laravel_demo/app/Http/Controllers/AuthorController.php

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Models\Author;

class AuthorController extends Controller {
	function index() {
		$authors = Author::all();

		return view("authors", ["rows" => $authors]);
	}

	function add() {
		return view("add_author_form");
	}

	function view(Author $author) {
		return view("author", ["author" => $author]);
	}

	function edit(Author $author) {
		return view("edit_author_form", ["author" => $author]);
	}

	function store(Request $request) {
		$request->validate([
			"id" => "nullable|exists:authors",
			"name" => "required",
			"description" => "nullable"
		], [
			"name" => "Автор должен иметь имя."
		]);

		$arr = $request;

		$author = Author::find($arr->id) ?? new Author;
		$author->name = $arr->name;
		$author->description = $arr->description;
		$author->save();

		return view("success");
	}
}