IHP:如何使用来自其他字段的值验证字段

module Web.Validation.Article where

import IHP.Prelude
import IHP.ModelSupport
import IHP.ValidationSupport
import Generated.Types

data Article = Article
    { title :: Text
    , content :: Text
    , isPublished :: Bool
    , publishDate :: Maybe UTCTime
    }
    deriving (Eq, Show)

instance ValidateSchema Article where
    validateSchema article =
        article
            |> validateField #title nonEmpty
            |> validateField #content nonEmpty
            |> validateField #publishDate (validateIf #isPublished isTrue validateDate)

validateIf :: (a -> Bool) -> (a -> Validator) -> a -> Validator
validateIf condition validator value =
    if condition value
        then validator value
        else Success

validateDate :: UTCTime -> ValidatorResult
validateDate date =
    if date > getCurrentTime
        then Failure "Publish date cannot be in the future"
        else Success