Formal: custom error msg

[polar fulcrum]

Hey everyone,

I am playing around with the formal library and I was wondering what was the recommanded way to add an error message to a specifi action.

For example how could I add "password must be at least 3 characters" ?

I tried to look at the language function but that doesn't seem very ergonomic ?

fn signup_form() -> Form(Signup) {
  form.new({
    use email <- form.field("email", {
      form.parse_email
    })
    use password <- form.field("password", {
      form.parse_string
      |> form.check_string_length_more_than(3) // how can I add a specific error
                                               // message if this guard is failing ?
    })
    use _ <- form.field("confirm", {
      form.parse_string
      |> form.check_confirms(password)
    })
    SignUp(email: email, password: password)
  })
}

[rustic moon]

Formal errors don't have the name of the field in them

So you'd add the name of the field in your HTML if you want it

Otherwise that's the error already with the default translator for English

If you want to specify different a different translation for the built in errors then you want to use language to specify a custom translator function

If you want to add a new error that is not one of the built in ones then you can use check to add your own validation logic and custom error

But that's not just a new translation, as I believe you want from your question

[polar fulcrum]

Thanks Louis for the help, that cleared it 🙌

[rustic moon]

np!

The definition of the en_us translator may be a useful reference

pub fn en_us(error: FieldError) -> String {
  case error {
    MustBeColour -> "must be a hex color code"
    _ -> en_gb(error)
  }
}