From 4d36f4f1e363cfc9005b7d0ff1eb544b72559bba Mon Sep 17 00:00:00 2001
From: Jake Howard <git@theorangeone.net>
Date: Sun, 17 Sep 2023 20:13:45 +0100
Subject: [PATCH] Allow escaping markdown from external data

---
 content/nested/sibling.md |  4 ++--
 hooks/unsplash.py         | 12 ++++++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/content/nested/sibling.md b/content/nested/sibling.md
index bd80784..b4ca089 100644
--- a/content/nested/sibling.md
+++ b/content/nested/sibling.md
@@ -5,6 +5,6 @@ redirects:
 
 # Sibling
 
-{% set this_image = unsplash("MU8w72PzRow") %}
+{% set this_image = unsplash("yCdPU73kGSc") %}
 
-![{{ this_image.description|default("", true) }}]({{ this_image.urls.regular }})
+![{{ this_image.description|default("", true)|escape_markdown }}]({{ this_image.urls.regular }})
diff --git a/hooks/unsplash.py b/hooks/unsplash.py
index ff6dfa7..edd27cc 100644
--- a/hooks/unsplash.py
+++ b/hooks/unsplash.py
@@ -3,14 +3,26 @@ from datetime import timedelta
 import os
 import json
 import jinja2
+import re
 
 UNSPLASH_CACHE_TIME = timedelta(days=14)
 
+MD_ESCAPE_CHARS = r"\_*[]()~`>#+-=|{}.!"
+MD_ESCAPE_RE = re.compile(f"([{re.escape(MD_ESCAPE_CHARS)}])")
+
 def get_unsplash_image(image_id):
     client_id = os.environ["UNSPLASH_CLIENT_ID"]
     url = f"https://api.unsplash.com/photos/{image_id}?client_id={client_id}"
     return json.loads(download_and_cache_url(url, UNSPLASH_CACHE_TIME))
 
+
+def escape_markdown(value):
+    return MD_ESCAPE_RE.sub(r"\\\1", value)
+
+
 def on_env(env: jinja2.Environment, config, files):
     env.globals["unsplash"] = get_unsplash_image
+
+    env.filters["escape_markdown"] = escape_markdown
+
     return env