How to manage validation of required inputs when they are reusable elements?

Hello everyone, I hope you are well.

I would like to hear from you how you manage these cases when we use inputs wrapped in Reusable Elements (for example when we create our own custom dropdowns or searchbox) and need to validate them when triggering an action such as creating or updating something.

We know that when a common input is required and is part of an action, if it is empty when the trigger is started, the invalid value style (This input isn't valid) will be highlighted in the input and the action will not be triggered. How to do the same with inputs wrapped in Reusable Elements since we need to work with Custom States. I know we can insert some conditionals in the action itself to not be trigerred when the Custom State is empty or something like that, but what about the invalid value style?

Thank you very much in advance.

Conditionals on the input that reference the custom state to change the inputs design