method
EmailField.DefaultFrom
Use a callback to choose the initial email address when this field is omitted.
Arguments
| Argument | Type | Description |
|---|---|---|
callback | DefaultFunc[string] | A non-nil function that receives operation.DefaultContext and returns an operation.Value[string] plus an error. Return Present(value) to supply a value, Empty to supply no default, or an error to stop the operation. |
Returns
A new EmailField with this callback as its only default. The original field is unchanged; this replaces any previous Default or DefaultFrom setting.
EmailFieldHow it works
The callback runs on the server when omitted input is eligible for initialization. It does not prefill an unsaved form or refill a field on every edit. See the default values guide for new objects, repeated rows, and locales.
The returned string must still pass email validation.
Full signature
func (f EmailField) DefaultFrom(callback DefaultFunc[string]) EmailFieldRelated types
EmailFieldEmailField configures a field that stores and validates an email address.
DefaultFuncDefaultFunc supplies a server-side initial value for an eligible omitted field. Root and Siblings are snapshots at initialization; Prior is the persisted enclosing object or stable row (empty for new rows). ID may be empty. Locale is exact and Local retains authorization, cancellation and the active transaction. Present supplies a value, including zero values; Empty leaves it without a default. An error stops the operation. Returned values still pass validation. Defaults do not prefill an unsaved admin form and do not run on ordinary edits to an existing scope. Callbacks must not depend on other dynamic defaults or perform irreversible side effects: separate requests or retries can run again.