avoid overwriting timestamps if they are forced by markdown already

1 files changed, 11 insertions, 9 deletions

diff --git a/site.hs b/site.hs
index 7989dff..d60486e 100644
--- a/site.hs
+++ b/site.hs
@@ -182,15 +182,17 @@ timestampFile fp = do
 
 -- | If a timestamp file for the page exists, add the timestamp metadata.
 addTimeMeta :: PageInfo -> Y.Value -> Site Y.Value
-addTimeMeta pi m'@(Y.Object m) = do
-  tspath <- timestampFile $ pi ^. pagePath
-  io $
-    ifM
-      (doesFileExist tspath)
-      (do putStrLn $ "timestamp <- " ++ tspath
-          ts <- Y.String <$> TIO.readFile tspath
-          pure . Y.Object $ KM.insert "timestamp" ts m)
-      (pure m')
+addTimeMeta pi m'@(Y.Object m)
+  | "timestamp" `KM.member` m = pure m' -- do not overwrite the timestamp if present
+  | otherwise = do
+    tspath <- timestampFile $ pi ^. pagePath
+    io $
+      ifM
+        (doesFileExist tspath)
+        (do putStrLn $ "timestamp <- " ++ tspath
+            ts <- Y.String <$> TIO.readFile tspath
+            pure . Y.Object $ KM.insert "timestamp" ts m)
+        (pure m')
 
 -- | Add page-specific information to the metadata. In this instance, this just
 -- expands the tags for rendering. Eventually would be nice to have the timestamps