WordPress/wp-includes/class-wp-locale-switcher.php
Pascal Birchler bb9f57429a I18N: Introduce WP_Textdomain_Registry to store text domains and their language directory paths.
Previously, when using `switch_to_locale()` all current loaded text domains were unloaded and added to the `$l10n_unloaded` global. This prevented the just-in-time loading for text domains after a switch. The just-in-time loading was also only possible if the translations were stored in `WP_LANG_DIR`. Both issues have been fixed.

* Adds `WP_Textdomain_Registry` to keep track of the language directory paths for all plugins and themes.
* Updates all `load_*_textdomain()`  functions to store the path in `WP_Textdomain_Registry`.
* Adds `$locale` parameter to `load_textdomain()` to specify the locale the translation file is for.
* Adds `$reloadable` parameter to `unload_textdomain()` to define whether a text domain can be loaded just-in-time again. This is used by `WP_Locale_Switcher::load_translations()`.
* Extends `_load_textdomain_just_in_time()` to also support text domains of plugins and themes with custom language directories.
* Fixes the incorrect `test_plugin_translation_after_switching_locale_twice()` test which should have caught this issue earlier.
* Adds a new test plugin and theme to test the loading of translations with a custom language directory.
* Deprecates the now unused and private `_get_path_to_translation()` and `_get_path_to_translation_from_lang_dir()` functions.

Previously added in [49236] and reverted in [49236] to investigate concerns which are now addressed here.

Props yoavf, swissspidy, dd32, ocean90.
See #26511.
Fixes #39210.
Built from https://develop.svn.wordpress.org/trunk@53874


git-svn-id: http://core.svn.wordpress.org/trunk@53433 1a063a9b-81f0-0310-95a4-ce76da25c4cd
2022-08-11 12:39:12 +00:00

240 lines
5.0 KiB
PHP

<?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 ) {
// The default text domain is handled by `load_default_textdomain()`.
if ( 'default' === $domain ) {
continue;
}
// Unload current text domain but allow them to be reloaded
// after switching back or to another locale.
unload_textdomain( $domain, true );
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 ) {
global $wp_locale;
$this->load_translations( $locale );
$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 );
}
}