Function UserStructLevelValidation

_examples/struct-level/main.go:167–177

UserStructLevelValidation contains custom struct level validations that don't always make sense at the field validation level. For example, this function validates that either FirstName or LastName exist; could have done that with a custom field validation but then would have had to add it to both f

(sl validator.StructLevel)

// hooks right into validator and you can combine with validation tags and still have a
// common error output format.
func UserStructLevelValidation(sl validator.StructLevel) {

	user := sl.Current().Interface().(User)

	if len(user.FirstName) == 0 && len(user.LastName) == 0 {
		sl.ReportError(user.FirstName, "fname", "FirstName", "fnameorlname", "")
		sl.ReportError(user.LastName, "lname", "LastName", "fnameorlname", "")
	}

	// plus can do more, even with different tag than "fnameorlname"
}