partial_deserialisation.php

<?php

use JMS\Serializer\Annotation as JMS;
use JMS\Serializer\SerializerBuilder;

class A {
    /**
     * @JMS\Type("integer")
     */
    protected $x;
  
    /**
     * @JMS\Type("integer")
     */
    protected $y;
  
    public function __construct($x, $y) {
        $this->x = $x;
        $this->y = $y;
    }
}

class B {
    /**
     * @JMS\Type("integer")
     */
    protected $x;
  
    public function __construct($x) {
        $this->x = $x;
    }
}

$serializer = SerializerBuilder::create()->build();
$a = new A(123, 456);
$a_json = $serializer->serialize($a, 'json');
$b = $serializer->deserialize($a_json, B::class, 'json');

/*
>>> var_dump($a)
object(A)#359 (2) {
  ["x":protected]=>
  int(123)
  ["y":protected]=>
  int(456)
}
=> null
>>> var_dump($a_json)
string(17) "{"x":123,"y":456}"
=> null
>>> var_dump($b)
object(B)#296 (1) {
  ["x":protected]=>
  int(123)
}
*/