load_muplugin_textdomain() │ WP 3.0.0

Load the translated strings for a plugin residing in the mu-plugins directory.

Uses: load_textdomain()

No Hooks.

Return

true|false. True when textdomain is successfully loaded, false otherwise.

Usage

load_muplugin_textdomain( $domain, $mu_plugin_rel_path );
$domain(string) (required)
Text domain. Unique identifier for retrieving translated strings.
$mu_plugin_rel_path(string)
Relative to WPMU_PLUGIN_DIR directory in which the .mo file resides.
Default: empty string

Examples

0

#1 Register a translation file for the MU plugin

The translation file must be in the plugin directory and must be named like: my-plugin-fr_FR.mo.

add_action( 'muplugins_loaded', 'myplugin_init' );

function myplugin_init(){
	load_muplugin_textdomain( 'my-plugin', dirname( plugin_basename( __FILE__ ) ) ); 
}
0

#2 If you want to place the .mo file in the subfolder lang:

We may change the translation file place. For example, let's place it into the lang subfolder of the plugin. The file must be named like: my-plugin-ru_RU.mo.

add_action( 'muplugins_loaded', 'myplugin_init' );

function myplugin_init() {
	 load_muplugin_textdomain( 'my-plugin', dirname( plugin_basename( __FILE__ ) ) . '/lang/' );
}

Notes

  • Global. WP_Textdomain_Registry. $wp_textdomain_registry WordPress Textdomain Registry.
  • Global. Array<String,. WP_Translations|NOOP_Translations> $l10n An array of all currently loaded text domains.

Changelog

Since 3.0.0 Introduced.
Since 4.6.0 The function now tries to load the .mo file from the languages directory first.
Since 6.7.0 Translations are no longer immediately loaded, but handed off to the just-in-time loading mechanism.

load_muplugin_textdomain() code WP 6.8

wp-includes/l10n.php 
function load_muplugin_textdomain( $domain, $mu_plugin_rel_path = '' ) {
	/** @var WP_Textdomain_Registry $wp_textdomain_registry */
	/** @var array<string, WP_Translations|NOOP_Translations> $l10n */
	global $wp_textdomain_registry, $l10n;

	if ( ! is_string( $domain ) ) {
		return false;
	}

	$path = WPMU_PLUGIN_DIR . '/' . ltrim( $mu_plugin_rel_path, '/' );

	$wp_textdomain_registry->set_custom_path( $domain, $path );

	// If just-in-time loading was triggered before, reset the entry so it can be tried again.
	if ( isset( $l10n[ $domain ] ) && $l10n[ $domain ] instanceof NOOP_Translations ) {
		unset( $l10n[ $domain ] );
	}

	return true;
}

textdomain (mo po files)

localize (l10n i18n Internationalization localization)

Localization