v2 — react-ipynb-renderer

v2 kept the same public entry point as v1 — a single <IpynbRenderer> React component — but rebuilt almost everything underneath. It’s the version most v3 adopters are upgrading from.

Why v2 existed

v1’s markdown pipeline was built on markdown-it. That worked fine for plain prose cells but had two stubborn problems:

• Math extraction was fragile. $...$ / $$...$$ inside markdown ran through markdown-it before any math plugin could see it, and escaping rules interacted badly with code spans. The displayMath / inlineMath options existed in v1 but frequently didn’t produce the expected output.
• Raw HTML and markdown couldn’t mix cleanly. Jupyter notebooks routinely embed hand-written HTML inside markdown cells (figures with captions, collapsible sections, custom styling). markdown-it’s raw HTML handling punted on nested structures.

v2 moved to the unified / remark / rehype ecosystem — a tree-based pipeline where every stage operates on a real AST, not a string.

Feature timeline

2.0.x — the pipeline rewrite

The 2.0 headline was the markdown engine swap:

• markdown-it → remark + rehype. Markdown becomes a unist tree; remark plugins (for math, GFM, custom syntax) can rewrite nodes; then remark-rehype converts to a hast tree; rehype plugins finalise the HTML. This is the same stack used by MDX, by Docusaurus, and by the v3 @jupyter-kit/core markdown pipeline today.
• displayMath / inlineMath actually work. With math-node extraction happening at the remark stage, the math options produce consistent output for both KaTeX and MathJax.
• Option consolidation. Several v1 options that had overlapped or been superseded were merged or removed — the result was a smaller, more orthogonal prop surface.
• Error-cell rendering. Python tracebacks, IPython SyntaxError frames, kernel-death messages — all got dedicated rendering (background tint, preserved ANSI colours) instead of being dropped into the generic stream output box.

2.1.x — themes and polish

Notebooks started looking less like “raw Jupyter in a React app” and more like first-class UI:

• Four built-in themes: default, dark, darkbronco, dorkula. Selectable via a prop — the component loaded the matching CSS itself.
• Double-click-selects-source. Inside a code cell, a double click highlighted the entire source block, making copy-paste to a real Jupyter instance trivial.
• Empty-output cells hidden. Cells with no outputs stopped rendering an empty output box. Notebooks that had been re-authored (source cleared and not re-run) looked tidier without post-processing the JSON.

2.2.x — lifecycle and housekeeping

• onLoad callback — fired once the renderer finished its initial render, so parent apps could scroll-to-top or resize their layout without racing the async markdown pipeline.
• ref forwarding — useRef on <IpynbRenderer> exposed the underlying mount element. This was the first step toward imperative access for plugins/extensions, which became the RendererHandle API in v3.
• Added E2E (Playwright) tests, ESLint rules, and PR / issue templates. Not user-facing, but this is the maintenance baseline v3 inherited.

What v2 got right

• The unified pipeline. Carried directly into v3’s core unchanged.
• Theming as a concept. The idea that “pick a notebook chrome, separately pick a syntax theme” survived — v3 just exploded the implementation from one bundled CSS file into independently-installable packages.
• onLoad + ref. Still present in @jupyter-kit/react.

What v2 still couldn’t do

• React-only. Vue / Web Component users still had to reinvent.
• Math engines were bundled by default. A docs site with no math still paid the MathJax bundle cost.
• No editing or execution. v2 was a renderer, not an environment.

All three limitations drove the v3 reshuffling.

Where to find v2 docs

Archived alongside v1 at docs.walkframe.com/react-ipynb-renderer/history.

What carried over to v3

v2 feature	Status in v3
remark / rehype markdown pipeline	Unchanged, inside @jupyter-kit/core
onLoad callback	Unchanged, @jupyter-kit/react
ref forwarding	Unchanged, exposes richer RendererHandle
Built-in themes	Moved to @jupyter-kit/theme-<name> — one per chrome
Bundled KaTeX / MathJax	Opt-in plugins (@jupyter-kit/katex(-cdn), …/mathjax(-cdn))
syntaxTheme prop	Replaced by importing a syntax CSS file directly

Coming from v2? → Migration guide.