From 5b265833f5ce549dac4e73ae25997105b38a75bc Mon Sep 17 00:00:00 2001
From: Stephan Lachnit <stephanlachnit@debian.org>
Date: Tue, 26 Apr 2022 17:01:07 +0200
Subject: [PATCH] performance: use hugo render hook for Mermaid

This switches Mermaid to use hugo's Markdown
render hooks [1] instead of manipulating the string at runtime, which
should improve performance by a bit.

[1]: https://gohugo.io/templates/render-hooks/#render-hooks-for-code-blocks

Signed-off-by: Stephan Lachnit <stephanlachnit@debian.org>
---
 assets/js/mermaid.js                                   | 5 ++---
 layouts/_default/_markup/render-codeblock-mermaid.html | 3 +++
 2 files changed, 5 insertions(+), 3 deletions(-)
 create mode 100644 layouts/_default/_markup/render-codeblock-mermaid.html

diff --git a/assets/js/mermaid.js b/assets/js/mermaid.js
index 821e567872..9580739917 100644
--- a/assets/js/mermaid.js
+++ b/assets/js/mermaid.js
@@ -2,10 +2,9 @@
 {{ if .enable }}
 (function($) {
     var needMermaid = false;
-    $('.language-mermaid').parent().replaceWith(function() {
+    if ($('.mermaid').length > 0) {
         needMermaid = true;
-        return $('<pre class="mermaid">').text($(this).text());
-    });
+    };
 
     if (!needMermaid)  {
         mermaid.initialize({startOnLoad: false});
diff --git a/layouts/_default/_markup/render-codeblock-mermaid.html b/layouts/_default/_markup/render-codeblock-mermaid.html
new file mode 100644
index 0000000000..85166b1de9
--- /dev/null
+++ b/layouts/_default/_markup/render-codeblock-mermaid.html
@@ -0,0 +1,3 @@
+<div class="mermaid">
+  {{- .Inner | safeHTML }}
+</div>