How to make a multi country web site? (Best practices)

[eluser]Phil Sturgeon[/eluser]
Have just finished a hook that does exactly this.

2x CI config variables.
- Supported languages = array('EN' => English, 'FR' => French, etc)
- Default language = 'EN'

1x Hook entry in config/hooks.php

Code:

$hook['pre_controller'] = array(
'function' => 'PickLanguage',
'filename' => 'pick_language.php',
'filepath' => 'hooks',
);

1x Hook file

Code:

<?php if (!defined('BASEPATH')) exit('No direct script access allowed');

session_start();

function PickLanguage() {
    require_once(APPPATH.'/config/languages.php');
      
    // Lang set in URL via ?lang=something
    if(!empty($_GET['lang']))
    {
        // Uppercase and only 2 characters long
        $lang = strtoupper(substr($_GET['lang'], 0, 2));
        $_SESSION['lang_code'] = $lang;
    }
    
    // Lang has already been set and is stored in a session
    elseif( !empty($_SESSION['lang_code']) )
    {
        $lang = $_SESSION['lang_code'];
    }
    
    // Still no Lang. Lets try some browser detection then
    else
    {
        $accept_langs = $this->obj->input->server('HTTP_ACCEPT_LANGUAGE');
        
        if (!empty( $accept_langs ))
        {
            // explode languages into array
            $accept_langs = explode(',', $accept_langs);
        
            log_message('debug', 'Checking browser languages: '.implode(', ', $accept_langs));
            
            // Check them all, until we find a match
            foreach ($accept_langs as $lang)
            {
                // Turn en-gb into EN
                $lang = strtoupper(substr($lang, 0, 2));
                
                // Check its in the array. If so, break the loop, we have one!
                if(in_array($lang, array_keys($config['supported_languages'])))
                {
                    break;
                }
            }
        }

        // Still not found a lang, lets just use the default
        if(empty($lang))
        {
            $lang = $config['default_language'];
        }
        
        // Whatever we decided the lang was, save it for next time to avoid working it out again
        $_SESSION['lang_code'] = $lang;
    }
    
    // Check the provided lang is available
    if(!in_array($lang, array_keys($config['supported_languages'])))
    {
        exit('This language doesnt exist boso!');
    }

    // Load CI config class
    $CI_config =& load_class('Config');

    // Set the language config. Getting 'English' from the array by calling it from its key of 'EN', and make it lowercase so CI looks for 'english'
    $CI_config->set_item('language', $config['supported_languages'][$lang]);

    // Sets a constant to use throughout ALL of CI.
    define('DEFAULT_LANGUAGE', $lang);
}

?>

Then, you can use DEFAULT_LANGUAGE in all your models and everywhere else in CI to reference your lang specific data. Works beautifully!

Edit - 07/01/09: Added in browser detection support.