[Backward campability] Error on mapping after bumping version

[gabplch]

HI! I've bumped to version 1.13 from 1.8. and started receiving some errors: When trying to map on no setters exists. This situation is possible for cases when id is generated with doctrine id generator, so setter is unnecessary here

...
class Foo
{
    #[ODM\Id(type: UuidType::NAME, options: ['class' => UuidGenerator::class], strategy: 'CUSTOM')]
    private UuidInterface $id;

   public function getId(): UuidInterface
   {...}
}

In this case mapper error is:

Rekalogika\Mapper\Transformer\Exception\NewInstanceReturnedButCannotBeSetOnTargetException: Transformation of property
"id" on object type "App\Foo" results in a different object instance from the original instance, but the new instance cannot be set
on the target object. You may wish to add a setter method to the target class. Mapping path: "(root)".

Expected behavior - the property will be ignored, and setter won't be called

How about to add smth like #[Skip] attribute, that will allow ignore property in mapping, or possibility create custom mapper on property, that will force not to map property

[priyadi]

Skipping the mapping is already possible with #[Map(null)] (or #[Map(false)] in the next release): https://rekalogika.dev/mapper/object/map#ignoring-a-property

Handling private properties without a setter turns out to be more complicated than I expected. I think I'll just replace the exception with a warning. If it is like your case, then it can be dismissed by adding #[Map(false)]. And those who really need a setter and forgot to add it can add the setter to dismiss the warning.

[gabplch]

Now there is no such an error, but it wants to set this value anyway, I've double checked, there is no setter for this property

My use case is:

class Source
{
    public function __construct(
        public string $id,
    ) {}
}

class Target
{
    private UuidInterface $id;

    private string $externalId;

    public function getId(): UuidInterface
    {....}

   public function getExternalId(): string
   {...}

   public function setExternalId(string $externalId): void
   {...}
}

class SourceToTargetMapper
{
    #[AsPropertyMapper(
        property: 'externalId',
        targetClass: Target::class,
    )]
    public function mapExternalId(Source $source): string
    {
        return $source->id;
    }
}

[priyadi]

What do you mean by "wants to set this value anyway"? As of 1.13.2, the exception is no longer there. Your case should work as before, but you will now get a warning in your log file. To dismiss the warning, you need to add #[Map(false)] on your $id property (on either source or target side).

Or do you get a different exception?

---

Why can't we just ignore target properties without a setter?

• We might be able to modify the target if it has an existing value, the value is an object, and the object has public properties or setters.
• If it has a public setter, the setter may be an immutable setter (or a wither). It can return a different instance of the host object. When that happens, Mapper is expected to set the new instance back to the target. If there is no setter, it can't do that.

Previously, the latter case was ignored. But it led to cases where mappings were silently not working without any clue why that was happening. So I made it throw an exception when that happens, and some heuristics to ignore if the target is an immutable object like DateTime or Uuid.

But the heuristic is not perfect, and it led to confusion when Mapper correctly detected the class as immutable, and when it failed to do so. So, it appears that the safest way forward is to log it as a warning. If it is like your case, you need to add #[Map(false)] to dismiss the warning.

[gabplch]

The problem is it still tries (and makes it) to write from source to target even if there is no setter method. I've tried to clear cache, dump autoload, etc, and the problem still was there.

After adding #[Map(false)] attribute, problem disappeared, but I'd like not to reference on mapper from Domain layer.

[priyadi]

The problem is it still tries (and makes it) to write from source to target even if there is no setter method. I've tried to clear cache, dump autoload, etc, and the problem still was there.

Not sure if I understand. With v1.13.2, if there is no setId() on the target, Mapper should give up mapping source id to target id, with a warning in the log file.

After adding #[Map(false)] attribute, problem disappeared, but I'd like not to reference on mapper from Domain layer.

You should be able to add #[Map(false)] on either side, and it will work the same. In your case, I think you will want to add it on the source side, not the target side. Will that be sufficient for you?

[priyadi]

Hi, I think you might have gotten "CannotFindTransformerException: Cannot find a matching transformer for mapping the source types "null" to the target types "Uuid". If that was the case, then it should be fixed in the latest version.

[gabplch]

Hm, thanks, I'll chack later, as we decided to bump a bit later, as there are some troubles with migration to newer version. You can close the issue, I'll text, if it'll reproduce