Fixed image previews just in time to not want Hakyll anymore

site.hs

@@ -52,13 +52,15 @@ options = Options { verbosity = True
                                        }
                   }
 
+reducedExtn :: FilePath -> FilePath
+reducedExtn x = replaceExtension x (".reduced" ++ takeExtension x)
+
 -- | Main entry point for generating all code via Hakyll
 main :: IO ()
 main = do
   E.setLocaleEncoding E.utf8
   hakyll $ do
-  --hakyllWithArgs config options $ do
-    -- Build up tags
+  --hakyllWithArgs config options $ do tags
     tags <- buildTags "posts/*" (fromCapture "tags/*.html")
     let postCtxTags = postCtxWithTags tags
 
@@ -67,12 +69,13 @@ main = do
         route   idRoute
         compile copyFileCompiler
 
-    -- But also, make 640x480 reduced versions with /thumbnail
-    -- prepended to their path:
-    match ("images/**.jpg" .||. "images/**.png") $ version "thumbnail" $ do
-        route $ customRoute $ combine "./thumbnail/" . toFilePath
+    -- But also, make reduced versions with (e.g.) that replace
+    -- "foo.jpg" with ".reduced.jpg":
+    match ("images/**.jpg" .||. "images/**.png") $ version "reduced" $ do
+        --route $ customRoute $ combine "./thumbnail/" . toFilePath
+        route $ customRoute $ reducedExtn . toFilePath
         compile $ loadImage
-            >>= scaleImageCompiler 640 480
+            >>= scaleImageCompiler 500 500
 
     -- (I don't fully understand what role "version" plays here except
     -- that it appears to be required for me to have two matches on
@@ -161,8 +164,16 @@ main = do
         route idRoute
         compile $ do
             posts <- recentFirst =<< loadAllSnapshots "works/*" "content"
+            let getExtn x = do
+                  s <- getMetadataField' (itemIdentifier x) "img"
+                  return $ reducedExtn s
+                  -- TODO: Can't I make this a simpler (well... maybe)
+                  -- one-liner?
+            let ctxt2 = postCtxTags `mappend` (field "imgpreview" getExtn)
+            -- Why does this work?  I guess imgpreview needs to be
+            -- inside the listField (given how I use it).
             let archiveCtx = 
-                    listField "works" postCtxTags (return posts) `mappend`
+                    listField "works" ctxt2 (return posts) `mappend`
                     constField "title" "Something"               `mappend`
                     defaultContext
             makeItem ""

templates/post-grid.html

@@ -4,7 +4,7 @@
   <div class="col-sm-6">
     <h3>$title$</h3>
     <a href="$img$">
-      <img src="$img$" class="img-responsive"/>
+      <img src="$imgpreview$" class="img-responsive"/>
     </a>
     <!-- N.B. use img-fluid for Bootstrap 4 -->
     $if(description)$