) {
+		$font_family_handle = WP_Fonts_Utils::get_font_family_from_variation( $font_face );
+
+		// Use the defined slug if no handle found.
+		if ( empty( $font_family_handle ) ) {
+			$font_family_handle = $font_family_slug;
+		}
+
+		if ( ! empty( $font_family_handle ) ) {
+			$font_family_handle = WP_Fonts_Utils::convert_font_family_into_handle( $font_family_handle );
+		}
+
+		if ( empty( $font_family_handle ) ) {
+			_doing_it_wrong( __FUNCTION__, __( 'Font family not defined in the variation or "slug".', 'gutenberg' ), '6.1.0' );
+			return null;
+		}
+
+		return $font_family_handle;
+	}
 }

lib/experimental/fonts-api/class-wp-fonts.php

@@ -18,6 +18,15 @@
  */
 class WP_Fonts extends WP_Dependencies {
 
+	/**
+	 * Registered "origin", indicating the font is registered in the API.
+	 *
+	 * @since X.X.X
+	 *
+	 * @var string
+	 */
+	const REGISTERED_ORIGIN = 'gutenberg_wp_fonts_api';
+
 	/**
 	 * An array of registered providers.
 	 *
@@ -731,7 +740,7 @@ public function to_theme_json( $font_family_handle ) {
 			}
 
 			$variation_obj        = $this->registered[ $variation_handle ];
-			$variation_properties = array( 'origin' => 'gutenberg_wp_fonts_api' );
+			$variation_properties = array( 'origin' => static::REGISTERED_ORIGIN );
 			foreach ( $variation_obj->extra['font-properties'] as $property_name => $property_value ) {
 				$property_in_camelcase                          = lcfirst( str_replace( '-', '', ucwords( $property_name, '-' ) ) );
 				$variation_properties[ $property_in_camelcase ] = $property_value;

lib/experimental/fonts-api/fonts-api.php

@@ -241,3 +241,12 @@ function( $mime_types ) {
 		return $mime_types;
 	}
 );
+
+/*
+ * To make sure blocks are registered before any Theme_JSON operations take place, a priority of 21 is used.
+ *
+ * Why 21?
+ * Blocks are registered via the "init" hook with a priority value of `20`, which is dynamically added
+ * during the build. See: tools/webpack/blocks.js.
+ */
+add_action( 'init', 'WP_Fonts_Resolver::register_fonts_from_theme_json', 21 );