Minor. Puny attempts to resuse corrections table in several ways.

src/Foundation.hs

@@ -40,6 +40,8 @@ import Data.ByteArray (convert)
 import Crypto.Hash (Digest, SHAKE256)
 import Crypto.Hash.Conduit (sinkHash)
 
+import qualified Data.CryptoID (CryptoID) -- for DisplayAble instance only
+
 import qualified Data.ByteString.Base64.URL as Base64 (encode)
 
 import Data.ByteString (ByteString)
@@ -73,13 +75,19 @@ import Handler.Utils.DateTime
 import Control.Lens
 import Utils.Lens
 
--- -- TODO: Move me to appropriate Place
+
+-- -- TODO: Move the following to the appropriate place, if DisplayAble is kept
 instance DisplayAble TermId where
   display = termToText . unTermKey
 
 instance DisplayAble UTCTime where
   display = pack . formatTimeGerDT2 -- default Time Format to be used: 00.00.00 00:00
 
+instance (PathPiece b) => DisplayAble (Data.CryptoID.CryptoID a b) where
+  display = toPathPiece -- requires import of Data.CryptoID here
+-- -- MOVE ABOVE
+
+
 -- infixl 9 :$:
 -- pattern a :$: b = a b
 

src/Handler/Corrections.hs

@@ -15,16 +15,16 @@
 module Handler.Corrections where
 
 import Import
-import System.FilePath (takeFileName)
+-- import System.FilePath (takeFileName)
 
 import Handler.Utils
 -- import Handler.Utils.Zip
 
-import qualified Data.Set as Set
+-- import qualified Data.Set as Set
-import qualified Data.Map as Map
+-- import qualified Data.Map as Map
 
 -- import Data.Time
-import qualified Data.Text as T
+-- import qualified Data.Text as T
 -- import Data.Function ((&))
 --
 import Colonnade hiding (fromMaybe, singleton)
@@ -34,7 +34,7 @@ import Yesod.Colonnade
 -- import qualified Data.Conduit.List as C
 
 import qualified Database.Esqueleto as E
-import qualified Database.Esqueleto.Internal.Sql as E
+-- import qualified Database.Esqueleto.Internal.Sql as E
 
 import Control.Lens
 -- import Control.Monad.Writer (MonadWriter(..), execWriterT)
@@ -42,14 +42,25 @@ import Control.Lens
 -- import Network.Mime
 
 
+ratedBy :: E.Esqueleto query expr backend =>
+            expr (Entity Submission) -> Key User -> expr (E.Value Bool)
+ratedBy submission uid = submission E.^. SubmissionRatingBy E.==. E.just (E.val uid)
+
+courseIs :: E.Esqueleto query expr backend =>
+            expr (Entity Course) -> Key Course -> expr (E.Value Bool)
+courseIs course cid = course E.^. CourseId E.==. E.val cid
+
 getCorrectionsR :: Handler Html
 getCorrectionsR = do
   uid <- requireAuthId
-  let tableData :: _ -> E.SqlQuery _
+  let tableData :: E.InnerJoin (E.InnerJoin (E.SqlExpr (Entity Course))
+                                            (E.SqlExpr (Entity Sheet )))
+                               (E.SqlExpr (Entity Submission))
+                    -> E.SqlQuery _
       tableData (course `E.InnerJoin` sheet `E.InnerJoin` submission) = do
         E.on $ sheet  E.^. SheetId  E.==. submission E.^. SubmissionSheet
         E.on $ course E.^. CourseId E.==. sheet      E.^. SheetCourse
-        E.where_ $ submission E.^. SubmissionRatingBy E.==. E.just (E.val uid)
+        E.where_ $ submission `ratedBy` uid
         let crse =  ( course E.^. CourseName      :: E.SqlExpr (E.Value Text)
                     , course E.^. CourseShorthand
                     , course E.^. CourseTerm
@@ -65,15 +76,15 @@ getCorrectionsR = do
         [ dbRow
         , sortable (Just "term") (i18nCell MsgTerm) $ \DBRow{ dbrOutput=(_, _, course) } ->
             -- cell [whamlet| _{untermKey $ course ^. _3}|]   -- lange, internationale Semester
-            textCell $ termToText $ unTermKey $ E.unValue $ $(projNI 4 3) course  -- kurze Semsterkürzel
+            textCell $ termToText $ unTermKey $ E.unValue $ course ^. _3 -- kurze Semsterkürzel
         , sortable (Just "course") (i18nCell MsgCourse) $ \DBRow{ dbrOutput=(_, _, course) } ->
             textCell $ E.unValue $ course ^. _2
         , sortable (Just "sheet") (i18nCell MsgSheet) $ \DBRow{ dbrOutput=(_, sheet, _) } ->
             textCell $ sheetName $ entityVal sheet
         , sortable Nothing (i18nCell MsgSubmission) $ \DBRow{ dbrOutput=(submission, sheet, course) } ->
             cell $ do
-              let tid = E.unValue $ $(projNI 4 3) course
+              let tid = E.unValue $ course ^. _3
-                  csh = E.unValue $ $(projNI 4 2) course
+                  csh = E.unValue $ course ^. _2
                   shn = sheetName $ entityVal sheet
               cid <- encrypt (entityKey submission :: SubmissionId)
               [whamlet|<a href=@{CSheetR tid csh shn (SubmissionR cid)}>#{display cid}|]

src/Handler/Utils/Table/Pagination.hs

@@ -106,7 +106,7 @@ data DBRow r = DBRow
   }
 
 dbRow :: (Headedness h) => Colonnade h (DBRow r) (Cell site)
-dbRow = Colonnade.singleton (headednessPure "nr") $ \DBRow{ dbrIndex } ->
+dbRow = Colonnade.singleton (headednessPure "Nr") $ \DBRow{ dbrIndex } ->
   textCell $ tshow dbrIndex
 
 class DBOutput r r' where

src/Utils/Common.hs

@@ -16,7 +16,7 @@ import Language.Haskell.TH
 -- Tuples --
 ------------
 
-
+-- Alternatively uses lenses: "^. _3" projects the 3rd component of an n-tuple for any n >=3, requires import Control.Lens
 projNI :: Int -> Int -> ExpQ -- generic projection gives I-th element of N-tuple, i.e. snd3 = $(projNI 3 2)  --ghci -fth
 -- $(projN n m) :: (t1,..,tn) -> tm (for m<=n)
 projNI n i = lamE [pat] rhs