Errors & Output

ToError() and ToValgoError()

• ToError() returns a standard error.
• ToValgoError() returns *valgo.Error for structured access.

val := v.Is(v.String("", "name").Not().Blank())

if err := val.ToError(); err != nil {
  return err
}

if errInfo := val.ToValgoError(); errInfo != nil {
  for field, valueErr := range errInfo.Errors() {
    _ = field
    _ = valueErr.Messages()
  }
}

AddErrorMessage(name, message)

Attach an error without a validator (useful for “entity-level” errors).

val := v.Is(
  v.String(a.City, "city").Not().Blank(),
  v.String(a.Street, "street").Not().Blank(),
)

if !val.Valid() {
  val.AddErrorMessage("address", "The address is wrong!")
}

Merge(other)

Merge two sessions to reuse validation logic.

val := v.Is(
  v.String(r.Name, "name").Not().Blank(),
  v.String(r.Status, "status").Not().Blank(),
)

val.Merge(validatePreStatus(r.Status))

Custom JSON output (Factory)

If you need a different JSON shape, use a Factory with a custom marshal function. See Localization & Factory.