Best way to internationalize simple PHP website

Although ext/gettext and ext/intl are both related to i18 (internationalization), gettext deals with translation while intl deals with internationalizing things like number and date display, sorting orders and transliteration. So you’d actually need both for a complete i18-solution. Depending on your needs you may come up with an home-brew solution relying on the extensions mentioned above or your use components provided by some framework:

• Translation
  • Symfony 2 Translation component: https://github.com/symfony/Translation
  • Zend Framework Zend_Translate
• Internationalization
  • Zend Framework Zend_Locale

If you only need translation and the site is simple enough, perhaps your simple solution (reading a translation configuration file into an PHP array, using a simple function to retrieve a token) might be the easiest.

The most simple solution I can think of is:

$translation = array(
    'Hello world!' => array(
        'fr' => 'Bonjour tout le monde!',
        'de' => 'Hallo Welt!'
    )
);

if (!function_exists('gettext')) {
    function _($token, $lang = null) {
        global $translation;
        if (   empty($lang)
            || !array_key_exists($token, $translation)
            || !array_key_exists($lang, $translation[$token])
        ) {
            return $token;
        } else {
            return $translation[$token][$lang];
        }
    }
}

echo _('Hello World!');