web: register page: clip linked accounts to 40 characters

This was the behaviour before adding the links.

hledger-web/Hledger/Web/Handler/RegisterR.hs

@@ -34,8 +34,13 @@ getRegisterR = do
       acctQuery = fromMaybe Any (inAccountQuery qopts)
       acctlink acc = (RegisterR, [("q", accountQuery acc)])
       otherTransAccounts =
+          map (\(acct,(name,comma)) -> (acct, (T.pack name, T.pack comma))) .
+          undecorateLinks . elideRightDecorated 40 . decorateLinks .
           addCommas . preferReal . otherTransactionAccounts m acctQuery
-      addCommas xs = zip xs $ tail $ (","<$xs) ++ [T.empty]
+      addCommas xs =
+          zip xs $
+          zip (map (T.unpack . accountSummarisedName . paccount) xs) $
+          tail $ (", "<$xs) ++ [""]
       r@(balancelabel,items) = accountTransactionsReport ropts j m acctQuery
       balancelabel' = if isJust (inAccount qopts) then balancelabel else "Total"
   defaultLayout $ do
@@ -63,6 +68,28 @@ preferReal ps
     | otherwise   = realps
     where realps = filter isReal ps
 
+elideRightDecorated :: Int -> [(Maybe d, Char)] -> [(Maybe d, Char)]
+elideRightDecorated width s =
+    if length s > width
+        then take (width - 2) s ++ map ((,) Nothing) ".."
+        else s
+
+undecorateLinks :: [(Maybe acct, char)] -> [(acct, ([char], [char]))]
+undecorateLinks [] = []
+undecorateLinks xs0@(x:_) =
+    case x of
+        (Just acct, _) ->
+            let (link, xs1) = span (isJust . fst) xs0
+                (comma, xs2) = span (isNothing . fst) xs1
+            in (acct, (map snd link, map snd comma)) : undecorateLinks xs2
+        _ -> error "link name not decorated with account"
+
+decorateLinks :: [(acct, ([char], [char]))] -> [(Maybe acct, char)]
+decorateLinks =
+    concatMap
+        (\(acct, (name, comma)) ->
+            map ((,) (Just acct)) name ++ map ((,) Nothing) comma)
+
 -- | Generate javascript/html for a register balance line chart based on
 -- the provided "TransactionsReportItem"s.
 registerChartHtml :: [(CommoditySymbol, (String, [TransactionsReportItem]))] -> HtmlUrl AppRoute

hledger-web/templates/register.hamlet

@@ -26,9 +26,9 @@
           <td>
             #{textElideRight 30 (tdescription tacct)}
           <td .account>
-            $forall (Posting { paccount = acc }, comma) <- otherTransAccounts torig
+            $forall (Posting { paccount = acc }, (summName,comma)) <- otherTransAccounts torig
               <a href="@?{acctlink acc}##{tindex torig}" title="#{acc}">
-                #{accountSummarisedName acc}</a>#{comma}
+                #{summName}</a>#{comma}
           <td .amount style="text-align:right; white-space:nowrap;">
             $if not split || not (isZeroMixedAmount amt)
               ^{mixedAmountAsHtml amt}