PHP catching excepion from another class in a loop - php

Question

I'm total PHP newbie, learning while creating following app. I got stuck trying to catch exception which breaks the loop in class Basic. Exception comes from class ProductVariation. Function generateRandomItems should generate random items on base of class Product and product.json file and skip productVariation when color is null.
<?php
class Product implements Item
{
public $id;
public $name;
public $price;
public $quantity;
public function __construct($file)
{
if (!file_exists($file)) {
throw new Exception('ProductFileNotFound');
}
$data = file_get_contents($file);
$product = json_decode($data);
$id = $product->id;
$name = $product->name;
$price = $product->price;
$quantity = $product->quantity;
$this->id = $id;
$this->name = $name;
$this->price = $price;
$this->quantity = $quantity;
}
public function getAmount()
{
$this->amount = $this->price * $this->quantity;
return $this->amount;
}
public function __toString()
{
$output = '';
foreach ($this as $key => $val) {
$output .= $key . ': ' . $val . "<br>";
}
return $output;
}
public function getId()
{
return $this->id;
}
public function getNet($vat = 0.23)
{
return round($this->price / (1 + $vat), 2);
}
}
class ProductVariation extends Product
{
public $color;
public function __construct($file, $color)
{
parent::__construct($file);
$this->color = $color;
if (!is_string($color)) {
throw new Exception('UndefinedVariantColor');
}
return $this->color;
}
}
interface Item
{
public function getId();
public function getNet($vat);
}
class Products extends ArrayIterator
{
public function __construct($file, $color)
{
$this->product = new Product($file);
$this->productVariation = new ProductVariation($file, $color);
}
}
class Basic
{
public function generateRandomString($randomLength)
{
$characters = 'abcdefghijklmnopqrstuvwxyz';
$charactersLength = strlen($characters);
$randomString = '';
for ($i = 0; $i < $randomLength; $i++) {
$randomString .= $characters[rand(0, $charactersLength - 1)];
}
return $randomString;
}
public function generateRandomItems($length)
{
$colors = array(
"red", "green", "blue",
"white", "black", null,
);
$list = [];
for ($i = 2; $i < $length + 2; $i += 2) {
$color = $colors[array_rand($colors, 1)];
$products = new Products('product.json', $color);
$products->product->id = $i - 1;
$products->product->name = $this->generateRandomString(rand(3, 15));
$products->product->price = rand(99, 10000) / 100;
$products->product->quantity = rand(0, 99);
$products->productVariation->id = $i;
$products->productVariation->name = $this->generateRandomString(rand(3, 15));
$products->productVariation->price = rand(99, 10000) / 100;
$products->productVariation->quantity = rand(0, 99);
echo $products->product;
echo $products->productVariation;
array_push($list, $products->product, $products->productVariation);
}
$uid = uniqid();
$fp = fopen("products/" . $uid . '.json', 'w');
fwrite($fp, json_encode($list));
fclose($fp);
}
}
product.json file content is {"id":1,"name":"Produkt testowy","price":13.99,"quantity":19}

Answer 1

For one, the check should precede the assignment to check if it’s null (this is in your Basic class).
// put check first
if (!is_string($color)) {
throw new Exception('UndefinedVariantColor');
}
$this->color = $color;