🖼️ Read iframe options from html (#1725)

Co-authored-by: Franklin Koch <franklinwkoch@gmail.com>

.changeset/stale-eels-confess.md

@@ -0,0 +1,5 @@
+---
+"myst-transforms": patch
+---
+
+Read iframe from html source

packages/myst-transforms/src/html.spec.ts

@@ -450,4 +450,22 @@ describe('Test reconstructHtmlTransform', () => {
       ],
     });
   });
+  test('iframe tags in html', async () => {
+    const mdast = {
+      type: 'root',
+      children: [{ type: 'html', value: '<iframe class="my-iframe" src="https://example.com" />' }],
+    };
+    htmlTransform(mdast);
+    expect(mdast).toEqual({
+      type: 'root',
+      children: [
+        {
+          type: 'iframe',
+          src: 'https://example.com',
+          class: 'my-iframe',
+          width: '100%',
+        },
+      ],
+    });
+  });
 });

packages/myst-transforms/src/html.ts

@@ -124,6 +124,12 @@ const defaultHtmlToMdastOptions: Record<keyof HtmlTransformOptions, any> = {
       if (node.properties.alt) attrs.alt = node.properties.alt;
       return h(node, 'image', attrs);
     },
+    iframe(h: H, node: any) {
+      const attrs = addClassAndIdentifier(node);
+      attrs.src = String(node.properties.src || '');
+      attrs.width = '100%';
+      return h(node, 'iframe', attrs);
+    },
     figure(h: H, node: any) {
       const attrs = addClassAndIdentifier(node);
       return h(node, 'container', attrs, all(h, node));