diff options
Diffstat (limited to 'wp-includes/fonts/class-wp-font-face.php')
| -rw-r--r-- | wp-includes/fonts/class-wp-font-face.php | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/wp-includes/fonts/class-wp-font-face.php b/wp-includes/fonts/class-wp-font-face.php new file mode 100644 index 0000000..974e13e --- /dev/null +++ b/wp-includes/fonts/class-wp-font-face.php @@ -0,0 +1,430 @@ +<?php +/** + * WP_Font_Face class. + * + * @package WordPress + * @subpackage Fonts + * @since 6.4.0 + */ + +/** + * Font Face generates and prints `@font-face` styles for given fonts. + * + * @since 6.4.0 + */ +class WP_Font_Face { + + /** + * The font-face property defaults. + * + * @since 6.4.0 + * + * @var string[] + */ + private $font_face_property_defaults = array( + 'font-family' => '', + 'font-style' => 'normal', + 'font-weight' => '400', + 'font-display' => 'fallback', + ); + + /** + * Valid font-face property names. + * + * @since 6.4.0 + * + * @var string[] + */ + private $valid_font_face_properties = array( + 'ascent-override', + 'descent-override', + 'font-display', + 'font-family', + 'font-stretch', + 'font-style', + 'font-weight', + 'font-variant', + 'font-feature-settings', + 'font-variation-settings', + 'line-gap-override', + 'size-adjust', + 'src', + 'unicode-range', + ); + + /** + * Valid font-display values. + * + * @since 6.4.0 + * + * @var string[] + */ + private $valid_font_display = array( 'auto', 'block', 'fallback', 'swap', 'optional' ); + + /** + * Array of font-face style tag's attribute(s) + * where the key is the attribute name and the + * value is its value. + * + * @since 6.4.0 + * + * @var string[] + */ + private $style_tag_attrs = array(); + + /** + * Creates and initializes an instance of WP_Font_Face. + * + * @since 6.4.0 + */ + public function __construct() { + if ( + function_exists( 'is_admin' ) && ! is_admin() + && + function_exists( 'current_theme_supports' ) && ! current_theme_supports( 'html5', 'style' ) + ) { + $this->style_tag_attrs = array( 'type' => 'text/css' ); + } + } + + /** + * Generates and prints the `@font-face` styles for the given fonts. + * + * @since 6.4.0 + * + * @param array[][] $fonts Optional. The font-families and their font variations. + * See {@see wp_print_font_faces()} for the supported fields. + * Default empty array. + */ + public function generate_and_print( array $fonts ) { + $fonts = $this->validate_fonts( $fonts ); + + // Bail out if there are no fonts are given to process. + if ( empty( $fonts ) ) { + return; + } + + $css = $this->get_css( $fonts ); + + /* + * The font-face CSS is contained within <style> tags and can only be interpreted + * as CSS in the browser. Using wp_strip_all_tags() is sufficient escaping + * to avoid malicious attempts to close </style> and open a <script>. + */ + $css = wp_strip_all_tags( $css ); + + // Bail out if there is no CSS to print. + if ( empty( $css ) ) { + return; + } + + printf( $this->get_style_element(), $css ); + } + + /** + * Validates each of the font-face properties. + * + * @since 6.4.0 + * + * @param array $fonts The fonts to valid. + * @return array Prepared font-faces organized by provider and font-family. + */ + private function validate_fonts( array $fonts ) { + $validated_fonts = array(); + + foreach ( $fonts as $font_faces ) { + foreach ( $font_faces as $font_face ) { + $font_face = $this->validate_font_face_declarations( $font_face ); + // Skip if failed validation. + if ( false === $font_face ) { + continue; + } + + $validated_fonts[] = $font_face; + } + } + + return $validated_fonts; + } + + /** + * Validates each font-face declaration (property and value pairing). + * + * @since 6.4.0 + * + * @param array $font_face Font face property and value pairings to validate. + * @return array|false Validated font-face on success, or false on failure. + */ + private function validate_font_face_declarations( array $font_face ) { + $font_face = wp_parse_args( $font_face, $this->font_face_property_defaults ); + + // Check the font-family. + if ( empty( $font_face['font-family'] ) || ! is_string( $font_face['font-family'] ) ) { + // @todo replace with `wp_trigger_error()`. + _doing_it_wrong( + __METHOD__, + __( 'Font font-family must be a non-empty string.' ), + '6.4.0' + ); + return false; + } + + // Make sure that local fonts have 'src' defined. + if ( empty( $font_face['src'] ) || ( ! is_string( $font_face['src'] ) && ! is_array( $font_face['src'] ) ) ) { + // @todo replace with `wp_trigger_error()`. + _doing_it_wrong( + __METHOD__, + __( 'Font src must be a non-empty string or an array of strings.' ), + '6.4.0' + ); + return false; + } + + // Validate the 'src' property. + foreach ( (array) $font_face['src'] as $src ) { + if ( empty( $src ) || ! is_string( $src ) ) { + // @todo replace with `wp_trigger_error()`. + _doing_it_wrong( + __METHOD__, + __( 'Each font src must be a non-empty string.' ), + '6.4.0' + ); + return false; + } + } + + // Check the font-weight. + if ( ! is_string( $font_face['font-weight'] ) && ! is_int( $font_face['font-weight'] ) ) { + // @todo replace with `wp_trigger_error()`. + _doing_it_wrong( + __METHOD__, + __( 'Font font-weight must be a properly formatted string or integer.' ), + '6.4.0' + ); + return false; + } + + // Check the font-display. + if ( ! in_array( $font_face['font-display'], $this->valid_font_display, true ) ) { + $font_face['font-display'] = $this->font_face_property_defaults['font-display']; + } + + // Remove invalid properties. + foreach ( $font_face as $property => $value ) { + if ( ! in_array( $property, $this->valid_font_face_properties, true ) ) { + unset( $font_face[ $property ] ); + } + } + + return $font_face; + } + + /** + * Gets the style element for wrapping the `@font-face` CSS. + * + * @since 6.4.0 + * + * @return string The style element. + */ + private function get_style_element() { + $attributes = $this->generate_style_element_attributes(); + + return "<style id='wp-fonts-local'{$attributes}>\n%s\n</style>\n"; + } + + /** + * Gets the defined <style> element's attributes. + * + * @since 6.4.0 + * + * @return string A string of attribute=value when defined, else, empty string. + */ + private function generate_style_element_attributes() { + $attributes = ''; + foreach ( $this->style_tag_attrs as $name => $value ) { + $attributes .= " {$name}='{$value}'"; + } + return $attributes; + } + + /** + * Gets the `@font-face` CSS styles for locally-hosted font files. + * + * This method does the following processing tasks: + * 1. Orchestrates an optimized `src` (with format) for browser support. + * 2. Generates the `@font-face` for all its fonts. + * + * @since 6.4.0 + * + * @param array $font_faces The font-faces to generate @font-face CSS styles. + * @return string The `@font-face` CSS styles. + */ + private function get_css( $font_faces ) { + $css = ''; + + foreach ( $font_faces as $font_face ) { + // Order the font's `src` items to optimize for browser support. + $font_face = $this->order_src( $font_face ); + + // Build the @font-face CSS for this font. + $css .= '@font-face{' . $this->build_font_face_css( $font_face ) . '}' . "\n"; + } + + // Don't print the last newline character. + return rtrim( $css, "\n" ); + } + + /** + * Orders `src` items to optimize for browser support. + * + * @since 6.4.0 + * + * @param array $font_face Font face to process. + * @return array Font-face with ordered src items. + */ + private function order_src( array $font_face ) { + if ( ! is_array( $font_face['src'] ) ) { + $font_face['src'] = (array) $font_face['src']; + } + + $src = array(); + $src_ordered = array(); + + foreach ( $font_face['src'] as $url ) { + // Add data URIs first. + if ( str_starts_with( trim( $url ), 'data:' ) ) { + $src_ordered[] = array( + 'url' => $url, + 'format' => 'data', + ); + continue; + } + $format = pathinfo( $url, PATHINFO_EXTENSION ); + $src[ $format ] = $url; + } + + // Add woff2. + if ( ! empty( $src['woff2'] ) ) { + $src_ordered[] = array( + 'url' => $src['woff2'], + 'format' => 'woff2', + ); + } + + // Add woff. + if ( ! empty( $src['woff'] ) ) { + $src_ordered[] = array( + 'url' => $src['woff'], + 'format' => 'woff', + ); + } + + // Add ttf. + if ( ! empty( $src['ttf'] ) ) { + $src_ordered[] = array( + 'url' => $src['ttf'], + 'format' => 'truetype', + ); + } + + // Add eot. + if ( ! empty( $src['eot'] ) ) { + $src_ordered[] = array( + 'url' => $src['eot'], + 'format' => 'embedded-opentype', + ); + } + + // Add otf. + if ( ! empty( $src['otf'] ) ) { + $src_ordered[] = array( + 'url' => $src['otf'], + 'format' => 'opentype', + ); + } + $font_face['src'] = $src_ordered; + + return $font_face; + } + + /** + * Builds the font-family's CSS. + * + * @since 6.4.0 + * + * @param array $font_face Font face to process. + * @return string This font-family's CSS. + */ + private function build_font_face_css( array $font_face ) { + $css = ''; + + /* + * Wrap font-family in quotes if it contains spaces + * and is not already wrapped in quotes. + */ + if ( + str_contains( $font_face['font-family'], ' ' ) && + ! str_contains( $font_face['font-family'], '"' ) && + ! str_contains( $font_face['font-family'], "'" ) + ) { + $font_face['font-family'] = '"' . $font_face['font-family'] . '"'; + } + + foreach ( $font_face as $key => $value ) { + // Compile the "src" parameter. + if ( 'src' === $key ) { + $value = $this->compile_src( $value ); + } + + // If font-variation-settings is an array, convert it to a string. + if ( 'font-variation-settings' === $key && is_array( $value ) ) { + $value = $this->compile_variations( $value ); + } + + if ( ! empty( $value ) ) { + $css .= "$key:$value;"; + } + } + + return $css; + } + + /** + * Compiles the `src` into valid CSS. + * + * @since 6.4.0 + * + * @param array $value Value to process. + * @return string The CSS. + */ + private function compile_src( array $value ) { + $src = ''; + + foreach ( $value as $item ) { + $src .= ( 'data' === $item['format'] ) + ? ", url({$item['url']})" + : ", url('{$item['url']}') format('{$item['format']}')"; + } + + $src = ltrim( $src, ', ' ); + return $src; + } + + /** + * Compiles the font variation settings. + * + * @since 6.4.0 + * + * @param array $font_variation_settings Array of font variation settings. + * @return string The CSS. + */ + private function compile_variations( array $font_variation_settings ) { + $variations = ''; + + foreach ( $font_variation_settings as $key => $value ) { + $variations .= "$key $value"; + } + + return $variations; + } +} |