sarga/packages/Webkul/Shop/src/Http/Middleware/Locale.php

<?php

namespace Webkul\Shop\Http\Middleware;

use Webkul\Core\Repositories\LocaleRepository;
use Closure;

class Locale
{
    /**
     * @var LocaleRepository
     */
    protected $locale;

    /**
     * @param \Webkul\Core\Repositories\LocaleRepository $locale
     */
    public function __construct(LocaleRepository $locale)
    {
        $this->locale = $locale;
    }

    /**
    * Handle an incoming request.
    *
    * @param  \Illuminate\Http\Request  $request
    * @param  \Closure  $next
    * @return mixed
    */
    public function handle($request, Closure $next)
    {
        if($locale = $request->get('locale')) {
            if($this->locale->findOneByField('code', $locale)) {
                app()->setLocale($locale);

                session()->put('locale', $locale);
            }
        } else {
            if($locale = session()->get('locale')) {
                app()->setLocale($locale);
            }
        }

        return $next($request);
    }
}