Caching class for production

Instead of caching metadata of a class, AutoMapper generates a class in PHP that remove all reflection calls and the overhead of the decision process. This class is generated in the cache directory of your Symfony application.

In order to do that it needs to know which mapping you want to generate. By default, it will generate the mapper when asked for the first time.

This may not be suited in a production environment, as it may slow down the first request or the disk may not be writable resulting in an error.

To avoid this problem, you can specify the mappings you want to generate in the configuration file :

automapper:
  mappings:
    mappers:
      - source: App\Entity\User
        target: App\Api\DTO\User

      - source: App\Entity\User
        target: array
        reverse: true

Then when running the cache:warmup command, this will generate the mappers for you.

Note

When a mapping have dependencies, it will generate the dependencies as well even if not specified in the mappings configuration.

This way, you can generate all the mappers you need before deploying your application.

Automatically register mappers

You can also define a list of paths where the mappers are located, and the bundle will automatically register them for you.

automapper:
  mappings:
    paths:
      - "%kernel.project_dir%/src/Entity"

All classes in the specified paths with the #[Mapper] attribute will be registered in the container.

This attribute need a source and/or target argument to specify which mapping to register.

#[Mapper(source: 'array', target: 'array')]
class Entity
{
    public string $foo;
}

This will generate a mapper from array to Entity and vice versa during the cache warmup.

You can also specify an array of sources and / or targets to generate multiple mappers at once.

#[Mapper(source: 'array', target: ['array', EntityDto::class])]
class Entity
{
    public string $foo;
}