Add React MathType example

[culpen90]

Summary

• Add a standalone React MathType example under examples/react-mathtype.
• Store MathType formulas in a custom Lexical node so editor state remains authoritative.
• Bridge MathType insert/edit callbacks into Lexical updates and document the example setup.

Fixes #7806.

Validation

• corepack pnpm run typecheck from examples/react-mathtype
• corepack pnpm run build from examples/react-mathtype
• corepack pnpm exec prettier --check examples/react-mathtype
• corepack pnpm exec eslint examples/react-mathtype --no-error-on-unmatched-pattern

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Project	Deployment	Actions	Updated (UTC)
lexical	Ready	Preview, Comment	Jun 20, 2026 1:32pm
lexical-playground	Ready	Preview, Comment	Jun 20, 2026 1:32pm

[potatowagon]

Reviewed by Navi (Tater Thoughts Bobblehead) on behalf of @potatowagon.

Assessment: LGTM (pending CLA)

What this PR does: Adds a standalone examples/react-mathtype/ example showing WIRIS MathType integration with Lexical. Introduces MathTypeNode (DecoratorNode), a React context/provider for integration state, a toolbar plugin, and supporting utilities for MathML encode/decode and DOM import/export.

What I checked:

1. Code quality & architecture: Well-structured with clear separation of concerns — MathTypeData (pure MathML utilities), MathTypeGlobals (type declarations + window global accessor), MathTypeContext (React state management), MathTypeNode (Lexical node definition), and MathTypePlugin (integration bootstrap). Uses the modern $config() protocol with createState, $getState, $setState, and buildImportMap — follows the latest Lexical patterns from the 0.45.x API.

2. Correctness:

   • $commitFormula correctly handles both edit (existing nodeKey) and insert (range selection fallback → root append) paths.
   • DOM import uses priority 3 and checks for both .Wirisformula class and data-mathml attribute — good defensive conversion.
   • insertFormula override properly clears temporalImage and pendingNodeKeyRef after commit, preventing stale references.
   • encodeMathML/decodeMathML use WirisPlugin.MathML when available with a manual fallback using Unicode character substitutions — matches WIRIS's established encoding scheme.

3. Edge cases:

   • parseOptionalNumber guards against NaN, Infinity, and non-positive values.
   • MathTypeFormulaComponent double-click handler is gated on isEditable.
   • Integration cleanup in useEffect properly nulls integrationRef only if it still owns the reference (multi-mount safe).
   • contentEditable={true} on .mathtype-target div is intentional — it's the hidden proxy element that WIRIS requires for its generic integration API.

4. www compatibility: No concerns — this is a standalone example under examples/, no core library changes, no API surface modifications.

5. Security: The @wiris/mathtype-generic dependency loads from npm (^8.15.2). The example is self-contained; no new deps added to the core library. The MathML encode/decode uses character substitution (not eval/innerHTML injection).

6. CI status: Vercel previews pass, CLA is failing (first-time contributor needs to sign). No unit/integration/browser tests triggered since this is example-only.

Minor observations (non-blocking):

• The declare module '@wiris/mathtype-generic' in vite-env.d.ts is a minimal type stub — fine for an example, but contributors could later add a proper .d.ts if the example grows.
• No test files included, which is consistent with other standalone examples in the repo.

Verdict: Clean, well-typed MathType example that follows established Lexical patterns. Ready to approve once CLA is signed.

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[etrepum]

I'd recommend refactoring this for extensions so it can take advantage of newer features