Detect browser language and redirect

Question

I am using Wordpress and wanted to redirect my page to the "/br/","/es/" versions, when the browser language is one of these and when it is not it stay in the default page, that is the ". with".

I tried to use that code, but it didn’t work:

function idiomaUsuario(){
    $idioma = substr($_SERVER["HTTP_ACCEPT_LANGUAGE"], 0, 2);
    return $idioma; 
}


    function redirecionaPaginaIdioma($idioma){
        switch($idioma){
            case 'pt': //Caso seja português
                header('Location: http://www.seusite.com.br/pt/');
                break;
            case 'es': //Caso seja espanhol
                header('Location: http://www.seusite.com.br/es/');
                break;
            default:
                header('Location: http://www.seusite.com.br/en/');
                break;
        }
    }

I don’t know if it changes anything do this with PHP or JS, but any solution serves.

Note: I put this code at the beginning of Index.php of the Wordpress theme.

Answer 1

This solution posed in the question does not go very well by the way in which the HTTP_ACCEPT_LANGUAGE works. It returns a string in this format:

en-US,en;q=0.8,pt-BR;q=0.6,pt;q=0.4

indicating the user’s preference order for the parameter q= (technically called quality factor), and as you may notice, you may have more than one language (general or regionalized) in the list.

The following is interpreted in the example line: "I accept US English, and if not, "general" English (weight 0.8). In the absence of these, it may be Brazilian Portuguese (weight 0.6), and finally "general Portuguese" (weight 0.4).

The problem is that there is no guarantee that this list will come in order of importance. I’ve never seen out of order, but the specification clearly states that the order is given by quality factor and not by textual position.

Also, it may happen that the first one on the list is a language that you don’t have available, but the second or third one might be. In this case, as the question code only takes the first one on the list, there is no way it will solve your problem.

That said, let’s get to the solution.

Function to do the parse string

Based on what I mentioned at the beginning of the answer, I have worked out a basic function that can serve as a starting point for what you need:

$acceptLanguage = $_SERVER['HTTP_ACCEPT_LANGUAGE'];
$langs = array();
foreach( explode(',', $acceptLanguage) as $lang) {
    $lang = explode(';q=', $lang);
    $langs[$lang[0]] = count($lang)>1?floatval($lang[1]):1;
}
arsort($langs);

Basically what she does is break the string original by commas, using the explode, and keeping in a array in language=>weight format. Once this is done, the arsort orders our list starting at the highest weight and going down to the lowest.

Once the parse, we need to see what we have available to serve the user. For this part, here is a solution:

$ourLanguages = array('pt-BR'=>'pt','pt'=>'pt','es'=>'es');

$choice = 'pt'; //Caso nenhuma outra sirva
foreach($langs as $lang=>$q) {
   if(in_array($lang,array_flip($ourLanguages))) {
      $choice=$ourLanguages[$lang];
      break;
   }
}

header("Location: http://www.example.com/$choice/");

The working principle is simple, we test one by one of the client’s languages until we find one that fits. To completely solve the problem, we use the format linguagem do cliente => nosso mapeamento, so you can say that pt-BR should be understood simply as pt, which is the part you use in the URL.

You can see a functional example on IDEONE.

_{Just for the record, there’s a PECL extension that handles this, but I’d say it’s more of a cast than our solution: http://php.net/http_negotiate_language}

Answer 2

You can get this setting using the class Locale library lntl, which is available from php5.3.

<?php

echo 'Disponiveis: '. $_SERVER['HTTP_ACCEPT_LANGUAGE'] .'<br>';
$lang = substr(Locale::acceptFromHttp($_SERVER['HTTP_ACCEPT_LANGUAGE']), 0, 2);

if($lang === 'pt'){
    echo 'Olá amigo';
}else if($lang == 'es'){
    echo 'Hola amigo';  
}else if($lang == 'en'){
        echo 'Hello friend';
}else if($lang == 'de'){
    echo 'hallo Freund';
}

You can use firefox as a test to change your language preference. Go to the Tools>options> content tab menu. In languages change language leave at the top by Spanish exem and see how the code works.

Example - Phpfiddle

Answer 3

There is a very good translation plugin for Wordpress called Transposh.

With it is possible:

• Dynamically translate any page of the site using Google, Bing, Yandex among others
• use an existing page as a translation of another
• Mark not to translate a particular excerpt or even the entire page, avoiding machine translation
• Edit the translation directly into the site’s final HTML.
• Display language flags allowing the user to view the site in any language
• Generate links in the domain style/xx/page where xx stands for language as shown in HTTP_ACCEPT_LANGUAGE

More details on http://transposh.org/pt/faq/

I also recommend to make a donation if you like the plugin