From 8107dab6f7e770e78000bc65a3339bc3d900c264 Mon Sep 17 00:00:00 2001
From: Andreas Deininger <adeininger@urbanonline.de>
Date: Thu, 20 Oct 2022 18:12:03 +0200
Subject: [PATCH] mermaid diagrams: automatic activation (with hugo >=0.93.0)

---
 assets/js/mermaid.js                            | 17 ++++++++++++++---
 .../_markup/render-codeblock-mermaid.html       |  2 ++
 layouts/partials/scripts.html                   |  9 +++++++--
 userguide/config.yaml                           |  3 ---
 4 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/assets/js/mermaid.js b/assets/js/mermaid.js
index 9580739917..90d162ebab 100644
--- a/assets/js/mermaid.js
+++ b/assets/js/mermaid.js
@@ -1,10 +1,22 @@
-{{ with .Site.Params.mermaid }}
-{{ if .enable }}
+{{ $needmermaid := or .Site.Params.mermaid.enable -}}
+{{ if ge hugo.Version "0.93.0" -}}
+    {{ $needmermaid = or $needmermaid (.Page.Store.Get "hasmermaid") -}}
+{{ end }}
+
+{{ if $needmermaid }}
 (function($) {
     var needMermaid = false;
+
+{{ if ge hugo.Version "0.93.0" -}}
     if ($('.mermaid').length > 0) {
         needMermaid = true;
     };
+{{ else -}}
+    $('.language-mermaid').parent().replaceWith(function() {
+        needMermaid = true;
+        return $('<pre class="mermaid">').text($(this).text());
+    });
+{{ end -}}
 
     if (!needMermaid)  {
         mermaid.initialize({startOnLoad: false});
@@ -34,4 +46,3 @@
     mermaid.initialize(settings);
 })(jQuery);
 {{ end }}
-{{ end }}
diff --git a/layouts/_default/_markup/render-codeblock-mermaid.html b/layouts/_default/_markup/render-codeblock-mermaid.html
index 85166b1de9..0b8d7c01bd 100644
--- a/layouts/_default/_markup/render-codeblock-mermaid.html
+++ b/layouts/_default/_markup/render-codeblock-mermaid.html
@@ -1,3 +1,5 @@
+{{ .Page.Store.Set "hasmermaid" true -}}
+
 <div class="mermaid">
   {{- .Inner | safeHTML }}
 </div>
diff --git a/layouts/partials/scripts.html b/layouts/partials/scripts.html
index 9cc401bbbb..b47d8ba7c4 100644
--- a/layouts/partials/scripts.html
+++ b/layouts/partials/scripts.html
@@ -1,5 +1,10 @@
-{{ if .Site.Params.mermaid.enable -}}
-  <script src="https://cdn.jsdelivr.net/npm/mermaid@9.1.3/dist/mermaid.min.js" integrity="sha512-E/owfVh8/U1xwhvIT4HSI064DRc1Eo/xf7AYax84rt9gVqA8tc/JNH/lvTl1tuw9PUHQIMGUtObkjYkgRjFqAA==" crossorigin="anonymous"></script>
+{{ $needmermaid := or .Site.Params.mermaid.enable -}}
+{{ if ge hugo.Version "0.93.0" -}}
+    {{ $needmermaid = or $needmermaid (.Page.Store.Get "hasmermaid") -}}
+{{ end }}
+
+{{ if $needmermaid -}}
+  <script src="https://cdn.jsdelivr.net/npm/mermaid@9.1.7/dist/mermaid.min.js" integrity="sha512-1ypa9tdUrJAWv5g28Mb5x0zXaUuI4SBofKff88OGyk5D/oOd4x1IPxYHsx3K81bwBKt8NVUvGgw7TgNZ6PJX2A==" crossorigin="anonymous"></script>
 {{ end -}}
 
 {{ if .Site.Params.markmap.enable -}}
diff --git a/userguide/config.yaml b/userguide/config.yaml
index dd3ba61bca..483d2bfd3c 100644
--- a/userguide/config.yaml
+++ b/userguide/config.yaml
@@ -106,9 +106,6 @@ params:
         icon: fa-brands fa-github
         desc: Development takes place here!
 
-  mermaid:
-    enable: true
-    theme: default
   plantuml:
     enable: true
     theme: default