如何将变量传递给Laravel 5.3中的内部函数？

I am trying to pass the locale data to the eloquent query but it cannot get it. $locale value is taken from the URI.

class MyController extends Controller
{

    public function index($locale = 'en')
    {
        $news = News::join('categories', 'categories.id', '=', 'news.catid')
            ->select('news.*', 'categories.category')
            ->where([['news.published', '1'], ['news.deleted', '0']])
            ->where(function ($query) {
                $query->where('news.language', $locale) //$locale is not recognized naturally
                      ->orWhere('news.language', 'all');
            })
            ->orderBy('news.published_at', 'desc')
            ->take(4)
            ->get();

             .
             .
             .
    }
}

How can I pass $locale value into the subquery?

There is the use construct that you can use to create a closure around the variable:

->where(function ($query) use($locale) {
    $query->where('news.language', $locale) 
          ->orWhere('news.language', 'all');
})

See Example #3 in the manual, "Inheriting variables from the parent scope".