使用自定义代码更改WordPress中的语言

Question

I have site in WP that have multiple languages like (English,German and French).there url look like this :http://example.com(english). http://example.com/?lang=fr(french) and http://example.com/?lang=de(german) I am trying to change language before page loads.so i try some code on index.php but it creates issue. My code is :

$currentUrl = 'this is current page url';
 $store_code = "french";
switch ($store_code) { 
    case 'french':
       $_baseurl = $currentUrl."?lang=fr"; 

        echo "<script type='text/javascript'>window.location='{$_baseurl}'</script>";
        break;
case 'german':
       $_baseurl = $currentUrl."?lang=de"; 
        echo "<script type='text/javascript'>window.location='{$_baseurl}'</script>";
        break; 
case 'mandarin':
       $_baseurl = $currentUrl."?lang=zh"; 
        echo "<script type='text/javascript'>window.location='{$_baseurl}'</script>";
        break;   
    default:
       $_baseurl = $currentUrl; 
        echo "<script type='text/javascript'>window.location='{$_baseurl}'</script>";
        break;
}
Output.

It generate url like this with empty page.

http://example.com/?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr?lang=fr

Answer 1

I solved it using condition before the switch statment.It works

define('WP_USE_THEMES', true);
require("../app/Mage.php");
umask(0);
Mage::app('default');
$currentUrl = Mage::helper('core/url')->getCurrentUrl();
 $store_code = Mage::app()->getStore()->getCode();
if(Mage::getSingleton('core/session', array('name' => 'frontend'))->getData("foo") !='bar')
{

Mage::getSingleton('core/session')->setData("foo","bar");
switch ($store_code) { 
    case 'french':
       $_baseurl = $currentUrl."?lang=fr"; 
         echo "<script type='text/javascript'>window.location='{$_baseurl}'</script>";
        break;
case 'german':
       $_baseurl = $currentUrl."?lang=de"; 
         echo "<script type='text/javascript'>window.location='{$_baseurl}'</script>";
        break; 
case 'mandarin':
       $_baseurl = $currentUrl."?lang=zh"; 
        echo "<script type='text/javascript'>window.location='{$_baseurl}'</script>";
        break;   
    default:
       $_baseurl = $currentUrl; 
         echo "<script type='text/javascript'>window.location='{$_baseurl}'</script>";
        break;
}
}

While on Magento side i set the session before the layout load event like this.

Mage::getSingleton('core/session')->setData("foo","magento");