From eb676545687f41825dda4bd4fa8212332c094dec Mon Sep 17 00:00:00 2001
From: Dhananjay Balan <mail@dbalan.in>
Date: Mon, 28 Jan 2019 16:42:01 -0500
Subject: [PATCH] Implement Tags!

---
 site.hs             | 24 +++++++++++++++++++++---
 templates/post.html | 12 ++++++------
 2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/site.hs b/site.hs
index 563b4e8..21b70ba 100644
--- a/site.hs
+++ b/site.hs
@@ -34,7 +34,7 @@ feedConfig = FeedConfiguration {
 
 main :: IO ()
 main = hakyllWith config $ do
-    tags <- extractTags
+    tags <- buildTags "blog/*" (fromCapture "tags/*.html")
 
     match "images/*" $ do
         route   idRoute
@@ -59,9 +59,9 @@ main = hakyllWith config $ do
     match "blog/*" $ do
         route $  octopressRoute
         compile $ pandocCompiler
-            >>= loadAndApplyTemplate "templates/post.html"    postCtx
+            >>= loadAndApplyTemplate "templates/post.html"    (postCtxWTags tags)
             >>= saveSnapshot "content"
-            >>= loadAndApplyTemplate "templates/default.html" postCtx
+            >>= loadAndApplyTemplate "templates/default.html" (postCtxWTags tags)
             >>= relativizeUrls
 
     match "index.html" $ do
@@ -93,6 +93,21 @@ main = hakyllWith config $ do
                 >>= loadAndApplyTemplate "templates/default.html" archiveCtx
                 >>= relativizeUrls
 
+    -- tags!
+    tagsRules tags $ \tag pattern -> do
+        let title = "Posts tagged \"" ++ tag ++ "\""
+        route idRoute
+        compile $ do
+            posts <- recentFirst =<< loadAll pattern
+            let ctx = constField "title" title
+                      `mappend` listField "posts" postCtx (return posts)
+                      `mappend` defaultContext
+
+            makeItem ""
+                >>= loadAndApplyTemplate "templates/tag.html" ctx
+                >>= loadAndApplyTemplate "templates/default.html" ctx
+                >>= relativizeUrls
+
     create ["atom.xml"] $ do
       route idRoute
       compile $ do
@@ -107,6 +122,9 @@ extractTags = do
   tags <- buildTags ("blogs/**" .&&. hasNoVersion) $ fromCapture "tags/*.html"
   return $ sortTagsBy caseInsensitiveTags tags
 
+postCtxWTags :: Tags -> Context String
+postCtxWTags tags = tagsField "tags" tags <> postCtx
+
 postCtx :: Context String
 postCtx =
     dateField "date" "%B %e, %Y" `mappend`
diff --git a/templates/post.html b/templates/post.html
index 7336351..ac0d2ce 100644
--- a/templates/post.html
+++ b/templates/post.html
@@ -1,12 +1,12 @@
 <article class="group">
     <h1>$title$</h1>
-    <p class="subtitle">$date$</p>
+    <p class="subtitle">$date$
+    $if(tags)$
+    , posted in $tags$
+    $endif$
+    </p>
+
     <section>
         $body$
     </section>
-    <section>
-        $if(tags)$
-        <br>Posted in <i>$tags$</i>
-        $endif$
-    </section>
 </article>