多语言网站 - PHP类 - 正确的方法是什么？ [关闭]

I have just starter to use PHP OOP and I would like to write a class to make a multi-language website. I started from this but I wanted to use OOP so I came up with this:

Language.php

<?php

class Language {

    private $UserLng;
    private $langSelected;
    public $lang = array();


    public function __construct($userLanguage){

        $this->UserLng = $userLanguage;
    }

    public function userLanguage(){

        switch($this->UserLng){
            /*
            ------------------
            Language: English
            ------------------
            */
            case "en":
                $lang['PAGE_TITLE'] = 'My website page title';
                $lang['HEADER_TITLE'] = 'My website header title';
                $lang['SITE_NAME'] = 'My Website';
                $lang['SLOGAN'] = 'My slogan here';
                $lang['HEADING'] = 'Heading';

                // Menu

                $lang['MENU_LOGIN'] = 'Login';
                $lang['MENU_SIGNUP'] = 'Sign up';
                $lang['MENU_FIND_RIDE'] = 'Find Ride';
                $lang['MENU_ADD_RIDE'] = 'Add Ride';
                $lang['MENU_LOGOUT'] = 'Logout';

                return $lang;
                break;

                /*
                ------------------
                Language: Italian
                ------------------
                */

            case "it":
                $lang['PAGE_TITLE'] = 'Il titolo della mia pagina';
                $lang['HEADER_TITLE'] = 'Il mio titolo';
                $lang['SITE_NAME'] = 'Il nome del mio sito';
                $lang['SLOGAN'] = 'Uno slogan';
                $lang['HEADING'] = 'Heading';

                // Menu

                $lang['MENU_LOGIN'] = 'Entra';
                $lang['MENU_SIGNUP'] = 'Registrati';
                $lang['MENU_FIND_RIDE'] = 'Trova gruppi';
                $lang['MENU_ADD_RIDE'] = 'Aggiungi gruppo';
                $lang['MENU_LOGOUT'] = 'Esci';

                return $lang;
                break;

        }
    }
}

index.php

<?php 
$lang = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2);//Detecting Default Browser language
$language = New Language($lang);
$langArray = array();
$langArray =  $language->userLanguage();
?>

<div class="cssmenu">
    <ul>
        <li> class="active"><a href="/login"><?php echo $langArray['MENU_LOGIN']?></a></li>                                                                                         
        <li><a href="/rides"><?php echo $langArray['MENU_FIND_RIDE']?></a></li>                                               
        <li><a  id ="btnShow"><?php echo $langArray['MENU_ADD_RIDE']?></a></li>                                              
        <li><a href="/logout.php"><?php echo $langArray['MENU_LOGOUT']?> </a></li>                                                   
        <li><a href="/register"><?php echo $langArray['MENU_SIGNUP']?></a></li>
    </ul>
</div>

While this perfectly works, I am not sure this is the correct way to do it. I didn't find many tutorials on how to do this using OOP so I have the following doubts:

1. Is this a correct way to do it?
2. is this code maintainable?
3. would it make more sense to create a table in the database with all the different languages?
4. I am still struggling to understand "abstract classes". Would this be the case to create an abstract class language.php and then extend(I hope this is the correct terminology) that class with other languages class (english.php, italian.php etc).

You are very much on track, except for one bit, your data and code are intertwined, which is not a good form of design. Different people use various approaches for handling i18N. I prefer using .ini files, you can have the data in different INI files and even add sections if you want. Using your example, you can do:

-- en.ini

PAGE_TITLE = 'My website page title'
HEADER_TITLE = 'My website header title'
SITE_NAME' = 'My Website'
SLOGAN = 'My slogan here'
HEADING = 'Heading'

-- it.ini

PAGE_TITLE = 'Il titolo della mia pagina'
HEADER_TITLE = 'Il mio titolo'
SITE_NAME = 'Il nome del mio sito'
SLOGAN = 'Uno slogan'
HEADING = 'Heading'

Then your code can be rewritten as :

<?php

class Language {

private $UserLng;
private $langSelected;
public $lang = array();


public function __construct($userLanguage){

    $this->UserLng = $userLanguage;
    //construct lang file
    $langFile = '/path/to/ini/files/'. $this->UserLng . '.ini';
    if(!file_exists($langFile)){
        throw new Execption("Language could not be loaded"); //or default to a language
    }

    $this->lang = parse_ini_file($langFile);
}

public function userLanguage(){
    return $this->lang;
}

}

This is the right way.

But, you can create some language files

- english.php
define('ABOUT_US', 'About us');
....
- french.php
....

it may be more optimizer.

Create a table in the database with all the different languages is an idea (vbulletin use this way), but it may take so much system resource.