[RFC] Deprecate and remove support for semantic XML configuration

[lyrixx]

Description

Maintaining https://github.com/symfony/symfony/blob/7.3/src/Symfony/Bundle/FrameworkBundle/Resources/config/schema/symfony-1.0.xsd is not easy.
And I never saw a project using XML to configure the framework.

So I propose to remove this support. I know it's always heartbreaking to remove a feature, but I really think it's much better for Symfony maintainers.

More over, we now have much better format to configure the framework...

Example

No response

[lyrixx]

maybe it can be generated from the Configuration definition?

What do you mean by "it"?

deprecating format X can be really painful for (some) users, im not sure it's generally worth it, since it's just format X

I agree but I really didn't see any project using it. More over, this configuration formation is painful to use (event for end user)

And Doctrine has already removed a configuration format. So there is a precedent 😃

[GromNaN]

maybe it can be generated from the Configuration definition?

This is not trivial as there is some transformations of the input before validating the configuration (example in DoctrineBundle) that requires a specific schema file. We hit this issue while trying to generate the JSON schema configuration in #59620

And I never saw a project using XML to configure the framework.

We can decide to deprecate this format and possibly reconsider this decision before deleting it, if people contest with specific use cases.

[lyrixx]

maybe do some public polls first?

I'd like to, but I don't know where we could put it to reach the maximum number of people.

[wkania]

I'd like to, but I don't know where we could put it to reach the maximum number of people.

During https://live.symfony.com/