When a user opens the homepage of an international site, it should propose localized content matching its language and area.
This post describes how to detect a user’s language and region in PHP.
Prerequisites
- Have a server running PHP (see Install and set up a web server on Debian or Ubuntu Linux).
- Install locales (see Useful commands for Debian or Ubuntu Linux).
The locales
The locales are predefined values corresponding to a language and a region.
For example:
en_US for english in the United States fr_FR for french in France fr_CA for french in Canada
The locales allow to handle localized content (translations, formatted dates, numeric and monetary formats…).
Detect a user’s locale
The list of a user’s preferred locales is provided by its browser in $ _SERVER [‘HTTP_ACCEPT_LANGUAGE’].
function DetectLocale() {
$Language = str_replace('-', '_', $_SERVER['HTTP_ACCEPT_LANGUAGE']);
if (preg_match('/[a-z]{2}_[A-Z]{2}/', $Language, $MatchesArray)) {
return $MatchesArray[0]; // Preferred locale
}
return 'en_US'; // Default locale
}
Once the locale detected, it is possible to:
- Keep locale in a cookie with the setcookie function.
- Redirect the user to a localized part of the site with the header function. For example header(‘Location: http://en-us.mydomain.com’); or header(‘Location: http://mydomain.com/en-us/’);
- Set the locale used by PHP with the setlocale function.
- Show formatted dates with the strftime function.
- Obtain localized information about numeric and monetary formats with the localeconv function.