Show pagesize widget iff rowCount is larger than minimum pagesize

src/Handler/Utils/Table/Pagination.hs

@@ -602,11 +602,11 @@ dbTable PSValidator{..} dbtable@DBTable{ dbtIdent = dbtIdent'@(toPathPiece -> db
         | otherwise
           = def
 
+      referencePagesize = psLimit . snd . runPSValidator dbtable $ Just prevPi
+
   (((filterRes, filterWdgt), filterEnc), ((pagesizeRes, pagesizeWdgt), pagesizeEnc)) <- mdo
     (filterRes'@((filterRes, _), _)) <- runFormGet . identForm FIDDBTableFilter . addPIHiddenField dbtable (prevPi & _piFilter .~ Nothing & _piPage .~ Nothing & _piLimit .~ (formResult' pagesizeRes <|> piLimit prevPi)) . renderAForm FormDBTableFilter $ dbtFilterUI (piFilter prevPi)
 
-    let referencePagesize = psLimit . snd . runPSValidator dbtable $ Just prevPi
-
     (pagesizeRes'@((pagesizeRes, _), _)) <- lift . runFormGet . identForm FIDDBTablePagesize . addPIHiddenField dbtable (prevPi & _piPage .~ Nothing & _piLimit .~ Nothing & _piFilter .~ (formResult' filterRes <|> piFilter prevPi)) . renderAForm FormDBTablePagesize $
           areq (pagesizeField referencePagesize) (fslI MsgDBTablePagesize & addAutosubmit & addName (wIdent "pagesize") & addClass "select--pagesize") (Just referencePagesize)
       <*  autosubmitButton
@@ -760,6 +760,15 @@ dbColonnade :: (Headedness h, Monoid x)
             -> Colonnade h r (DBCell (ReaderT SqlBackend (HandlerT UniWorX IO)) x)
 dbColonnade = id
 
+pagesizeOptions :: PagesizeLimit -- ^ Current/previous value
+                -> NonNull [PagesizeLimit]
+pagesizeOptions psLim = impureNonNull . Set.toAscList . Set.fromList $ psLim : PagesizeAll : map PagesizeLimit opts
+  where
+    opts :: [Int64]
+    opts = filter (> 0) $ opts' <> map (`div` 2) opts'
+
+    opts' = [ 10^n | n <- [1..3]]
+
 pagesizeField :: PagesizeLimit -> Field Handler PagesizeLimit
 pagesizeField psLim = selectField $ do
   MsgRenderer mr <- getMsgRenderer
@@ -767,16 +776,9 @@ pagesizeField psLim = selectField $ do
     optText (PagesizeLimit l) = tshow l
     optText PagesizeAll = mr MsgDBTablePagesizeAll
 
-    toOptionList = flip OptionList fromPathPiece . map (\o -> Option (optText o) o $ toPathPiece o) . Set.toAscList . Set.fromList
-  return $ toOptionList limOpts
-  where
-    limOpts :: [PagesizeLimit]
-    limOpts = psLim : PagesizeAll : map PagesizeLimit opts
+    toOptionList = flip OptionList fromPathPiece . map (\o -> Option (optText o) o $ toPathPiece o)
+  return . toOptionList . toNullable $ pagesizeOptions psLim
 
-    opts :: [Int64]
-    opts = filter (> 0) $ opts' <> map (`div` 2) opts'
-
-    opts' = [ 10^n | n <- [1..3]]
 
 --- DBCell utility functions
 

templates/table/layout.hamlet

@@ -7,8 +7,8 @@ $else
   <div .table-footer>
     <div .table__row-count>
       _{MsgRowCount rowCount}
-    <!-- TODO: replace '5' with 'minPagesize' -->
-    $if rowCount > 5
+    $# Since the current pagesize is always a member of pagesizeOptions we don't need to check `pageCount > 1`
+    $if toEnum (fromIntegral rowCount) > minimum (pagesizeOptions referencePagesize)
       <form .pagesize method=GET enctype=#{pagesizeEnc} action=#{rawAction}>
         ^{pagesizeWdgt}