Might be a weird brainfart, but what about allowing a map of <number>: <argument> under autowire additionally to true? This would leave the arguments as is without modifications but allows any edge-cases configurable under the autowire key.

@iltar So first, there is still a bug here - I want to make sure we keep that focus :).

But, your idea is interesting. Well actually, if it weren't for this bug, you can already do what you're saying, just under the arguments keys using indexes 0, 1, 2, etc. However, it might be interesting with autowiring to allow named arguments - as it's a bit weird to specify your "argument index 1" value. So then:

services:
    product_repository:
        class: AppBundle\Repository\ProductRepository
        autowire:
            logger: '@logger'

In theory, this could also still just be done under arguments (it's just a different way of specifying arguments), but autowiring is the only thing currently that uses reflection (needed to get the arg name)... so I'm not sure if it would make sense there. But maybe :)

@weaverryan this use case is already supported (https://github.com/symfony/symfony/blob/master/src/Symfony/Component/DependencyInjection/Compiler/AutowirePass.php#L75)

The following snippet should work:

services:
    product_repository:
        class: AppBundle\Repository\ProductRepository
        autowire: true
        arguments: [ '', '@logger' ]

It looks weird in YAML (but works), it's far better in XML:

<service id="product_repository" class="AppBundle\Repository\ProductRepository" autowire="true">
    <argument />
    <argument type="service" id="logger" />
</service>

@dunglas

You're right - but it's odd: if I use your same syntax but with null, it'll fail:

services:
    product_repository:
        class: AppBundle\Repository\ProductRepository
        autowire: true
        arguments:
            - ~
            - '@logger'

Anyways, with your working example, it just doesn't feel right. One day, autowiring might work great. Then suddenly I add a 4th constructor argument that can't be autowired. Suddenly I need to add 5 lines (arguments and the lines below) to make the service work again:

services:
    product_repository:
        class: AppBundle\Repository\ProductRepository
        autowire: true
        arguments:
            - ''
            - ''
            - ''
            - ''
            - '%kernel.root_dir%'

And if we change the order of the args (something autowiring should allow), it'll break.

What do you think about my previous suggestion? #17724 (comment)

@weaverryan it makes a lot of sense to enhance this feature. I personally prefer you're proposal of using:

services:
    product_repository:
        class: AppBundle\Repository\ProductRepository
        autowire: true
        arguments:
            1: '@logger'

Because it couples less the code with the configuration. With named parameters, if you rename a constructor parameter, it breaks the app. With numbers as keys, the only way to break the app is to change the order of parameters (and it's already considered a BC break).

👍 for argument indexes. That's already how we manage arguments internally by the way (replaceArgument()).

Hence my original suggestion, as it's simply mapped and you can use replaceArgument($number, $argument), it will be the least effort and the most intuitive.

Ok then with arguments by index! Actually, I thought that this would already work - I tried that originally and then opened this "bug" (see my original code block, it matches the last one from @dunglas) exactly.

So, this is "actionable" - someone just needs to make wiring work with a specific index.

Thanks!

PR at #17876