bookinventory/app/Http/Controllers/MainController.php

<?php

namespace App\Http\Controllers;

use App\Models\Author;
use App\Models\Book;
use App\Models\Location;
use Illuminate\Http\Request;
use Illuminate\Support\Arr;

class MainController extends Controller {
    public function index() {
        $rows = Book::paginate(15);

        return view('index', [ 'rows' => $rows ]);
    }

    public function search(Request $request) {
        $this->validate($request, [
            'query' => [ 'required' ]
        ]);

        $rows = Book::where('name', 'LIKE', '%' . $request->get('query') . '%')->paginate(15);

        return view('index', [ 'rows' => $rows ]);
    }

    public function add(Request  $request) {
        return view('add', [
            'old' => array_filter($request->old('books', []), function($item) {
                return !empty($item['barcode']);
            })
        ]);
    }

    public function save(Request $request) {
        $this->validate($request, [
            'location' => [ 'required' ]
        ]);

        $input = array_filter($request->get('books'), function($item) {
            return !empty($item['barcode']) && !empty($item['name']);
        });

        $this->getValidationFactory()->make($input, [
            '*.barcode' => [ 'required' ],
            '*.name' => [ 'required' ]
        ]);

        $location = Location::firstOrCreate([
            'name' => trim($request->get('location'))
        ]);

        foreach ($input as $item) {
            $book = Book::create([
                'location_id' => $location->id,
                'barcode' => $item['barcode'],
                'name' => $item['name']
            ]);

            $authors = [];

            foreach (Arr::get($item, 'authors') as $author) {
                $authors[] = Author::firstOrCreate([
                    'name' => $author
                ]);
            }

            $authors = array_map(function($author) { return $author->id; }, $authors);

            $book->authors()->attach($authors);
        }
    }
}