Validators¶

A validator is a function that checks a value and returns whether it is valid, and a message when it is not:

type Validator = (value: any) -> (boolean, string?)

TextField, ChoiceGroup, Select and MultiSelect take a list of them in Validators. They are checked in order, and the first one that fails shows its message.

local V = Pantheon.Validators

C.TextField(scope, {
    Label = "Username",
    Validators = { V.required(), V.minLength(3), V.maxLength(20) },
})

Functions¶

Each function that makes a validator takes an optional message, which replaces the default.

Name	Passes when	Default message
`required(message?)`	The value is not `nil`, an empty string or an empty list.	`Required`
`minLength(n, message?)`	The text has at least `n` characters.	`At least n characters`
`maxLength(n, message?)`	The text has at most `n` characters.	`At most n characters`
`email(message?)`	The text looks like an email address. An empty text passes.	`Enter a valid email`
`pattern(pattern, message?)`	The text matches a Luau pattern. An empty text passes.	`Invalid format`
`numberRange(min?, max?, message?)`	The value is a number between `min` and `max`.	`Out of range`
`all(list)`	Every validator in `list` passes.	The message of the first that fails
`run(list?, value)`	Returns the result of the first validator in `list` that fails, or `true` when they all pass.

An empty text passes email and pattern, so a field that may be left empty does not need a special case. Add required for a field that may not be.