Ensure a value is absent.

Vex uses the Vex.Blank protocol to determine "absence." Notably, empty strings and collections are considered absent.

Options

• :message: Optional. A custom error message. May be in EEx format and use the fields described in "Custom Error Messages," below.

Examples

iex> Vex.Validators.Absence.validate(1, true)
{:error, "must be absent"}
iex> Vex.Validators.Absence.validate(nil, true)
:ok
iex> Vex.Validators.Absence.validate(false, true)
:ok
iex> Vex.Validators.Absence.validate("", true)
:ok
iex> Vex.Validators.Absence.validate([], true)
:ok
iex> Vex.Validators.Absence.validate([], true)
:ok
iex> Vex.Validators.Absence.validate([1], true)
{:error, "must be absent"}
iex> Vex.Validators.Absence.validate({1}, true)
{:error, "must be absent"}

Custom Error Messages

Custom error messages (in EEx format), provided as :message, can use the following values:

iex> Vex.Validators.Absence.__validator__(:message_fields)
[value: "The bad value"]

An example:

iex> Vex.Validators.Absence.validate([1], message: "can't be <%= inspect value %>")
{:error, "can't be [1]"}