wp-includes/l10n/class-wp-translation-controller.php:201Unloads all translation files for a given text domain.
$textdomainstringoptional'default'$localestringoptionalnullbool public function unload_textdomain( string $textdomain = 'default', ?string $locale = null ): bool { $unloaded = false; if ( null !== $locale ) { if ( isset( $this->loaded_translations[ $locale ][ $textdomain ] ) ) { $unloaded = true; foreach ( $this->loaded_translations[ $locale ][ $textdomain ] as $moe ) { unset( $this->loaded_files[ $moe->get_file() ][ $locale ][ $textdomain ] ); } } unset( $this->loaded_translations[ $locale ][ $textdomain ] ); return $unloaded; } foreach ( $this->loaded_translations as $l => $domains ) { if ( ! isset( $domains[ $textdomain ] ) ) { continue; } $unloaded = true; foreach ( $domains[ $textdomain ] as $moe ) { unset( $this->loaded_files[ $moe->get_file() ][ $l ][ $textdomain ] ); } unset( $this->loaded_translations[ $l ][ $textdomain ] ); } return $unloaded; }Introduced in 6.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/l10n/class-wp-translation-controller.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.