Internationalization

Define the text domain in the style.css of the theme.

/*!
Theme Name: WPFlames
Text Domain: wpflames
Theme URI: http://gaborflamich.com/
Author: Gabor Flamich

You should use escaping functions for sanitizing data:

<h1><?php esc_html_e( 'Front Page', 'wpflames' ); ?></h1>

Instead of this

<h1>Front Page</h1>

Generating POT file with WP-CLI

wp i18n make-pot wpflames-theme

Load textdomain in functions.php

// =========================================================================
// Load textdomain for internationalization
// =========================================================================
function wpflames_load_theme_textdomain() {
    load_theme_textdomain( 'wpflames', get_template_directory() . '/languages' );
}
add_action( 'after_setup_theme', 'wpflames_load_theme_textdomain' );

Poedit

You can also use Poedit locally for translating.

POT (Portable Object Template) files

This file contains the original strings (in English) in your plugin/theme

#: plugin-name.php:123
msgid "Page Title"
msgstr ""

PO (Portable Object) files

You can take the POT file and translate the msgstr sections in your own language. The result is a PO file with the same format as a POT, but with translations and some specific headers. There is one PO file per language.

MO (Machine Object) files

MO file is a “compiled” version of the PO file.