1 files changed, 95 insertions, 0 deletions
diff --git a/web/blog/fragments.nix b/web/blog/fragments.nix
new file mode 100644
index 000000000000..63fc1ab4c5cf
--- /dev/null
+++ b/web/blog/fragments.nix
@@ -0,0 +1,95 @@
+# This file defines various fragments of the blog, such as the header
+# and footer, as functions that receive arguments to be templated into
+# them.
+#
+# An entire post is rendered by `renderPost`, which assembles the
+# fragments together in a runCommand execution.
+{ depot, lib, pkgs, ... }:
+
+let
+  inherit (builtins) filter map hasAttr replaceStrings;
+  inherit (pkgs) runCommandNoCC writeText;
+  inherit (depot.nix) renderMarkdown;
+
+  staticUrl = "https://static.tvl.fyi/${depot.web.static.drvHash}";
+
+  # Generate a post list for all listed, non-draft posts.
+  isDraft = post: (hasAttr "draft" post) && post.draft;
+  isUnlisted = post: (hasAttr "listed" post) && !post.listed;
+
+  escape = replaceStrings [ "<" ">" "&" "'" ] [ "&lt;" "&gt;" "&amp;" "&#39;" ];
+
+  header = name: title: ''
+  <!DOCTYPE html>
+  <head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <meta name="description" content="${escape name}">
+    <link rel="stylesheet" type="text/css" href="${staticUrl}/tvl.css" media="all">
+    <link rel="icon" type="image/webp" href="/static/favicon.webp">
+    <link rel="alternate" type="application/atom+xml" title="Atom Feed" href="https://tvl.fyi/feed.atom">
+    <title>${escape name}: ${escape title}</title>
+  </head>
+  <body class="light">
+    <header>
+      <h1><a class="blog-title" href="/">${escape name}</a> </h1>
+      <hr>
+    </header>
+  '';
+
+  fullFooter = content: ''
+    <hr>
+    <footer>
+      ${content}
+    </footer>
+  </body>
+  '';
+
+  draftWarning = writeText "draft.html" ''
+    <p class="cheddar-callout cheddar-warning">
+      <b>Note:</b> This post is a <b>draft</b>! Please do not share
+      the link to it without asking first.
+    </p>
+    <hr>
+  '';
+
+  unlistedWarning = writeText "unlisted.html" ''
+    <p class="cheddar-callout cheddar-warning">
+      <b>Note:</b> This post is <b>unlisted</b>! Please do not share
+      the link to it without asking first.
+    </p>
+    <hr>
+  '';
+
+  renderPost = { name, footer, ... }: post: runCommandNoCC "${post.key}.html" {} ''
+    cat ${writeText "header.html" (header name post.title)} > $out
+
+    # Write the post title & date
+    echo '<article><h2 class="inline">${escape post.title}</h2>' >> $out
+    echo '<aside class="date">' >> $out
+    date --date="@${toString post.date}" '+%Y-%m-%d' >> $out
+    ${
+      if post ? updated
+      then ''date --date="@${toString post.updated}" '+ (updated %Y-%m-%d)' >> $out''
+      else ""
+    }
+    echo '</aside>' >> $out
+
+    ${
+      # Add a warning to draft/unlisted posts to make it clear that
+      # people should not share the post.
+
+      if (isDraft post) then "cat ${draftWarning} >> $out"
+      else if (isUnlisted post) then "cat ${unlistedWarning} >> $out"
+      else "# Your ads could be here?"
+    }
+
+    # Write the actual post through cheddar's about-filter mechanism
+    cat ${renderMarkdown post.content} >> $out
+    echo '</article>' >> $out
+
+    cat ${writeText "footer.html" (fullFooter footer)} >> $out
+  '';
+in {
+  inherit isDraft isUnlisted renderPost;
+}