[ObjectMapper] Add support for nested source

[TakTaki]

Description

Hi,

I'm trying to work with the #[Map(source: XXX)] and it seems to me that nested object with source mapped is not working properly.

I'm not really sure if that is something that should work or not ?
Thank you !

Example

Here is a simple example :

final readonly class A {
    public function __construct(
        public B $b,
        public string $var1,
    ) {}
}

final readonly class B {
    public function __construct(
        public string $var2,
    ) {}
}

#[Map(source: A::class)]
final readonly class AMapped {
    public function __construct(
        #[Map(transform: BMapped::class)]
        public BMapped $b,
        #[Map(source: 'var1')]
        public string $var1Mapped,
    ) {}
}

#[Map(source: B::class)]
final readonly class BMapped {
    public function __construct(
        #[Map(source: 'var2')]
        public string $var2Mapped,
    ) {}
}

/** @var AMapped $out */
$out = (new ObjectMapper())->map(
    source: new A(
        b: new B(
            var2: 'bar',
        ),
        var1: 'foo',
    ),
    target: AMapped::class,
);
var_dump($out);
echo $out->b->var2Mapped;

This output :

TypeError: AMapped::__construct(): Argument #1 ($b) must be of type BMapped, B given, called in /var/www/html/vendor/symfony/object-mapper/ObjectMapper.php on line 167

[fperxas]

Hi, is it possible that you are trying to transform B object to BMapped object through the #[Map(transform: BMapped::class)] attribute?

I don't think it is meant to be used that way, reading the docs Transforming Values it states that you can use the transform option:

Use the transform option within #[Map] to change a value before it is assigned to the target. 

And that this options should be:

This can be a callable (e.g., a built-in PHP function, static method, or anonymous function) or a service implementing TransformCallableInterface

If you are trying to turn the B object to a BMapped object using transform, I think that you can create a new property on A (i.e. BMappedProp) and use a callable of some kind to convert the B object to BMapped and assign it to the BMappedAttr for future use.

[soyuka]

is this related to #62357 ?

[fperxas]

well, indeed it seems that the example provided is nearly the same as the one in this PR comment: #62377 (comment)

although in that comment they don't seem to use the attribute Map option transform for the public B $b property

#[Map(target: AMapped::class)]
final readonly class A {
    public function __construct(
        public B $b,
        public string $var1,
    ) {}
}

Maybe this issue can be closed in favor of #62357 ?

[TakTaki]

is this related to #62357 ?

I looked a this issue and copied the example. The main difference is that I want to use the #[Map(source: XXX)] instead of the #[Map(target: XXX)].

[TakTaki]

Hi, is it possible that you are trying to transform B object to BMapped object through the #[Map(transform: BMapped::class)] attribute?

I don't think it is meant to be used that way, reading the docs Transforming Values it states that you can use the transform option:

Use the transform option within #[Map] to change a value before it is assigned to the target. 

And that this options should be:

This can be a callable (e.g., a built-in PHP function, static method, or anonymous function) or a service implementing TransformCallableInterface

If you are trying to turn the B object to a BMapped object using transform, I think that you can create a new property on A (i.e. BMappedProp) and use a callable of some kind to convert the B object to BMapped and assign it to the BMappedAttr for future use.

The thing is that I want to keep the same naming, so the class B b property of class A must transformed to the class BMapped b property of class AMapped

[fperxas]

I don't think that you can use transform to change the type from B to BMapped (if it is possible I have missed it from the docs), you can change the value, you can change the value for an existing property but it will have its own type.

I have built you an example. It is not what you want but maybe you can extract some ideas from it.

final readonly class A {
    public BMapped $bmapped;

    public function __construct(
        public B $b,
        public string $var1,
    ) {
        $this->bmapped = new ObjectMapper()->map($b, BMapped::class);
    }
}

final readonly class B {
    public function __construct(
        public string $var2,
    ) {}
}

final readonly class AMapped {
    public function __construct(
        #[Map(source: 'var1')]
        public string $var1Mapped,
        #[Map(source: 'bmapped')]
        public BMapped $c,
    ) {}
}

final readonly class BMapped {
    public function __construct(
        #[Map(source: 'var2')]
        public string $var2Mapped,
    ) {}
}

$out = (new ObjectMapper())->map(
    source: new A(
        b: new B(
            var2: 'bar',
        ),
        var1: 'foo',
    ),
    target: AMapped::class,
);
var_dump($out);
echo $out->c->var2Mapped;

You can also build your own custom mapping logic.

[soyuka]

@fperxas interesting, at some point maybe we should add an interface that would inject the mapper in transforms (ObjectMapperAwareInterface) so that you get the correct service.

@TakTaki Mhh maybe that #62522 actually fixes your issue