Conditional subelement within custom composite webform element

Question

I have a webform that has a custom composite element; let's name it composite_name.

Within that custom composite, I have element_a, element_b, and element_c.

Is it possible to make element_c visible only when a value is entered in either element_a or element_b, by editing the composite element in the Webform UI?

I tried putting this in the custom properties for element_c, but it does not work:

states:
  visible:
    - ':input[name=["composite_name"]["element_a"]]':
        filled: true
    - or
    - ':input[name=["composite_name"]["element_b"]]':
        filled: true

I also tried a few variations on that, with no success. I don't know whether I just have some punctuation out of place or something.

It looks like I could make the condition happen using a custom module (following the webform_example_composite module's code), but I'm hoping to configure it in the UI.

Answer 1

Conditions need to be set per row.

The webform_example_composite.module, included w/ Webform, shows how to do this via \Drupal\webform_example_composite\Element\WebformExampleComposite