React Hook Form dynamic required

Question

I'm trying to make a form with two fields using react hook form where the required value of the text field depends on the value of the select drop down.

Here is my code:

  const { handleSubmit, control, errors } = useForm();

  const [isPickupPoint, togglePickupPoint] = useState(false);

  const handleDestinationTypeChange: EventFunction = ([selected]) => {
    togglePickupPoint(selected.value === "PICKUP_POINT");
    return selected;
  };

            <Grid item xs={6}>
              <InputLabel>Destination type</InputLabel>
              <Controller
                as={Select}
                name="destinationType"
                control={control}
                options={[
                  { label: "Pickup point", value: "PICKUP_POINT" },
                  { label: "Shop", value: "SHOP" },
                ]}
                rules={{ required: true }}
                onChange={handleDestinationTypeChange}
              />
              {errors.destinationType && (
                <ErrorLabel>This field is required</ErrorLabel>
              )}
            </Grid>
            <Grid item xs={6}>
              <Controller
                as={
                  <TextField
                    label="Pickup Point ID"
                    fullWidth={true}
                    disabled={!isPickupPoint}
                  />
                }
                control={control}
                name="pickupPointId"
                rules={{ required: isPickupPoint }}
              />
              {errors.pickupPointId && (
                <ErrorLabel>This field is required</ErrorLabel>
              )}
            </Grid>
            <Grid item xs={12}>
              <Button
                onClick={onSubmit}
                variant={"contained"}
                color={"primary"}
                type="submit"
              >
                Save
              </Button>
            </Grid>

The isPickupPoint flag changes properly because the disabled prop of the textfield works fine. Only when the PICKUP_POINT option is selected the text field is active. But the required prop is not working, it is always false. When I try submitting the form when its empty the destinationType error label appears, but when I try to submit the form with the PICKUP_POINT option and empty pickupPointId field it passes with no errors.

How can I make this dynamic required prop work?

Answer 1

Based on the code here, it looks like isPickUpPoint is working as expected since it works for disable. Since you are using the same property for required, it should flow through. I would suspect that the bug may lie in your Controller component. I would take a look there and make sure that the property is what you expected to be.

Also for disabled the condition is !isPickUpPoint, so it will trigger when it's false.

For required the condition is isPickUpPoint so it will trigger when it's true.

That's also a bit of a disconnect since it looks like it's the same input.