load_plugin_textdomain doestn't work with add_action plugins_loaded

Question

I am trying to load localization for my plugin.

There is directory called languages in my plugin folder with .po and .mo files inside of it.

I have the following code in the plugin main file:

<?php
function myplugin_lang_init() {
    $domain = 'mydomain';
    // The "plugin_locale" filter is also used in load_plugin_textdomain()
    $locale = apply_filters('plugin_locale', get_locale(), $domain);
    load_textdomain($domain, WP_LANG_DIR.'/plugins/'.$domain.'-'.$locale.'.mo');
    load_plugin_textdomain($domain, FALSE, dirname(plugin_basename(__FILE__)).'/languages/');
}
// myplugin_lang_init(); // That works
add_action('plugins_loaded', 'myplugin_lang_init'); // I don't know why but it doesn't work

That works only if I call myplugin_lang_init() directly, but doest't work if I do add_action('plugins_loaded', 'myplugin_lang_init').

Exactly the same code always was working perfectly in other plugins I've ever developed.

Could you please have a look at it? Have I missed something?

Thanks in advance.

Answer 1

In case of someone see this,

Following worked for me with 4 changes :

1. translated files only in plugin lang dir
2. using "init" hook instead of "plugins_loaded" and be sure strings to translate are loaded after this one
3. using get_user_locale() to be sure to show the right language for logged users (if not logged, this return get_locale())
4. translations files names are like this : en_US.mo/po, fr_FR.mo/po...

function myplugin_lang_init() {
    $domain = 'mydomain';
    $plugin_dir_lang = plugin_dir_path( __FILE__ ) . 'languages'; // assume that current php file is in plugin root directory
    // The "plugin_locale" filter is also used in load_plugin_textdomain()
    $locale = apply_filters('plugin_locale', get_user_locale(), $domain); // use get_user_locale() instead of get_locale()
    load_textdomain($domain, $plugin_dir_lang . '/' . $locale . '.mo');
    load_plugin_textdomain($domain, FALSE, $plugin_dir_lang);
}
// myplugin_lang_init(); // That works
add_action('init', 'myplugin_lang_init'); // use init instead of plugins_loaded