Mapping Inheritance

Inheritance of base class configuration is not automatic, it requires explicit opt-in. You can specify the mapping to inherit from the base type configuration using the include() method, or within the derived type configuration using the includeBase() method.

info

When usiing include() or includeBase(), only the member configuration is inherited.

tip

If you do not have any custom member configuration in the base type, inheritance is optional since matching member names will still be mapped automatically.

Using include()

The include() method is used to include the mappings from one specific map into another. This is useful when you have two classes that have similar properties and you want to avoid duplicating the mapping configuration.

Here is an example:

$config = new MapperConfiguration(fn (Config $config) => $config
    ->createMap(BaseClass::class, BaseDto::class)
        ->forMember('property1', fn (Options $opts) => $opts->mapFrom(fn (BaseClass $source) => $source->property1))
        ->include(DerivedClass::class, DerivedDto::class)
    ->createMap(DerivedClass::class, DerivedDto::class)
);

In this example, DerivedClass is a derived class of BaseClass, and DerivedDto is a derived class of BaseDto. The include() method is used to include the mappings from BaseClass to BaseDto into the map from DerivedClass to DerivedDto.

Using includeBase()

The includeBase() method is used to include the mappings from a base map into the current map. This is useful when you have a base class and multiple derived classes, and you want to include the mappings of the base class into all the derived classes.

Here is an example:

$config = new MapperConfiguration(fn (Config $config) => $config
    ->createMap(BaseClass::class, BaseDto::class)
        ->forMember('property1', fn (Options $opts) => $opts->mapFrom(fn (BaseClass $source) => $source->property1))
    ->createMap(DerivedClass1::class, DerivedDto1::class)
        ->includeBase(BaseClass::class, BaseDto::class)
    ->createMap(DerivedClass2::class, DerivedDto2::class)
        ->includeBase(BaseClass::class, BaseDto::class)
);

In this example, DerivedClass1 and DerivedClass2 are derived classes of BaseClass, and DerivedDto1 and DerivedDto2 are derived classes of BaseDto. The includeBase() method is used to include the mappings from BaseClass to BaseDto into the maps from DerivedClass1 to DerivedDto1 and from DerivedClass2 to DerivedDto2.

Alias

You can also use the as() method to specify an alias for the included map. This can be useful when you want to use the same map configuration for multiple types.

Here is an example:

$config = new MapperConfiguration(fn (Config $config) => $config
    ->createMap('array', ArrayCollection::class)
    ->createMap('array', Collection::class)
        ->as(ArrayCollection::class)

You can use the as() method to specify that the map configuration from ArrayCollection should be used for Collection.

tip

This is especially useful because for interfaces. You do not need a TypeFactory for the Collection type, since it will use the ArrayCollection instantiation.