<?php
/**
* Locale API: WP_Locale_Switcher class
*
* @package WordPress
* @subpackage i18n
* @since 4.7.0
*/
/**
* Core class used for switching locales.
*
* @since 4.7.0
*/
class WP_Locale_Switcher {
/**
* Locale stack.
*
* @since 4.7.0
* @var string[]
*/
private $locales = array();
/**
* Original locale.
*
* @since 4.7.0
* @var string
*/
private $original_locale;
/**
* Holds all available languages.
*
* @since 4.7.0
* @var array An array of language codes (file names without the .mo extension).
*/
private $available_languages = array();
/**
* Constructor.
*
* Stores the original locale as well as a list of all available languages.
*
* @since 4.7.0
*/
public function __construct() {
$this->original_locale = determine_locale();
$this->available_languages = array_merge( array( 'en_US' ), get_available_languages() );
}
/**
* Initializes the locale switcher.
*
* Hooks into the {@see 'locale'} filter to change the locale on the fly.
*
* @since 4.7.0
*/
public function init() {
add_filter( 'locale', array( $this, 'filter_locale' ) );
}
/**
* Switches the translations according to the given locale.
*
* @since 4.7.0
*
* @param string $locale The locale to switch to.
* @return bool True on success, false on failure.
*/
public function switch_to_locale( $locale ) {
$current_locale = determine_locale();
if ( $current_locale === $locale ) {
return false;
}
if ( ! in_array( $locale, $this->available_languages, true ) ) {
return false;
}
$this->locales[] = $locale;
$this->change_locale( $locale );
/**
* Fires when the locale is switched.
*
* @since 4.7.0
*
* @param string $locale The new locale.
*/
do_action( 'switch_locale', $locale );
return true;
}
/**
* Restores the translations according to the previous locale.
*
* @since 4.7.0
*
* @return string|false Locale on success, false on failure.
*/
public function restore_previous_locale() {
$previous_locale = array_pop( $this->locales );
if ( null === $previous_locale ) {
// The stack is empty, bail.
return false;
}
$locale = end( $this->locales );
if ( ! $locale ) {
// There's nothing left in the stack: go back to the original locale.
$locale = $this->original_locale;
}
$this->change_locale( $locale );
/**
* Fires when the locale is restored to the previous one.
*
* @since 4.7.0
*
* @param string $locale The new locale.
* @param string $previous_locale The previous locale.
*/
do_action( 'restore_previous_locale', $locale, $previous_locale );
return $locale;
}
/**
* Restores the translations according to the original locale.
*
* @since 4.7.0
*
* @return string|false Locale on success, false on failure.
*/
public function restore_current_locale() {
if ( empty( $this->locales ) ) {
return false;
}
$this->locales = array( $this->original_locale );
return $this->restore_previous_locale();
}
/**
* Whether switch_to_locale() is in effect.
*
* @since 4.7.0
*
* @return bool True if the locale has been switched, false otherwise.
*/
public function is_switched() {
return ! empty( $this->locales );
}
/**
* Filters the locale of the WordPress installation.
*
* @since 4.7.0
*
* @param string $locale The locale of the WordPress installation.
* @return string The locale currently being switched to.
*/
public function filter_locale( $locale ) {
$switched_locale = end( $this->locales );
if ( $switched_locale ) {
return $switched_locale;
}
return $locale;
}
/**
* Load translations for a given locale.
*
* When switching to a locale, translations for this locale must be loaded from scratch.
*
* @since 4.7.0
*
* @global Mo[] $l10n An array of all currently loaded text domains.
*
* @param string $locale The locale to load translations for.
*/
private function load_translations( $locale ) {
global $l10n;
$domains = $l10n ? array_keys( $l10n ) : array();
load_default_textdomain( $locale );
foreach ( $domains as $domain ) {
if ( 'default' === $domain ) {
continue;
}
unload_textdomain( $domain );
get_translations_for_domain( $domain );
}
}
/**
* Changes the site's locale to the given one.
*
* Loads the translations, changes the global `$wp_locale` object and updates
* all post type labels.
*
* @since 4.7.0
*
* @global WP_Locale $wp_locale WordPress date and time locale object.
*
* @param string $locale The locale to change to.
*/
private function change_locale( $locale ) {
// Reset translation availability information.
_get_path_to_translation( null, true );
$this->load_translations( $locale );
$GLOBALS['wp_locale'] = new WP_Locale();
/**
* Fires when the locale is switched to or restored.
*
* @since 4.7.0
*
* @param string $locale The new locale.
*/
do_action( 'change_locale', $locale );
}
}