public function post_token()
 {
     $this->filter('before', 'oauth2');
     $oauth = new OAuth2Server\Libraries\OAuth2(new OAuth2StorageLaravel());
     try {
         $oauth->grantAccessToken();
     } catch (OAuth2Server\Libraries\OAuth2ServerException $oauthError) {
         $oauthError->sendHttpResponse();
     }
 }
/*
|--------------------------------------------------------------------------
| Route Filters
|--------------------------------------------------------------------------
*/
Route::filter('before', function () {
    // Do stuff before every request to your application...
});
Route::filter('after', function ($response) {
    // Do stuff after every request to your application...
});
Route::filter('csrf', function () {
    if (Request::forged()) {
        return Response::error('500');
    }
});
Route::filter('auth', function () {
    if (Auth::guest()) {
        return Redirect::to('login')->with('backlink', URL::full());
    }
});
Route::filter('oauth2', function () {
    try {
        $oauth = new OAuth2Server\Libraries\OAuth2(new OAuth2StorageLaravel());
        $token = $oauth->getBearerToken();
        $verify = $oauth->verifyAccessToken($token);
        Auth::login($verify['user_id']);
    } catch (OAuth2Server\Libraries\OAuth2ServerException $oauthError) {
        $oauthError->sendHttpResponse();
    }
});