From 05fde1f464c3632175fb726b358b48ce578e7a96 Mon Sep 17 00:00:00 2001
From: Michael Snoyman <michael@snoyman.com>
Date: Mon, 20 Dec 2010 19:00:30 +0200
Subject: [PATCH] getBy404

---
 Yesod/Yesod.hs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Yesod/Yesod.hs b/Yesod/Yesod.hs
index 74288fa3..1523f7d4 100644
--- a/Yesod/Yesod.hs
+++ b/Yesod/Yesod.hs
@@ -15,6 +15,7 @@ module Yesod.Yesod
     , YesodPersist (..)
     , module Database.Persist
     , get404
+    , getBy404
       -- ** Breadcrumbs
     , YesodBreadcrumbs (..)
     , breadcrumbs
@@ -392,6 +393,15 @@ get404 key = do
         Nothing -> lift notFound
         Just res -> return res
 
+getBy404 :: (PersistBackend (t m), PersistEntity val, Monad (t m),
+             Failure ErrorResponse m, MonadTrans t)
+         => Unique val -> t m (Key val, val)
+getBy404 ukey = do
+  mres <- getBy ukey
+  case mres of
+    Nothing -> lift notFound
+    Just res -> return res
+
 -- | Return the same URL if the user is authorized to see it.
 --
 -- Built on top of 'isAuthorized'. This is useful for building page that only