Feeding.hs

{-# LANGUAGE TupleSections, OverloadedStrings #-}
module Handler.Feeding where

import Import
import Network.HTTP.Types (status201, status204, status200)

{- This module contains the Feeding resource -}

getFeedingR :: FeedingId -> Handler RepJson
getFeedingR fid = runDB (get404 fid) >>= jsonToRepJson . Entity fid

deleteFeedingR :: FeedingId -> Handler ()
deleteFeedingR fid = do --incomming Id is Base64, mongo expects Base16
                  runDB (delete fid)
                  sendResponseStatus status200 ()

putFeedingR :: FeedingId -> Handler ()
putFeedingR fid =  do --incomming Id is Base64, mongo expects Base16
                feeding <- parseJsonBody_
                runDB $ replace fid feeding
                sendResponseStatus status200 ()

postFeedingsR :: Handler RepJson
postFeedingsR = do
      muser <- maybeAuth
      parsedFeeding <- parseJsonBody_ --get content as JSON
      fid <- runDB $ insert parsedFeeding --store in mongo
      u <- runDB $ update fid [ UserId =. muser] --link the feeding to the user
      sendResponseCreated $ FeedingR fid --return the id

getFeedingsR :: Handler RepJson
getFeedingsR = runDB (selectList [] [Desc FeedingDate, Desc FeedingTime]) >>= jsonToRepJson . asFeedingEntities
    where
      asFeedingEntities :: [Entity Feeding] -> [Entity Feeding]
      asFeedingEntities = id

Line 28 is wrong according to the all-knowing haskell compiler:
Handler/Feeding.hs:28:20: Couldn't match type YesodPersistBackend master0' withmongoDB-1.2.0:Database.MongoDB.Query.Action' Expected type: YesodDB sub0 master0 () Actual type: mongoDB-1.2.0:Database.MongoDB.Query.Action (GHandler sub0 master0) () In the return type of a call of update' In the second argument of($)', namely `update fid [UserId =. muser]' In a stmt of a 'do' block: u <- runDB $ update fid [UserId =. muser]

Handler/Feeding.hs:28:43:
Couldn't match expected type Key backend0 (UserGeneric backend0)' with actual typeMaybe (Entity val0)'
In the second argument of (=.)', namelymuser'
In the expression: UserId =. muser
In the second argument of update', namely[UserId =. muser]'