snapshot of https://github.com/go-gitea/gitea.git (main, 2026-09-15; blobs > 131072B omitted)

web_src/js/markup/math.ts

@@ -0,0 +1,48 @@
+import {displayError} from './common.ts';
+import {queryElems} from '../utils/dom.ts';
+
+function targetElement(elCode: Element): {target: Element, displayAsBlock: boolean} {
+  // The target element is either the parent "code block with loading indicator", or itself
+  // It is designed to work for 2 cases (guaranteed by backend code):
+  // * <pre class="code-block"><code class="language-math">...</code></pre>
+  // * <code class="language-math">...</code>
+  const elPre = elCode.parentElement?.matches('pre.code-block') ? elCode.parentElement : null;
+  return {
+    target: elPre ?? elCode,
+    displayAsBlock: elPre !== null,
+  };
+}
+
+export async function initMarkupCodeMath(elMarkup: HTMLElement): Promise<void> {
+  // .markup code.language-math'
+  queryElems(elMarkup, 'code.language-math', async (el) => {
+    const [{default: katex}] = await Promise.all([
+      import('katex'),
+      import('katex/dist/katex.css'),
+    ]);
+
+    const MAX_CHARS = 1000;
+    const MAX_SIZE = 25;
+    const MAX_EXPAND = 1000;
+
+    const {target, displayAsBlock} = targetElement(el);
+    if (target.hasAttribute('data-render-done')) return;
+    const source = el.textContent;
+
+    if (source.length > MAX_CHARS) {
+      displayError(target, new Error(`Math source of ${source.length} characters exceeds the maximum allowed length of ${MAX_CHARS}.`));
+      return;
+    }
+    try {
+      const tempEl = document.createElement(displayAsBlock ? 'p' : 'span');
+      katex.render(source, tempEl, {
+        maxSize: MAX_SIZE,
+        maxExpand: MAX_EXPAND,
+        displayMode: displayAsBlock, // katex: true for display (block) mode, false for inline mode
+      });
+      target.replaceWith(tempEl);
+    } catch (error) {
+      displayError(target, error);
+    }
+  });
+}