From cfba9572c289d6c612c696d1e441ec93a94f9499 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9o=20Winterhalter?= <theo.winterhalter@gmail.com>
Date: Thu, 7 Nov 2024 15:52:31 +0100
Subject: [PATCH] Add last updated date

---
 .github/workflows/webpage.yaml |  1 +
 Makefile                       |  1 +
 README.md                      | 14 ++++++++++++++
 pandoc/date.lua                |  6 ++++++
 pandoc/template.html4          |  2 ++
 src/index.md                   |  5 ++++-
 website/style.css              |  4 ++++
 7 files changed, 32 insertions(+), 1 deletion(-)
 create mode 100644 pandoc/date.lua

diff --git a/.github/workflows/webpage.yaml b/.github/workflows/webpage.yaml
index a2869f5..660a42d 100644
--- a/.github/workflows/webpage.yaml
+++ b/.github/workflows/webpage.yaml
@@ -39,6 +39,7 @@ jobs:
             --toc-depth=1
             --resource-path=.
             --lua-filter=pandoc/paper.lua
+            --lua-filter=pandoc/date.lua
             src/index.md
 
       - name: Setup Pages
diff --git a/Makefile b/Makefile
index 0bddd10..5765127 100644
--- a/Makefile
+++ b/Makefile
@@ -10,4 +10,5 @@ website:
          --toc-depth=1 \
          --resource-path=. \
          --lua-filter=pandoc/paper.lua \
+         --lua-filter=pandoc/date.lua \
          src/index.md
diff --git a/README.md b/README.md
index bc92b6e..367cc3d 100644
--- a/README.md
+++ b/README.md
@@ -197,6 +197,20 @@ assume them to be empty otherwise), while the other fields (`venue`, `year`,
     * `link`
     * `git`
 
+## Updating the HTML template
+
+The `pandoc/template.html4` file contains an HTML template which you can edit
+to suit your taste. Any variable mentioned in the header of your `index.md` can
+be moved around, and you can even add your own.
+
+There is also a special filter called `pandoc/date.lua` which produces an extra
+variable called `date` (unless it is already provided in the header) that is
+currently used in the footer of the template to indicate the last time the page
+was generated.
+
+> [!NOTE]
+> It will only appear in the footer if the `footer` variable is set.
+
 ## Sharing files
 
 Anything you put in the `website` directory will be available online too.
diff --git a/pandoc/date.lua b/pandoc/date.lua
new file mode 100644
index 0000000..14da312
--- /dev/null
+++ b/pandoc/date.lua
@@ -0,0 +1,6 @@
+function Meta(m)
+  if m.date == nil then
+    m.date = os.date("%e %B %Y")
+    return m
+  end
+end
diff --git a/pandoc/template.html4 b/pandoc/template.html4
index 8a9ca23..8e09160 100644
--- a/pandoc/template.html4
+++ b/pandoc/template.html4
@@ -159,6 +159,8 @@
   $if(footer)$
   <footer>
     $footer$
+
+    <span class="lastupdate">Last updated: $date$</span>
   </footer>
   $endif$
 </body>
diff --git a/src/index.md b/src/index.md
index c412c28..67a2a7d 100644
--- a/src/index.md
+++ b/src/index.md
@@ -21,7 +21,10 @@ gitlab: gitlab
 bitbucket: bitbucket.com
 bluesky: https://bsky.app/
 linkedin: https://www.linkedin.com
-footer: Based on the [basicpage template](https://github.com/basicpage/basicpage.github.io), made to be easy to use! 🎓
+footer: >-
+  Based on the
+  [basicpage template](https://github.com/basicpage/basicpage.github.io),
+  made to be easy to use! 🎓
 ---
 
 I am a (fake) PhD student, working on 👽 science on all kinds of related topics.
diff --git a/website/style.css b/website/style.css
index 1a6d57d..31ecb43 100644
--- a/website/style.css
+++ b/website/style.css
@@ -335,6 +335,10 @@ div.files a:hover {
   text-decoration: none;
 }
 
+span.lastupdate {
+  color: #9e9d9d;
+}
+
 @media screen and (min-width: 1000px) {
   header.split {
     flex-direction: row;