WP_Locale_Switcher

15#[AllowDynamicProperties]16class WP_Locale_Switcher {17	/**18	 * Locale switching stack.19	 *20	 * @since 6.2.021	 * @var array22	 */23	private $stack = array();24 25	/**26	 * Original locale.27	 *28	 * @since 4.7.029	 * @var string30	 */31	private $original_locale;32 33	/**34	 * Holds all available languages.35	 *36	 * @since 4.7.037	 * @var string[] An array of language codes (file names without the .mo extension).38	 */39	private $available_languages;40 41	/**42	 * Constructor.43	 *44	 * Stores the original locale as well as a list of all available languages.45	 *46	 * @since 4.7.047	 */48	public function __construct() {49		$this->original_locale     = determine_locale();50		$this->available_languages = array_merge( array( 'en_US' ), get_available_languages() );51	}52 53	/**54	 * Initializes the locale switcher.55	 *56	 * Hooks into the {@see 'locale'} and {@see 'determine_locale'} filters57	 * to change the locale on the fly.58	 *59	 * @since 4.7.060	 */61	public function init() {62		add_filter( 'locale', array( $this, 'filter_locale' ) );63		add_filter( 'determine_locale', array( $this, 'filter_locale' ) );64	}65 66	/**67	 * Switches the translations according to the given locale.68	 *69	 * @since 4.7.070	 *71	 * @param string    $locale  The locale to switch to.72	 * @param int|false $user_id Optional. User ID as context. Default false.73	 * @return bool True on success, false on failure.74	 */75	public function switch_to_locale( $locale, $user_id = false ) {76		$current_locale = determine_locale();77		if ( $current_locale === $locale ) {78			return false;79		}80 81		if ( ! in_array( $locale, $this->available_languages, true ) ) {82			return false;83		}84 85		$this->stack[] = array( $locale, $user_id );86 87		$this->change_locale( $locale );88 89		/**90		 * Fires when the locale is switched.91		 *92		 * @since 4.7.093		 * @since 6.2.0 The `$user_id` parameter was added.94		 *