Question

I use the following code to change the language in my website:

<?php
session_start();
header('Cache-control: private'); // IE 6 FIX

function get_lang(){
    if(!empty($_GET['lang'])) return $_GET['lang'];
    if(!empty($_SESSION['lang'])) return $_SESSION['lang'];
    if(!empty($_COOKIE['lang'])) return $_COOKIE['lang'];
    return 'en';
}

function set_lang($lang){
    setcookie("lang", $lang, time() + (3600 * 24 * 30));
    $_SESSION['lang'] = $lang;
}

function get_lang_file($lang){
    $lang_file = "languages/lang.$lang.php";
    if(file_exists($lang_file)) return $lang_file;
    if($lang_file = get_lang_file('en')) return $lang_file;
    return false;
}

//translation helper function
function l($string){
    static $translation;

    if(!isset($translation)){
        $lang = get_lang();
        $lang_file = get_lang_file($lang);
        if($lang_file) set_lang($lang);
        $translation = include $lang_file;
    }

    return $translation[$string];
}

?>

I want to add a Javascript file according to the value of one of the variables, in this case $lang_file:

    <?php if($lang_file=='lang.en.php') {echo ' <script type="text/javascript" src="scripts/jquery-validate/val-en.js"></script>';} ?>
    <?php if($lang_file=='lang.es.php') {echo ' <script type="text/javascript" src="scripts/jquery-validate/val-es.js"></script>';} ?>
    <?php if($lang_file=='lang.tw.php') {echo ' <script type="text/javascript" src="scripts/jquery-validate/val-tw.js"></script>';} ?>
    <?php if($lang_file=='lang.cn.php') {echo ' <script type="text/javascript" src="scripts/jquery-validate/val-cn.js"></script>';} ?>

But it doesn’t work because all the variables become NULL at the end (but the code works).

I tested it with this and it says NULL NULL NULL NULL:

var_dump($translation);
var_dump($lang);
var_dump($string);
var_dump($lang_file);

Any suggestions?

EDIT: sample of the Javascripts I’m calling (val-xx.js):

$(document).ready(function(){
    $("#sendmail").validate({
        rules: {
            FieldData0: {
                required: true
            },
            FieldData1: {
                required: true,
                email: true
            },
            FieldData2: {
                required: true
            }
        },
        messages: {
            FieldData0: {
                required: "Please enter your name"
            },
            FieldData1: {
                required: "Please enter your email address"
            },
            FieldData2: {
                required: "Please enter a message"
            }
        }
    });
})

a sample of a lang.$lang.php file:

<?php
return array(
'tagline_h2' => '我创造简单...',

(and so on)

Answer 1

It looks like you’re a victim of variable scope. If you want to reference a variable defined in a function you have to declare it as global. For example:

$lang_file = "languages/lang.en.php" //default
function get_lang_file($lang){
    global $lang_file;
    $lang_file = "languages/lang.$lang.php";
    if(file_exists($lang_file)) return $lang_file;
    if($lang_file = get_lang_file('en')) return $lang_file;
    return false;
}

OR (more properly), just use the functions return value:

if(get_lang_file($mylang) == 'blah')

versus

if($lang_file == 'blah')