renderNotFound uses the same approach as normal 404 errors in IHP now. …

…Fixes #1180

renderNotFound now renders the normal not found page. It also respects the static/404.html if such a file exists.

IHP/Controller/Render.hs

@@ -20,6 +20,7 @@ import IHP.Controller.Layout
 import qualified IHP.FrameworkConfig as FrameworkConfig
 import qualified Data.ByteString.Builder as ByteString
 import IHP.FlashMessages.ControllerFunctions (initFlashMessages)
+import qualified IHP.ErrorController as ErrorController
 
 renderPlain :: (?context :: ControllerContext) => LByteString -> IO ()
 renderPlain text = respondAndExit $ responseLBS status200 [(hContentType, "text/plain")] text
@@ -89,9 +90,19 @@ renderJson' :: (?context :: ControllerContext) => ResponseHeaders -> Data.Aeson.
 renderJson' additionalHeaders json = respondAndExit $ responseLBS status200 ([(hContentType, "application/json")] <> additionalHeaders) (Data.Aeson.encode json)
 {-# INLINABLE renderJson' #-}
 
+-- | Render's a generic not found page
+--
+-- This can be useful e.g. when an entity cannot be found:
+--
+-- > action ExampleAction = do
+-- >     renderNotFound
+--
+-- You can override the default not found error page by creating a new file at @static/404.html@. Then IHP will render that HTML file instead of displaying the default IHP not found page.
+--
 renderNotFound :: (?context :: ControllerContext) => IO ()
-renderNotFound = renderPlain "Not Found"
-{-# INLINABLE renderNotFound #-}
+renderNotFound = do
+    response <- ErrorController.buildNotFoundResponse
+    respondAndExit response
 
 data PolymorphicRender
     = PolymorphicRender

IHP/ErrorController.hs

@@ -8,6 +8,7 @@ module IHP.ErrorController
 , handleNoResponseReturned
 , handleNotFound
 , handleRouterException
+, buildNotFoundResponse
 ) where
 
 import IHP.Prelude hiding (displayException)
@@ -55,16 +56,19 @@ handleNoResponseReturned controller = do
 -- | Renders a 404 not found response. If a static/404.html exists, that is rendered instead of the IHP not found page
 handleNotFound :: (?context :: RequestContext) => IO ResponseReceived
 handleNotFound = do
-    hasCustomNotFound <- Directory.doesFileExist "static/404.html"
-    response <- if hasCustomNotFound
-            then customNotFoundResponse
-            else pure defaultNotFoundResponse
-
+    response <- buildNotFoundResponse
     let RequestContext { respond } = ?context
     respond response
 
+buildNotFoundResponse :: forall context. (?context :: context, ConfigProvider context) => IO Response
+buildNotFoundResponse = do
+    hasCustomNotFound <- Directory.doesFileExist "static/404.html"
+    if hasCustomNotFound
+        then customNotFoundResponse
+        else pure defaultNotFoundResponse
+
 -- | The default IHP 404 not found page
-defaultNotFoundResponse :: (?context :: RequestContext) => Response
+defaultNotFoundResponse :: forall context. (?context :: context, ConfigProvider context) => Response
 defaultNotFoundResponse = do
     let errorMessage = [hsx|Router failed to find an action to handle this request.|]
     let title = H.text "Action Not Found"