Question

我正在使用Yesod进行用户注册过程。该计划是向新注册的用户发送激活其帐户的电子邮件。我试图创建一个小部件，其中包含一个Typed-Url回到接受电子邮件确认码的路由。

--- template.hamlet

<h3>Email Change Confirmation
<p>A new email address has been set for your account with Dropship Center.
    $case ecrType
        $of New
            <p>Please click
            <a href=@{UserConfirmationR}/#{code}>here
            to confirm.

--- User.hs

import           Text.Blaze.Html.Renderer.Text (renderHtml)

postUserR :: Handler Value
postUserR = do
    val <- parseJsonBody :: Handler (Result Registration)
    case val of
        Error e -> return $ object [ "error" .= e ]
        Success Registration{..} -> do

        ...database actions...

        let ecrType = New
            code    = (ecrNewConfirm ecr)
            html    = renderHtml $ $(widgetFile "ecr-message")

        ...send confirmation email using "html" as the message body...

不幸的是，我一直收到以下错误。这是我无法弄清楚的。

Handler/User.hs:84:46:
Couldn't match type `WidgetT site0 m0'
              with `blaze-markup-0.6.0.0:Text.Blaze.Internal.MarkupM'
Expected type: blaze-markup-0.6.0.0:Text.Blaze.Internal.MarkupM ()
  Actual type: WidgetT site0 m0 ()
In the return type of a call of `asWidgetT . toWidget'
In a stmt of a 'do' block:
  (asWidgetT . toWidget)
    ((blaze-markup-0.6.0.0:Text.Blaze.Internal.preEscapedText . pack)
       "<h3>Email Change Confirmation</h3>\
       \<p>A new email address has been set for your account with Dropship Center.")
In a stmt of a 'do' block:
  do { (asWidgetT . toWidget)
         ((blaze-markup-0.6.0.0:Text.Blaze.Internal.preEscapedText . pack)
            "<h3>Email Change Confirmation</h3>\
            \<p>A new email address has been set for your account with Dropship Center.");
       case ecrType of {
         New -> do { ... }
         Old -> do { ... } };
       (asWidgetT . toWidget)
         ((blaze-markup-0.6.0.0:Text.Blaze.Internal.preEscapedText . pack)
            "</p>") }

是否有一些中间阶段将Widget转换为Html类型？

Answer 1

要解压缩Widget，您需要使用widgetToPageContent。但是，这可能不是你想要的，因为我怀疑你打算在电子邮件中使用CSS和Javascript。相反，您可能希望使用hamletFile，它只能生成HTML。您需要传入一个URL呈现函数，您可以使用getUrlRenderParams来获取该函数。咒语将类似于：

renderer <- getUrlRenderer
let html = $(hamletFile "filepath.hamlet") renderer

在Yesod中使用Typed-Urls构建电子邮件

1 个答案: