Can I set errors of specific field when onSubmit failed?

[FourwingsY]

Let's say, in Login,
API could answer : "Your Password is wrong"

Then I want to display this message as a field error.

then how could I do that?

I tried this, and this works.
But Is this the proper way?

const form = useForm({
  onSubmit: async ({ value, formApi }) => {
    try {
      await submit(value)
    } catch (e) {
      // using setFieldMeta
      formApi.setFieldMeta("password", { 
        ...formApi.getFieldMeta("password")!, 
        errorMap: { onSubmit: "Unknown Error Occurred" },
      })

      // or this
      formApi.fieldInfo.password.instance?.setErrorMap({ onSubmit: "Unknown Error Occurred" });
    }
  }
})

[Balastrong]

You can return an object from the form validator.onSubmitAsync that automatically spreads the errors in the fields, see the docs.

return {
  fields: {
    password: "Unknown Error Occurred"
  },
}

[FourwingsY]

I meant, it is error returned by "submit"
and there is no API for validating usecase only.

Do I should submit using validator.onSubmitAsync, without onSubmit?

[FourwingsY]

This is same discussion of #623

[FourwingsY]

Summarizing answer from the thread

tldr; "SUBMIT IN A VALIDATOR", if your call returns validation results.

Submit flow of tanstack/form

• Run validators.onSubmit for sync validation
• Run validators.onSubmitAsync for async validation
• Run onSubmit if both don't have errors

So If my server is running validation on request, (even if it commits transaction)

• That should be inside of validators.onSubmitAsync
• then onSubmit is handled as a callback of successful submit.