Deserializing from JSON into PHP, with casting?

Question

Suppose I have a User class with \'name\' and \'password\' properties, and a \'save\' method. When serializing an object of this class to JSON via json_encode, the method is pro

Answer 1

Below is an example of using both static (i.e. you know the class type in code) and dynamic (i.e. you only know the class type at runtime) to deserialize JSON back into a PHP object:

Code

brand = $brand;
        $this->model = $model;
        $this->year = $year;
    }

    public function toJson()
    {
        $arr = array(
            'brand' => $this->brand,
            'model' => $this->model,
            'year' => $this->year,
        );

        return json_encode($arr);
    }

    public static function fromJson($json)
    {
        $arr = json_decode($json, true);

        return new self(
            $arr['brand'],
            $arr['model'],
            $arr['year']
        );
    }
}

// original object
echo 'car1: ';
$car1 = new Car('Hyundai', 'Tucson', 2010);
var_dump($car1);

// serialize
echo 'car1class: ';
$car1class = get_class($car1); // need the class name for the dynamic case below. this would need to be bundled with the JSON to know what kind of class to recreate.
var_dump($car1class);

echo 'car1json: ';
$car1Json = $car1->toJson();
var_dump($car1Json);

// static recreation with direct invocation. can only do this if you know the class name in code.
echo 'car2: ';
$car2 = Car::fromJson($car1Json);
var_dump($car2);

// dynamic recreation with reflection. can do this when you only know the class name at runtime as a string.
echo 'car3: ';
$car3 = (new ReflectionMethod($car1class, 'fromJson'))->invoke(null, $car1Json);
var_dump($car3);

Output

car1: object(Car)#1 (3) {
  ["brand":"Car":private]=>
  string(7) "Hyundai"
  ["model":"Car":private]=>
  string(6) "Tucson"
  ["year":"Car":private]=>
  int(2010)
}
car1class: string(3) "Car"
car1json: string(48) "{"brand":"Hyundai","model":"Tucson","year":2010}"
car2: object(Car)#2 (3) {
  ["brand":"Car":private]=>
  string(7) "Hyundai"
  ["model":"Car":private]=>
  string(6) "Tucson"
  ["year":"Car":private]=>
  int(2010)
}
car3: object(Car)#4 (3) {
  ["brand":"Car":private]=>
  string(7) "Hyundai"
  ["model":"Car":private]=>
  string(6) "Tucson"
  ["year":"Car":private]=>
  int(2010)
}