show placeholder again when resetting select options

[RwwL]

Working with a standard HTML <select> and useController: if the user makes a selection then changes another field which requires that the select options change, I'm finding that I can't get the select to show its placeholder again. The UI always shows the first option of the new options, even if I've called resetField or setValue first — but it's just showing in the UI, the form does have the field now set to null or undefined, so it creates a UX disconnect (user thinks a selection is made but it isn't).

For example, in a typical form with country and state field names (where the state can actually be province/region/whatever, switched out depending on the country).

  const selectedCountry = watch('country');
  const selectedDivision = watch('state');

  useEffect(() => {
    if (!isLoadingCountries) {
      const currentCountry = countries.find((country) => country.code === selectedCountry)
      const currentDivisions = currentCountry?.divisions;
      if (currentDivisions) {
        const divisionCodes = currentDivisions.map(d => d.code);
        if (selectedDivision && !divisionCodes.includes(selectedDivision)) {
          resetField('state', { defaultValue: undefined });
          // I've also tried:
          // resetField('state', { defaultValue: null });
          // setValue('state', null);
          // setValue('state', undefined);
        }
        setDivisions(currentDivisions);
        // I've also tried those setValue/resetField attempts from above after setDivisions
      }
    }
  }, [countries, selectedCountry, selectedDivision, isLoadingCountries, resetField]);

Any suggestions how I can get the placeholder to show in this case?

[Moshyfawn]

undefined is not a valid field value.

[RwwL]

OK, thanks, that's good to know, but I've also been trying to use null as noted in the post, any thoughts on that (or on some other way to get to the desired result)?

[Bilal-Abubakari]

@RwwL Did you ever find a solution to this?

[RwwL]

@Bilal-Abubakari Nope, never did, unfortunately.

[Bilal-Abubakari]

@RwwL when I used empty string it worked for me