We will now discuss the internationalization (i18n) of our theme. The objective is to ensure that our theme adapts to the language chosen by the site administrator. To translate a theme or WordPress plugin use the gettext library.

We will start by specifying the domain associated with our theme / plugin:

/ *
Theme Name: My theme
Text Domain: montheme
* /

Then, we will use the localization functions in our theme:

Parameter page
// will become

It will then be necessary to use the POEdit software in order to extract the strings to translate into a .pot (if we are using a template) or .po file that we will place in a specific folder for our theme.

Finally, we will tell WordPress how to load translations for our domain

add_action ('after_setup_theme', function () {
    load_theme_textdomain ('montheme', get_template_directory (). '/ languages');
});