Serializing nested object private fields - php

Question

I've got one Aggregate root - Product - that has few fields and some of them are objects, like Price. It looks like that ( of course it is simplified ):
Product
{
private $price;
public function __construct(Price $price)
{
$this->price = $price;
}
}
Price
{
private $currency;
private $amount;
public function __construct($currency, $amount)
{
$this->currency = $currency;
$this->amount= $amount;
}
}
This aggregate root doesn't contain "getPrice" method, it's not needed in Domain.
The issue:
I need to serialize this aggregate, but I would like to have it in this format:
Product.json
{
"priceCurrency": "GBP",
"priceAmount": 100
}
I've been trying with JMSSerializer, but can't really get it from config. This for example doesn't work:
Product.yml
Namespace\Product:
virtual_properties:
getAmount:
exp: object.price.amount
serialized_name: priceAmount
type: integer
getCurrency:
exp: object.price.currency
serialized_name: priceCurrency
type: string
I understand that it's due to the fact, that "exp" part is being used by Symfony Expression Language and from what I know it doesn't support getting values from private fields in any other way then through theirs methods. I also know that JMSSerializer itself supports that. I don't have to have field "getPrice" to serialize "price" field.
Question: Is there any way to achieve what I want just through config or do I have to write listeners on post_serialize event?

Answer 1

Use something like this:
<?php
class Property
{
protected $reflection;
protected $obj;
public function __construct($obj)
{
$this->obj = $obj;
$this->reflection = new ReflectionObject($obj);
}
public function set($name, $value)
{
$this->getProperty($name)->setValue($this->obj, $value);
}
public function get($name)
{
return $this->getProperty($name)->getValue($this->obj);
}
protected function getProperty($name)
{
$property = $this->reflection->getProperty($name);
$property->setAccessible(true);
return $property;
}
}
// example
class Foo
{
protected $bar = 123;
public function getBar()
{
return $this->bar;
}
}
$foo = new Foo();
echo 'original: '.$foo->getBar().PHP_EOL;
$prop = new Property($foo);
echo 'reflection - before changes: '.$prop->get('bar').PHP_EOL;
$prop->set('bar', 'abc');
echo 'after changes: '.$foo->getBar().PHP_EOL;