Warning: Undefined array key "wrappers"

I rolled back to 3.03, added custom field and then updated to 3.1, cleared cache and rendered existing node, resaved, etc... but wasn't able to reproduce. Anyhow, i added a default value in case it isn't set for some reason so please try this patch against 3.1 and clear the cache and see if it resolves for you. Please report back so we can merge in or refactor if necessary.

Oh, i see there were warnings in the logs. Just warnings to harmless but just the same, the patch just get rid of those. Ultimately resaving the field settings in manage display will also set the new values to config even if empty.

You should see something like this in config export for the field after resaving:

  field_custom_field:
    type: custom_formatter
    label: above
    settings:
      fields:
        title:
          format_type: string
          wrappers:
            field_wrapper_tag: ''
            field_wrapper_classes: ''
            field_tag: ''
            field_classes: ''
            label_tag: ''
            label_classes: ''

Okay, the patch did resolve the warnings. Thanks for the fast turnaround!

I also see the new config item after actually editing/saving the formatter settings per your instructions in the other issue 🐛 Errors when displaying Entity Reference field as a block in block layout Active .

We also use fences, so I'm curious to see if/how these new wrappers might interact with that module.

Cool, thanks for the review. This setting works in conjunction with fences module but has no dependency or interaction with it. It basically does the same thing but at the subfield level so you can have full control over the output if desired.

Thanks for the info on wrappers. And I just wanted to say, Custom Field really is an excellent contribution — thanks for your work!