[Question] Is it possible to have optional fields? about modular-forms

[fabian-hiller]

If you provide me your code via StackBlitz I can try to investigate it. Here is a template: https://stackblitz.com/edit/modular-forms-react?file=src/routes/login.tsx

[FujishigeTemma]

Make sense. Thank you!

[fabian-hiller]

You wrote "items.0.data.max_number" instead of "items.0.data.max_select", does this cause the problem? Also, when using arrays, I recommend using our specialized array functions. In your case you should probably use replace. Read more here: https://modularforms.dev/qwik/guides/field-arrays#use-array-methods

[FujishigeTemma]

You wrote "items.0.data.max_number" instead of "items.0.data.max_select", does this cause the problem?

Sorry, I just made a mistake when I simplified my code for reproduction (fixed). So it was not in my actual code.

Also, when using arrays, I recommend using our specialized array functions. In your case you should probably use replace.

Thank you for your advice! But unfortunately I got almost same error. For me, it seems that, with a object { x: string, y: number } | { x: string, z: boolean }, inferred type of x is correct but types of y, z become never.

[FujishigeTemma]

Sure! Here is a reproduction from template: https://stackblitz.com/edit/modular-forms-react-7twxqr?file=src%2Froutes%2Freproduction.tsx

[fabian-hiller]

Thank you! I plan to have a look on it on the weekend.

[fabian-hiller]

It seems that this is the normal behavior of TypeScript when working with unions. The y doesn't exist in every case, which is why TypeScript displays an error. A workaround might be to use setValues: https://modularforms.dev/react/api/setValues

setValues(u, { x: 'ok', y: 'also ok' });
setValues(v, { data: { x: 'ok', y: 'also ok' } });