Hi,
Am 15.10.22 um 13:18 schrieb Gianni Gentile:
Hi,
in my every day experience, using custom DTO classes and different API,
I often write code to instantiate my objects from associative arrays.
What are your thoughts on introduce the `(AnyType)` cast to instantiate
objects from associative array (or object properties also)?
In my proposal, if AnyType implements __set_state(), casting should be
syntactic sugar for:
AnyType::_set_state((array) $data)
just for (useless) example, consider DateTime or DateTimeImmutable (both
have __set_state() implementation); when applied to objects of that
type, we can write:
$dt = new DateTime();
$dtArray = (array) $dt; // 3 elements array
$copyOfDt = (DateTime) $dtArray; // or simply $copyOfDt =
(DateTime) $dt;
In case AnyType does not implements __set_state(), casting should create
a new instance, assigning values to properties, taken from array values
with corresponding key (in a similar way class objects are created when
row is fetched from database specifying PDO_FETCH_CLASS) eventually
invoking __set() magic method for properties not declared;
In this scenario,
(object) ['one' => 1, 'two' => 2]
and
(StdClass) ['one' => 1, 'two' => 2]
do exactly the same work.
Reasons:
- clear code
- array to object conversion (casting) would be the simmetrical
counterpart of object to array conversion
I see your use case and I often have similar needs. Some thoughts:
* Are there any restrictions regarding the matching of array keys and
the class attributes? What if there are additional keys in the array
that do not have corresponding attributes? What if there are some
attributes in the class that do not exist in the array?
* Can I forbid a class to be created by casting from an array? When I
think about domain entities/aggregates, such a casting would allow to
create an invalid state of the object without any checks. (Okay, we have
similar issues when recreating them from a database via some ORM.)
BTW:
<?php declare(strict_types=1);
class A
{
private string $myPrivate = 'private';
protected string $myProtected = 'protected';
public string $myPublic = 'public';
}
$a = new A();
var_dump((array) $a);
?>
Will dump with modified array keys:
/home/thomas/test.php:12:
array(3) {
'\0A\0myPrivate' =>
string(7) "private"
'\0*\0myProtected' =>
string(9) "protected"
'myPublic' =>
string(6) "public"
}
So it's not as symmetric as intended.
Regards
Thomas
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