In YAML, the 'name' argument of useAttributeAsKey() has a special meaning and refers to the key of the map (sf_connection and default in this example). If a child node was defined for the connections node with the key name, then that key of the map would be lost.

Seehttps://symfony.com/doc/current/components/config/definition.html#array-node-options

@smnandre Well yes, it does make sense in the example, and in some other cases such asscoped_clients, but it still doesn't make sense for thedefault_context. You cannot do, for example, something like:

framework:serializer:default_context:            -name:oneenable_max_depth:trueyaml_indentation:2            -name:twoenable_max_depth:trueyaml_indentation:2

As i read it you can do the following:

framework:serializer:default_context:foo:barblop:blipname:name

@smnandre You can still do that even with this change.

As of writing this, there is an inconsistency: if only one file provides the configuration in question, the keys (i.e. sf_connection and default) are not lost. But if more than one file provides the configuration, the keys are lost as described above.

@smnandre Sorry, I'm not sure what the point of your last response was.

Let's change this on 7.1, this is not a bugfix to me.

@nicolas-grekas Done

Thank you@HypeMC.

@smnandre Sorry, I'm not sure what the point of your last response was.

@HypeMC I've spend a looong time trying to reproduce a case where those keys were lost, justifiying this call... and failed massively. Will bring concrete evidence (if it exists) before commenting next time.. Sorry for that, lesson learned.

@smnandre No worries, better safe than sorry, thanks for investigating 😄

Let's change this on 7.1, this is not a bugfix to me.

A test on documentation examples revealed that this does create a weird situation when using the config builders.

TheuseAttributeAsKey signals the config builders that we expect a mapping with a key. Which creates a method with 2 arguments rather than 1.

E.g. the following snippet does not work on 6.4:

returnstaticfunction (FrameworkConfig$framework):void {$framework->serializer()        ->defaultContext(['allow_extra_attributes' =>false,        ])    ;};

And a user has to do something like:

returnstaticfunction (FrameworkConfig$framework):void {$framework->serializer()        ->defaultContext('can be anything as this is not used', ['allow_extra_attributes' =>false,        ])    ;};

I think we can consider this a bugfix for 6.4, what do you think?