load_plugin_textdomain( string $domain, string $deprecated = false, string $plugin_rel_path = false )

Loads a plugin’s translated strings.


Description

If the path is not given then it will be the root of the plugin directory.

The .mo file should be named based on the text domain with a dash, and then the locale exactly.


Parameters

$domain

(Required) Unique identifier for retrieving translated strings

$deprecated

(Optional) Use the $plugin_rel_path parameter instead.

Default value: false

$plugin_rel_path

(Optional) Relative path to WP_PLUGIN_DIR where the .mo file resides.

Default value: false


Return

(bool) True when textdomain is successfully loaded, false otherwise.


Source

File: wp-includes/l10n.php

function load_plugin_textdomain( $domain, $deprecated = false, $plugin_rel_path = false ) {
	/**
	 * Filters a plugin's locale.
	 *
	 * @since WP-3.0.0
	 *
	 * @param string $locale The plugin's current locale.
	 * @param string $domain Text domain. Unique identifier for retrieving translated strings.
	 */
	$locale = apply_filters( 'plugin_locale', is_admin() ? get_user_locale() : get_locale(), $domain );

	$mofile = $domain . '-' . $locale . '.mo';

	// Try to load from the languages directory first.
	if ( load_textdomain( $domain, WP_LANG_DIR . '/plugins/' . $mofile ) ) {
		return true;
	}

	if ( false !== $plugin_rel_path ) {
		$path = WP_PLUGIN_DIR . '/' . trim( $plugin_rel_path, '/' );
	} elseif ( false !== $deprecated ) {
		_deprecated_argument( __FUNCTION__, 'WP-2.7.0' );
		$path = ABSPATH . trim( $deprecated, '/' );
	} else {
		$path = WP_PLUGIN_DIR;
	}

	return load_textdomain( $domain, $path . '/' . $mofile );
}


Changelog

Changelog
Version Description
WP-4.6.0 The function now tries to load the .mo file from the languages directory first.
WP-1.5.0 Introduced.