From 8583520baf01323c9de87514ca240bdbe09da80a Mon Sep 17 00:00:00 2001
From: Mylloon <kennel.anri@tutanota.com>
Date: Sun, 31 Mar 2024 18:05:31 +0200
Subject: [PATCH] fix math integration

---
 src/misc/markdown.rs    | 24 +++++++++++++++++++++---
 static/js/libs/katex.js | 18 +++++++++---------
 2 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/src/misc/markdown.rs b/src/misc/markdown.rs
index e02916a..7e3228a 100644
--- a/src/misc/markdown.rs
+++ b/src/misc/markdown.rs
@@ -1,10 +1,12 @@
 use crate::misc::date::Date;
 use comrak::nodes::{AstNode, NodeValue};
 use comrak::{format_html, parse_document, Arena, ComrakOptions, ListStyleType};
-use lol_html::{element, rewrite_str, RewriteStrSettings};
+use lol_html::{element, rewrite_str, HtmlRewriter, RewriteStrSettings, Settings};
 use ramhorns::Content;
 use serde::{Deserialize, Deserializer};
 use std::fs;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
 
 /// Metadata for blog posts
 #[derive(Content, Debug, Default, Deserialize)]
@@ -322,9 +324,25 @@ fn check_code<'a>(root: &'a AstNode<'a>, blacklist: &[String]) -> bool {
     })
 }
 
-/// Check if html can contains maths
+/// Check if html contains maths
 fn check_math(html: &str) -> bool {
-    html.contains('$')
+    let math_detected = Arc::new(AtomicBool::new(false));
+
+    let mut output = vec![];
+    let _ = HtmlRewriter::new(
+        Settings {
+            element_content_handlers: vec![element!("span[data-math-style]", |_| {
+                math_detected.store(true, Ordering::SeqCst);
+
+                Ok(())
+            })],
+            ..Settings::default()
+        },
+        |c: &[u8]| output.extend_from_slice(c),
+    )
+    .write(html.as_bytes());
+
+    math_detected.load(Ordering::SeqCst)
 }
 
 /// Change class of languages for hljs detection
diff --git a/static/js/libs/katex.js b/static/js/libs/katex.js
index 8c06455..bb220db 100644
--- a/static/js/libs/katex.js
+++ b/static/js/libs/katex.js
@@ -16,13 +16,13 @@ window.addEventListener("load", () => {
     macros[`\\${item[0]}`] = `\\${item[1]}`;
   }
 
-  renderMathInElement(document.body, {
-    delimiters: [
-      { left: "$$", right: "$$", display: true },
-      { left: "$", right: "$", display: false },
-    ],
-    throwOnError: false,
-    macros,
-    output: "mathml",
-  });
+  const attribute = "data-math-style";
+  for (let element of document.querySelectorAll(`span[${attribute}]`)) {
+    katex.render(element.textContent, element, {
+      throwOnError: false,
+      displayMode: element.getAttribute(attribute) === "display",
+      macros,
+      output: "mathml",
+    });
+  }
 });