# Managed by IssueSpec. Hand edits are welcome; keep the schema valid.
id: 9
title: Preview drawio
state: closed
author:
  name: k33g
  email: ph.charriere@gmail.com
createdAt: 2026-09-17T21:05:28.282Z
updatedAt: 2026-09-17T22:56:38.766Z
labels: []
body: |
  Preview draw.io diagrams in the workspace Preview tab.

  Implemented (2026-09-17):
  - `.drawio` / `.dio` (XML): rendered with the diagrams.net embed viewer
    (`embed.diagrams.net`, iframe, read-only lightbox) fed the XML locally over its
    postMessage protocol (`init` → `load`); the diagram is not uploaded. Rendered/Source
    toggle shows the XML. If the viewer does not answer within 8 s (isolated sandbox,
    no network), a notice appears and the Source view remains.
  - `.drawio.svg` / `.drawio.png`: plain images, shown by the image preview
    (`GET /api/raw`).
  - Trade-off recorded in docs/*/explanation/architecture.md: no offline renderer
    could be bundled (draw.io's viewer is not on npm, `mxgraph` is archived and lacks
    draw.io's shapes, `@markdown-viewer/drawio2svg` is GPL-3.0-only). Vendoring
    `viewer-static.min.js` (Apache-2.0, ~3 MB) is the future offline path.
tasks: []
comments: []