Haskell 是根据应用程序设置进行硬编码身份验证

我正在尝试将硬编码身份验证设置为依赖于来自Yesod数据库的

config/settings.yml

中指定的登录信息。我编写了以下代码：

instance YesodAuthHardcoded App where
    validatePassword u = do
        app <- getYesod
        let user = appUser $ appSettings app
        return . validPassword user u . fromString . unpack
    doesUserNameExist = do
        app <- getYesod
        return . isJust . lookupUser app

的原型验证密码

：

和

AuthHandler

：

最后

getYesod

：

从这些定义看来，应该有一种方法可以让我从

AuthHandler

monad调用

getYesod

，但我不知道如何调用

---

编辑： 我已将

yesod

及其支架更新为最新版本。我还修改了

validatePassword

，如下所示：

validatePassword u = do
    app <- liftHandler . getYesod
    let user = appUser $ appSettings app
    return . validPassword user u . fromString . unpack

validatePassword u=do
app错误源于我试图修改
Yesod.Auth.Hardcoded
模块给出的代码段。我引入了一个与省略的参数冲突的
do
符号。指定参数可以解决问题，代码将变为：

instance YesodAuthHardcoded App where
    validatePassword u p = do
        app <- getYesod
        let user = appUser $ appSettings app
        return . validPassword user u . fromString $ unpack p
    doesUserNameExist u = do
        app <- getYesod
        return . isJust $ lookupUser app u

实例YesDouthHardcoded应用程序，其中
验证密码u p=do
我怀疑你需要在某处插入
liftHandler
或
liftSubHandler
。
type MonadAuthHandler master m = (MonadHandler m, YesodAuth master, master ~ HandlerSite m, Auth ~ SubHandlerSite m, MonadUnliftIO m)

type AuthHandler master a = forall m. MonadAuthHandler master m => m a 

getYesod :: MonadHandler m => m (HandlerSite m)

validatePassword u = do
    app <- liftHandler . getYesod
    let user = appUser $ appSettings app
    return . validPassword user u . fromString . unpack

    • Couldn't match type ‘m1 a1’ with ‘App’
      Expected type: HandlerFor (HandlerSite m1) a1 -> App
        Actual type: HandlerFor (HandlerSite m1) a1 -> m1 a1
    • In the first argument of ‘(.)’, namely ‘liftHandler’
      In a stmt of a 'do' block: app <- liftHandler . getYesod
      In the expression:
        do app <- liftHandler . getYesod
           let user = appUser $ appSettings app
           return . validPassword user u . fromString . unpack
    |
259 |         app <- liftHandler . getYesod
    |

instance YesodAuthHardcoded App where
    validatePassword u p = do
        app <- getYesod
        let user = appUser $ appSettings app
        return . validPassword user u . fromString $ unpack p
    doesUserNameExist u = do
        app <- getYesod
        return . isJust $ lookupUser app u