Do you supports default property value for readonly properties?

[roquie]

Example:

class Acme {
  public function __construct(
      #[DefaultValue('bar')]
      private readonly string $foo,
      private readonly string $baz,
  ) {}
}

Let's map it:

map(Acme::class, [
    'baz' => 'test'
]);

Expected result:

[
  'foo' => 'bar',
  'baz' => 'test'
]

m?

[romm]

Default value is an existing PHP feature, if you want to take advantage of it just use it as below, the mapper will handle it properly.

class Acme {
  public function __construct(
      private readonly string $baz,
      private readonly string $foo = 'bar',
  ) {}
}

[roquie]

Your example will be successful for non read only properties. Attempting to hydration read only property with field who has default value will throw an PHP error (should be declared once).

My question is about opportunity to have filled read only property after hydration if it presented or to set default value it from attribute.

[romm]

Ok I see the issue here, you're talking about properties that are not promoted.

Indeed the following code fails hard:

class Acme {
    private readonly string $foo = 'bar';
    private readonly string $baz;
}

I'll think about a solution, but you're probably right: an attribute looks like the best way to do it.

[roquie]

Thanks! I hope to see this feature :)

Attributes also can help convert source value to typed property (interface or object).

For example:

class Acme {
  public function __construct(
      #[FieldMapper\RamseyUuid] 
      private readonly UuidInterface $foo,
      private readonly string $baz,
  ) {}
}
// ...
map(Acme::class, [
     'foo' => '58054f1d-fbfc-4349-9c4a-4d7f22b63369',
    'baz' => 'test'
]);

It real use case from my application.

[romm]

Attributes also can help convert source value to typed property (interface or object).

This is actually an existing feature, not documented yet because there are chances the API will soon change.

You can use the following:

(new \CuyZ\Valinor\MapperBuilder())
    ->infer(UuidInterface::class, fn () => RamseyUuid::class)
    ->map(SomeClass::class, [/* … */];

But once again, be aware that this API may change soon.