9.0 Should `_hidden.defaultValue = true` work?

[mhsdesign]

properties:
    _hidden:
      defaultValue: true

this seems to work in 8.3 (someone in slack tried it)

related #4208

[Nikdro]

If it's not the desired way and will be removed: We should keep some kind of functionality, to configure the defaultValue for hidden :)

[kdambekalns]

Accessing those by prefixing with _ has always worked, is used throughout the core and has explicit support in the code.

[mhsdesign]

well but hidden is not a setter anymore in neos 9 - thats why it worked before

[kdambekalns]

Well, but were all places using that adjusted? Even if so, do other similar properties still work? Any YAML out there using this would break…

[bwaidelich]

Just to avoid confusion: Does this still work with Neos 9 (currently) via some Neos UI magic?
If so, we should keep support until we have a proper alternative
If not, anyone is free to re-implement it – but it's probably too late for a 1st beta

[mhsdesign]

this is also related to #4550 as we could introduce a generic yaml option for default subtree tags on a node:

MyNode:
  subtreeTags:
    disabled: true

[mhsdesign]

we could make this a NodeTemplates feature (again) see pr

'Flowpack.NodeTemplates:Content.Hidden':
   superTypes:
     'Neos.Neos:Content': true
   options:
     template:
       disabled: true

As i stated in the cr weekly: I dont think we need out of the box support for this right away for neos 9.

And with #4821 it either way wont be possible to disable tethered nodes (for integrity).