smart table export service

ExampleController.php

<?php

class UserController extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @param Request $request
     * @return Response|JsonResponse
     * @throws AuthorizationException
     */
    public function index(Request $request): Response|JsonResponse|StreamedResponse
    {

        $this
            ...
            ->option('export', 'nullable|in:true')
            ->option('cols', 'nullable')
            ->verify();

        $this->authorize('viewAny', auth()->user());
        $query = User
            ::when(
                $request->search,
                fn($q) => $q->where('name', 'LIKE', "%$request->search%")
            )
            ...
            );

        if ($request->export === 'true' && $request->cols) {
            return response()->stream(
                SmartTable::callback($request->cols, $query),
                200,
                SmartTable::headers('users')
            );
        }

        return $this->render($this->paginate($query, $request->perpage ?? 10));
    }

SmartTable.php

<?php

namespace App\Services;

use Closure;
use Illuminate\Database\Eloquent\Builder;

class SmartTable
{
    public static function callback(string $cols, Builder $query): Closure
    {
        return function () use ($cols, $query) {
            $labels = array_map(fn($c) => substr($c, strpos($c, ':') + 1), explode(',', $cols));
            $fields = array_map(fn($c) => strtok($c, ':'), explode(',', $cols));
            $file = fopen('php://output', 'w');
            fputcsv($file, $labels);
            foreach ($query->get($fields) as $row) {
                fputcsv($file, $row->only($fields));
            }
            fclose($file);
        };
    }

    public static function headers(string $name): array
    {
        $file = $name . '-' . date(DATE_W3C);
        return [
            'Content-Type' => 'text/csv',
            'Content-Disposition' => "attachment; filename=$file.csv",
            'Pragma' => 'no-cache',
            'Cache-Control' => 'must-revalidate, post-check=0, pre-check=0',
            'Expires' => '0',
        ];
    }
}