office-viewer

Architecture spike for a standalone, read-only browser-based Office Open XML viewer built on @silurus/ooxml.

Spike scope

This repository currently contains a technical spike with an initial <office-viewer> custom-element wrapper.

Milestone 1 (minimal component shell and lifecycle baseline) is complete; the API remains experimental.

Included in this milestone:

• verified upstream API notes for @silurus/ooxml
• a raw integration harness under /demo
• representative DOCX, XLSX, and PPTX fixtures under /public/fixtures
• focused Vitest + WebdriverIO tests
• production-build asset checks and bundle-size notes
• first-pass OfficeViewerElement wrapper that delegates to the integration spike engine

Not included yet:

• the polished, stable public custom-element API
• common printing
• PDF support
• a public workerUrl option

Initial custom-element slice (experimental)

The package now exports an early wrapper for browser usage:

• OfficeViewerElement
• defineOfficeViewerElement()

Current wrapper behavior:

• delegates loading/reload/destroy to the existing OoxmlIntegrationSpike
• supports src, file-name, file-type, mode, and wasm-url attributes
• exposes load(), reload(), destroy(), and getSummary()
• exposes format-specific navigation methods: goToPage(), goToSheet(), goToSlide()
• supports request cancellation via load(source, { signal }) using AbortSignal
• dispatches loadstart, progress, ready, loaderror, pagechange, sheetchange, slidechange, and destroy events

This surface is intentionally provisional while the final public API is being validated.

Install

corepack enable
corepack prepare pnpm@latest --activate
pnpm install

Run the spike harness

pnpm dev

Then open:

• http://127.0.0.1:5173/demo/

The harness lets you:

• load sample DOCX/XLSX/PPTX fixtures by URL
• switch between worker and main mode
• load a local file
• destroy and reload the active viewer
• experiment with wasmUrl when you have a custom hosted WASM path

Test

pnpm test
pnpm build
pnpm test:build

Inspect the production build

pnpm preview

Then open:

• http://127.0.0.1:4173/demo/

Notes and findings

• Verified API notes: docs/ooxml-integration-notes.md
• Bundle and asset measurements: docs/bundle-size-spike.md

Known limitations

• The custom-element wrapper is an initial slice and may change before the stable release.
• The harness normalizes File, Blob, and Uint8Array inputs to ArrayBuffer because current upstream declarations type load(source) as string | ArrayBuffer.
• The spike verifies Vite 8 development/build behavior and a local static preview. It does not add custom worker hosting because upstream does not expose a public workerUrl.
• If a bundler does not preserve upstream new URL(..., import.meta.url) WASM resolution, copy the required *_parser_bg.wasm file into served assets and pass wasmUrl.