* Provides utility functions for working with font families.
* A class of utilities for working with the Font Library.
* These utilities may change or be removed in the future and are intended for internal use only.
* Adds surrounding quotes to font family names that contain special characters.
* It follows the recommendations from the CSS Fonts Module Level 4.
* @link https://www.w3.org/TR/css-fonts-4/#font-family-prop
* @param string $item A font family name.
* @return string The font family name with surrounding quotes, if necessary.
private static function maybe_add_quotes( $item ) {
// Matches strings that are not exclusively alphabetic characters or hyphens, and do not exactly follow the pattern generic(alphabetic characters or hyphens).
$regex = '/^(?!generic\([a-zA-Z\-]+\)$)(?!^[a-zA-Z\-]+$).+/';
if ( preg_match( $regex, $item ) ) {
$item = trim( $item, "\"'" );
return '"' . $item . '"';
* Sanitizes and formats font family names.
* - Applies `sanitize_text_field`.
* - Adds surrounding quotes to names containing any characters that are not alphabetic or dashes.
* It follows the recommendations from the CSS Fonts Module Level 4.
* @link https://www.w3.org/TR/css-fonts-4/#font-family-prop
* @see sanitize_text_field()
* @param string $font_family Font family name(s), comma-separated.
* @return string Sanitized and formatted font family name(s).
public static function sanitize_font_family( $font_family ) {
$output = sanitize_text_field( $font_family );
$formatted_items = array();
if ( str_contains( $output, ',' ) ) {
$items = explode( ',', $output );
foreach ( $items as $item ) {
$formatted_item = self::maybe_add_quotes( $item );
if ( ! empty( $formatted_item ) ) {
$formatted_items[] = $formatted_item;
return implode( ', ', $formatted_items );
return self::maybe_add_quotes( $output );
* Generates a slug from font face properties, e.g. `open sans;normal;400;100%;U+0-10FFFF`
* Used for comparison with other font faces in the same family, to prevent duplicates
* that would both match according the CSS font matching spec. Uses only simple case-insensitive
* matching for fontFamily and unicodeRange, so does not handle overlapping font-family lists or
* @link https://drafts.csswg.org/css-fonts/#font-style-matching
* @param array $settings {
* @type string $fontFamily Font family name.
* @type string $fontStyle Optional font style, defaults to 'normal'.
* @type string $fontWeight Optional font weight, defaults to 400.
* @type string $fontStretch Optional font stretch, defaults to '100%'.
* @type string $unicodeRange Optional unicode range, defaults to 'U+0-10FFFF'.
* @return string Font face slug.
public static function get_font_face_slug( $settings ) {
'unicodeRange' => 'U+0-10FFFF',
$settings = wp_parse_args( $settings, $defaults );
if ( function_exists( 'mb_strtolower' ) ) {
$font_family = mb_strtolower( $settings['fontFamily'] );
$font_family = strtolower( $settings['fontFamily'] );
$font_style = strtolower( $settings['fontStyle'] );
$font_weight = strtolower( $settings['fontWeight'] );
$font_stretch = strtolower( $settings['fontStretch'] );
$unicode_range = strtoupper( $settings['unicodeRange'] );
// Convert weight keywords to numeric strings.
$font_weight = str_replace( array( 'normal', 'bold' ), array( '400', '700' ), $font_weight );
// Convert stretch keywords to numeric strings.
$font_stretch_map = array(
'ultra-condensed' => '50%',
'extra-condensed' => '62.5%',
'semi-condensed' => '87.5%',
'semi-expanded' => '112.5%',
'extra-expanded' => '150%',
'ultra-expanded' => '200%',
$font_stretch = str_replace( array_keys( $font_stretch_map ), array_values( $font_stretch_map ), $font_stretch );
$slug_elements = array( $font_family, $font_style, $font_weight, $font_stretch, $unicode_range );
$slug_elements = array_map(
// Remove quotes to normalize font-family names, and ';' to use as a separator.
$elem = trim( str_replace( array( '"', "'", ';' ), '', $elem ) );
// Normalize comma separated lists by removing whitespace in between items,
// but keep whitespace within items (e.g. "Open Sans" and "OpenSans" are different fonts).
// CSS spec for whitespace includes: U+000A LINE FEED, U+0009 CHARACTER TABULATION, or U+0020 SPACE,
// which by default are all matched by \s in PHP.
return preg_replace( '/,\s+/', ',', $elem );
return sanitize_text_field( implode( ';', $slug_elements ) );
* Sanitizes a tree of data using a schema.
* The schema structure should mirror the data tree. Each value provided in the
* schema should be a callable that will be applied to sanitize the corresponding
* value in the data tree. Keys that are in the data tree, but not present in the
* schema, will be removed in the sanitized data. Nested arrays are traversed recursively.
* @param array $tree The data to sanitize.
* @param array $schema The schema used for sanitization.
* @return array The sanitized data.
public static function sanitize_from_schema( $tree, $schema ) {
if ( ! is_array( $tree ) || ! is_array( $schema ) ) {
foreach ( $tree as $key => $value ) {
// Remove keys not in the schema or with null/empty values.
if ( ! array_key_exists( $key, $schema ) ) {
$is_value_array = is_array( $value );
$is_schema_array = is_array( $schema[ $key ] ) && ! is_callable( $schema[ $key ] );
if ( $is_value_array && $is_schema_array ) {
if ( wp_is_numeric_array( $value ) ) {
// If indexed, process each item in the array.
foreach ( $value as $item_key => $item_value ) {
$tree[ $key ][ $item_key ] = isset( $schema[ $key ][0] ) && is_array( $schema[ $key ][0] )
? self::sanitize_from_schema( $item_value, $schema[ $key ][0] )
: self::apply_sanitizer( $item_value, $schema[ $key ][0] );
// If it is an associative or indexed array, process as a single object.
$tree[ $key ] = self::sanitize_from_schema( $value, $schema[ $key ] );
} elseif ( ! $is_value_array && $is_schema_array ) {
// If the value is not an array but the schema is, remove the key.
} elseif ( ! $is_schema_array ) {
// If the schema is not an array, apply the sanitizer to the value.
$tree[ $key ] = self::apply_sanitizer( $value, $schema[ $key ] );
// Remove keys with null/empty values.
if ( empty( $tree[ $key ] ) ) {
* Applies a sanitizer function to a value.
* @param mixed $value The value to sanitize.
* @param callable $sanitizer The sanitizer function to apply.
* @return mixed The sanitized value.
private static function apply_sanitizer( $value, $sanitizer ) {
if ( null === $sanitizer ) {
return call_user_func( $sanitizer, $value );
* Returns the expected mime-type values for font files, depending on PHP version.
* This is needed because font mime types vary by PHP version, so checking the PHP version
* is necessary until a list of valid mime-types for each file extension can be provided to
* the 'upload_mimes' filter.
* @return string[] A collection of mime types keyed by file extension.
public static function get_allowed_font_mime_types() {
$php_7_ttf_mime_type = PHP_VERSION_ID >= 70300 ? 'application/font-sfnt' : 'application/x-font-ttf';
'otf' => 'application/vnd.ms-opentype',
'ttf' => PHP_VERSION_ID >= 70400 ? 'font/sfnt' : $php_7_ttf_mime_type,
'woff' => PHP_VERSION_ID >= 80112 ? 'font/woff' : 'application/font-woff',
'woff2' => PHP_VERSION_ID >= 80112 ? 'font/woff2' : 'application/font-woff2',
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
