type FormState.ValidationMode

A type that determines how form field validation is triggered.

type ValidationMode = "demand" | "auto" | "immediate";

demand — Fields are only validated when FormState.validate() is called explicitly. The FormState.set() method never triggers validation.
auto — Fields are validated automatically by FormState.set() after FormState.validate() has been called at least once. Before that, set() does not validate. This is the default mode.
immediate — Fields are validated immediately by FormState.set() on every change, except when setting an undefined field to an empty string.

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