templateshaskellghcyesodhamlet

How to import Shakespearean Templates in Yesod?


I was using QuasiQuotations in Yesod, and everything worked fine. BUT my file became very large and not nice to look at. Also, my TextEditor does not highlight this syntax correctly. That is why is split my files like so:

getHomeR :: Handler Html
getHomeR = do
    webSockets chatApp
    defaultLayout $ do
        $(luciusFile "templates/chat.lucius")
        $(juliusFile "templates/chat.julius")
        $(hamletFile "templates/chat.hamlet")

If this is wrong, please do tell. Doing runghc myFile.hs throws many errors like this:

chat_new.hs:115:9:
    Couldn't match expected type ‘t0 -> Css’
                with actual type ‘WidgetT App IO a0’
    The lambda expression ‘\ _render_ajFK
                             -> (shakespeare-2.0.7:Text.Css.CssNoWhitespace . (foldr ($) ...))
                                  ...’
    has one argument,
    but its type ‘WidgetT App IO a0’ has none
    In a stmt of a 'do' block:
      \ _render_ajFK
      ...

And this.

chat_new.hs:116:9:
    Couldn't match type ‘(url0 -> [(Text, Text)] -> Text)
                         -> Javascript’
                   with ‘WidgetT App IO a1’
    Expected type: WidgetT App IO a1
      Actual type: JavascriptUrl url0
    Probable cause: ‘asJavascriptUrl’ is applied to too few arguments
    ...

And also one for the HTML (Hamlet).

Thus, one per template.


Solution

  • It seems that hamletFile and others treat templates as self-contained, while yours are referencing something from each other. You can play with order of *File calls, or use widgetFile* from Yesod.Default.Util module:

    $(widgetFileNoReload def "chat")
    

    The Reload variant is useful for development - it would make yesod devel to watch for file changes and reload them.