<?php

$your_client_id = '0750facb-bb29-43b4-a629-42603c2efbea';
$your_secret = 'I3GDuMftmn4pTeUTiJgJp0VGNbEkfDbBgwFDC7eb6E0';



    class BingTranslation
    {
        public $clientID;
        public $clientSecret;

        public function __construct($cid, $secret)
        {
            $this->clientID = $cid;
            $this->clientSecret = $secret;
        }

        public function get_access_token()
        {
            //if access token is not expired and is stored in COOKIE
            if(isset($_COOKIE['bing_access_token']))
                return $_COOKIE['bing_access_token'];

            // Get a 10-minute access token for Microsoft Translator API.
            $url = 'https://datamarket.accesscontrol.windows.net/v2/OAuth2-13';
            $postParams = 'grant_type=client_credentials&client_id='.urlencode($this->clientID).
            '&client_secret='.urlencode($this->clientSecret).'&scope=http://api.microsofttranslator.com';

            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $postParams);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
            $rsp = curl_exec($ch);
            $rsp = json_decode($rsp);
            $access_token = $rsp->access_token;

            setcookie('bing_access_token', $access_token, $rsp->expires_in);

            return $access_token;
        }


        public function translate($word, $from, $to)
        {
            $access_token = $this->get_access_token();
            $url = 'http://api.microsofttranslator.com/V2/Http.svc/Translate?text='.$word.'&from='.$from.'&to='.$to;

            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_HTTPHEADER, array('Authorization:bearer '.$access_token));
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
            $rsp = curl_exec($ch);

            preg_match_all('/<string (.*?)>(.*?)</string>/s', $rsp, $matches);
            return $matches[2][0];
        }
    }


    //usage example
    $bt = new BingTranslation($your_client_id, $your_secret);
    echo $bt->translate('home', 'en', 'ru');
?>

GET /V2/Http.svc/Translate?text=привет мир&from=ru&to=en HTTP/1.1

$url = 'http://api.microsofttranslator.com/V2/Http.svc/Translate?text='.urlencode($word).'&from='.urlencode($from).'&to='.urlencode($to);

$url = 'http://api.microsofttranslator.com/V2/Http.svc/Translate?'.http_build_query([
            'text' => $word,
            'from' => $from,
            'to' => $to,
        ]);