any update/feedback/opinions on this PR? 🙃

Friendly ping@aschempp

Sorry I didn't have time yet to update this. I'll give it a try in the coming weeks.

I've updated the PR, added some text and fixed major bugs 🙈
The failing PHP8 tests seem unrelated to me.

Friendly ping@nicolas-grekas 😅

How do the dumpers behave with array as tag attributes? Can you please add some tests for that?

I'm sorry I might not be familiar with that concept. What "Dumpers" are you referring to?

First of all, thank you for working on this feature. It's something that I really struggle with myself and I hope this will be possible one day 🙏

To answer your question,@nicolas-grekas talks about dumpers likeSymfony\Component\DependencyInjection\Dumper\XmlDumper. They are used to dump the compiled container to thevar/cache directory. (If you would try this on a real application/project you would see an error too)

As far as I can see your PR only makes it possible to have array tags in configurations (read side). But the PR should also fix the write side.

To solve that, add a test case toSymfony\Component\DependencyInjection\Tests\Dumper\XmlDumperTest:

publicfunctiontestNonScalarTags()    {$container =includeself::$fixturesPath.'/containers/container_non_scalar_tags.php';$dumper =newXmlDumper($container);$this->assertEquals(file_get_contents(self::$fixturesPath.'/xml/services_with_array_tags.xml'),$dumper->dump());    }

and create a fixture like this:

<?phprequire_once__DIR__.'/../includes/classes.php';require_once__DIR__.'/../includes/foo.php';useBar\FooClass;useSymfony\Component\DependencyInjection\ContainerBuilder;$container =newContainerBuilder();$container    ->register('foo', FooClass::class)    ->addTag('foo_tag', ['foo' =>'bar','bar' => ['foo' =>'bar','baz' =>'foo'        ]]);return$container;

When you run it, you'll see that the Dumper breaks:

1) Symfony\Component\DependencyInjection\Tests\Dumper\XmlDumperTest::testNonScalarTagsTypeError: DOMElement::setAttribute(): Argument #2 ($value) must be of type string, array given/Users/Ruud/opensource/symfony/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php:147/Users/Ruud/opensource/symfony/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php:272

That foreach should be altered to support arrays and write the XML in the new format.

Hope it helps 😊

@aschempp up to finish this PR?

I'm closing here because this staled and also because on second though I'm not sure it will work smoothly. Also because re-reading the original issue, turning tags into annotations doesn't feel like a good idea to me, at least not without using the autoconfiguration mechanism.registerAttributeForAutoconfiguration() provides a way to do that natively. This provides a hook that would allow serializing complex structures found in the attribute into eg json, so that the description can fit a tag.

Closing as such, thanks for proposing!

Sorry for being stale, I was just about to update that (started yesterday after finishing#42355). I just updated the PR but it seems GH does not update here if the PR is closed.

Not exactly sure what you mean byturning tags into annotations. The change simply allows for recursive tag attributes. A compiler pass can then use this information to do whatever they want.
In our case, we have tags to define a service as a controller, and the route configuration has a name, path and an array of requirements etc., hence the requirement for an array of tag attributes.

I meant turning annotations into tags sorry (withthis).
How do you do right now? Wouldn't my suggestion above work for you?

I meant turning annotations into tags sorry (withthis).

Yeah that's basically a predecessor of the PHP8 attributes we've had for a few years now 😎 (although it is obviously deprecated now that we have attributes)

How do you do right now? Wouldn't my suggestion above work for you?

If I remember correctly, both using our annotations as well as our newly added attributes works fine. Even though attributes/annotations are converted to tags, there is no validation on them not being arrays. It just does not work when trying to define the same in YAML or XML.

Even though attributes/annotations are converted to tags, there is no validation on them not being arrays. It just does not work when trying to define the same in YAML or XML.

Oh, and how does the XML dump look like?

I can't reopen but please resubmit if you want.

XML will look like this 😊
https://github.com/symfony/symfony/pull/38540/files#diff-16371727bd7f17a541f80dec3603214facfb14f0848930e8567c54c0a06eae8b

see#47364 for the reopened PR