Array of services injection

[jakubkulhan]

When array is "type hinted", autowiring looks if type is specified in doc comment and wires array of all matching services.

E.g.

interface SlugRepositoryInterface {
    function getBySlug($slug);
}

class FooRepository implements SlugRepositoryInterface {
    public function getBySlug($slug) { ... }
}

class BarRepository implements SlugRepositoryInterface {
    public function getBySlug($slug) { ... }
}

class SlugTrailService {

    /** @var SlugRepositoryInterface[] */
    private $repositories;

    /**
     * @param SlugRepositoryInterface[]
     */
    public function __construct(array $repositories) {
        $this->repositories = $repositories;
    }

    public function findAllBySlug($slug)
    {
        return array_map(function (SlugRepositoryInterface $r) use ($slug) { return $r->getBySlug($slug); }, $this->repositories);
    }
}

[kutny]

Hi, thank you for this idea. What happens if I need services in that array in some specific order? How can I do it? Only by wiring them manually? What if I do not need to pass all services that implement SlugRepositoryInterface to SlugTrailService?

I'm not sure, but this approach seems too magical to me.

[jakubkulhan]

The idea came from Spring Framework, where IoC container can autowire List<T> arguments. In use cases I have encountered in Java, order wasn't either important, or order was clearly defined by return of one of their methods, so sorting passed in list solved it.

About the latter question, the interface servers here as a marker - I can't think of any case where I would make service implement such interface and then wouldn't want to have it injected :)