Unable to start class in php

Question

I'm doing a PHP form with ajax but having trouble initializing a class ou classes. I think the problem is with the path, I have a addproduct.php with this form, i don't believe posting the form will help beacause it isnt getting any error, but if you think it is, let me know so i can post it.

Infrastructure of the project

This is where i submit the form (posproduct.js)

$(document).on('submit', '#product_form', function(){
    
    var $form = $('#product_form');
    var dados = $form.serialize();
    
    $.ajax({
        type: 'POST',
        url: 'form.php',
        async: true,
        dataType: "html",
        data: dados
    }).done(function(msg){
         window.location.href = "index.php";
    }).fail(function(jqXHR, textStatus, msg){
         alert(dados);
         console.log(jqXHR, textStatus, msg);
    });
    return false;
});

Here i enter in this try catch but dont get this error, only if i take out the "//" (form.php)

<?php 
    //require_once("config.php");
    include_once('/class/Book.php');
    include_once('/class/DVD.php');
    include_once('/class/Forniture.php');

    saveProduct();
    function saveProduct(){
        $ok = 0;

        try {
            //http_response_code(405);
            $book = new Book();
            http_response_code(405);
            $book->setDescription($size);
            $book->setSku($sku);
            $book->setName($name);
            $book->setPrice($price);
            $book->setType($type);
            $book->insert();

            http_response_code(401);
            //$ok += 1;

        } catch (Exception $e) {
            //echo "$e";
        }

My Book Class

<?php
include_once('/class/Product.php');

class Book extends Product
{
    public function setDescription(int $value)
    {
        $this->description = $value;
    }
}
 ?>

My product class

<?php 
include_once('DAO.php');
abstract class Product
{
    protected $sku;
    protected $name;
    protected $price;
    protected $type;
    protected $description;

    public function getSku()
    {
        return $this->sku;
    }

    public function setSku($value)
    {
        $this->sku = $value;
    }
    public function getName(){
        return $this->name;
    }

    public function setName($value)
    {
        $this->name = $value;
    }

    public function getPrice()
    {
        return $this->price;
    }

    public function setPrice($value)
    {
        $this->price = $value;
    }

    public function getType()
    {
        return $this->type;
    }

    public function setType($value)
    {
        $this->type = $value;
    }

    public function getDescription()
    {
        return $this->description;
    }

    abstract public function setDescription($value);

    public function insert()
    {
        $dao = new Dao();
        $result = $dao->query("INSERT INTO tb_produtos (sku, pname, price, ptype, pdescription) VALUES(:SKU, :NAME, :PRICE, :TYPE, :DESCRIPTION)", array(
            ":SKU"=> $this->getSku(),
            ":NAME"=> $this->getPname(),
            ":PRICE"=> $this->getPrice(),
            ":TYPE"=> $this->getType(),
            ":DESCRIPTION"=> $this->getDescription()
        ));
    }

    public function getList()
    {
        $dao = new Dao();

        return $dao->select("SELECT * FROM tb_produtos ORDER BY id;");
    }

    public function __toString()
    {
        return json_encode(array(
            "sku"=>$this->getSku(),
            "name"=>$this->getName(),
            "price"=>$this->getPrice(),
            "type"=>$this->getType(),
            "description"=>$this->getDescription()
        ));
    }
}

?>

Answer 1

The problem was that is missing a "int" into abstract public function setDescription($value);