Details Markdown

An Obsidian plugin that renders Markdown inside native HTML <details>/<summary> blocks. Obsidian intentionally does not parse Markdown inside raw HTML blocks, so headings, lists, tables, internal links, and embeds inside a <details> fold show as literal text. This plugin fixes that: the body renders as real Markdown, visually identical to the same content written outside the block.

Scope: Rendering happens in Reading view. Live Preview (the editor) is not yet supported — there, the block shows Obsidian's native output. Support for Live Preview is planned for a future release.

Supported block shape

<details>
<summary>Summary text</summary>
### Any markdown body
- lists, [[internal links]], tables, embeds, code fences

blank lines in the body are supported (incl. inside code fences)
</details>

• <details> on its own line; an open attribute is allowed.
• <summary>...</summary> is optional and single-line, immediately after <details>.
• The body is everything up to </details>, on its own line.
• Unsupported, malformed, or unclosed blocks are left untouched (native behavior).
• Rendering the <summary> text itself as Markdown is out of scope.

Settings

A single toggle enables or disables the plugin. When off, Obsidian's native (literal) behavior returns with nothing left behind.

Installation

From the Community Plugins directory

Settings → Community plugins → Browse → search for "Details Markdown" → Install → Enable.

Manual

Copy manifest.json, main.js, and styles.css into <vault>/.obsidian/plugins/details-markdown/, then enable the plugin in Settings → Community plugins.

Development

npm install
npm test        # unit tests (parser)
npm run build   # typecheck + bundle -> main.js
npm run dev     # watch mode

Manual acceptance tests: test-vault-notes/Details Markdown Acceptance.md.

How it works

Obsidian ends an HTML block at the first blank line, so a <details> body with blank lines is split across several render sections and its tail "escapes" the fold. The plugin re-assembles blocks from raw source (never from rendered DOM):

• DetailsRangeScanner scans the full note text for supported block line ranges (fence-aware, nesting-aware; unclosed blocks yield no range).
• SectionRoleClassifier decides per rendered section: opening (starts a block) → render the whole body via MarkdownRenderer.render into the existing <details> element (native <summary> and open attribute preserved); fragment (escaped content inside a block) → hidden, but only once its block's opening actually rendered, so content can never be lost.
• A MarkdownRenderChild registered via ctx.addChild ties embeds/lifecycles to the note, so nothing leaks when the note closes. A registry reconciles edits: interior edits re-render the fold body in place; deleting a block boundary restores native output.

License

MIT