Calling callables

Besides building objects, the container can invoke a callable and autowire the arguments it does not receive explicitly. This is what a router or CLI framework uses to call a controller action or command handler: it passes the arguments it knows (route parameters, the request) and lets the container supply the rest from its bindings.

The call method

call accepts three shapes of callable:

• a Closure,
• an array [object|class-string, method],
• an invokable class string (a class with an __invoke method).

Each parameter of the callable is resolved the same way a constructor parameter is, using the autowiring rules from Autowiring and attributes.

<?php
declare(strict_types=1);

use Raxos\Container\Container;

$container = new Container();

$result = $container->call(static fn(Database $database): int =>
    $database->count('users'));

Overriding arguments

Named arguments passed in $args take precedence over autowired values. They are matched by parameter name, so any parameter present in the array is taken from it and the rest are autowired:

$container->call([$reportController, 'show'], [
    'id' => 42,
]);

Here id comes from the array, while a Database or Request parameter on show is resolved from the container.

Invokable classes

A class string that implements __invoke is instantiated (and autowired) before being called:

<?php
declare(strict_types=1);

final readonly class SendWelcomeMail
{
    public function __construct(
        public MailerInterface $mailer,
    ) {}

    public function __invoke(User $user): void
    {
        $this->mailer->send(/* ... */);
    }
}

$container->call(SendWelcomeMail::class, [
    'user' => $user,
]);

When the given value is not a closure, a valid [target, method] pair, or an invokable class string, call throws an InvalidCallableException.