From f3edcc1752c231312f7ee05b430f7010e983ef72 Mon Sep 17 00:00:00 2001
From: Jake Howard <git@theorangeone.net>
Date: Sun, 24 Sep 2023 18:04:13 +0100
Subject: [PATCH] Mutate external URLs

---
 content/index.md     |  6 +++++-
 hooks/url-rewrite.py | 23 +++++++++++++++++++++++
 mkdocs.yml           |  5 +++++
 3 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 hooks/url-rewrite.py

diff --git a/content/index.md b/content/index.md
index 60a81c5..dc160a6 100644
--- a/content/index.md
+++ b/content/index.md
@@ -8,4 +8,8 @@ After image
 
 ![Image](https://theorangeone.net/images/ml7eDl0dfJcNa0gb78bceOAZA2Y=/1/width-1200/header.jpg)
 
-{{ 1 + 2}}
+{{ 1 + 2 }}
+
+- [Another page](./other.md)
+- [Something else on the site](/sitemap.xml)
+- [An external site](https://mkdocs.org)
diff --git a/hooks/url-rewrite.py b/hooks/url-rewrite.py
new file mode 100644
index 0000000..a6fabb7
--- /dev/null
+++ b/hooks/url-rewrite.py
@@ -0,0 +1,23 @@
+from bs4 import BeautifulSoup
+from urllib.parse import urlsplit, urlunsplit, parse_qs, urlencode
+
+
+def on_page_content(html, page, config, files):
+    soup = BeautifulSoup(html, "html.parser")
+
+    for link in soup.find_all("a", href=True):
+        parsed_url = urlsplit(link["href"])
+
+        if not parsed_url.scheme or not parsed_url.netloc:
+            # Not an external link
+            continue
+
+        # Stick a reference on external URLs
+        parsed_url = parsed_url._replace(query=urlencode({
+            **parse_qs(parsed_url.query),
+            "ref": "mysite.com"
+        }))
+
+        link["href"] = urlunsplit(parsed_url)
+
+    return str(soup)
diff --git a/mkdocs.yml b/mkdocs.yml
index a6e0ab3..a6c0d79 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -21,6 +21,7 @@ hooks:
   - hooks/include-file.py
   - hooks/unsplash.py
   - hooks/exclude-static.py
+  - hooks/url-rewrite.py
 
 markdown_extensions:
   - attr_list
@@ -29,3 +30,7 @@ markdown_extensions:
 
 plugins:
   - search
+
+validation:
+  links:
+    absolute_links: ignore