Diagrams as code

Standalone Graphviz DOT (.dot / .gv) and PlantUML (.puml / .plantuml) files get the same 3-mode preview (Editor / Split / Preview) as Markdown and Mermaid.

Rendering runs off-thread via the external dot and plantuml CLIs. Both rasterize to PNG natively, so there’s no headless browser, and results are cached by source hash so an unchanged diagram isn’t re-rendered. Zoom resizes the image.

PlantUML runs with PLANTUML_SECURITY_PROFILE=SANDBOX, so a diagram cannot !include local files or URLs. Export that variable yourself before starting Editora to choose another profile. The renderers also start without secret-looking environment variables.

Export

Export a diagram to SVG, PNG, or PDF with diagram.export (also on the preview’s right-click menu). File: Print Rendered Preview… (preview.print) prints it with a print preview. The PDF is sized by Graphviz or PlantUML, so the PDF page settings do not apply to it, and printed diagrams are always light.

Enabling

It’s on by default, self-gating on detection, so it stays inert until the tool is found. Install with your package manager, for example brew install graphviz plantuml. The toggle and the two tool paths live under Settings → Diagrams. Under each path a Detected line says whether the tool is there, for example dot: found (/usr/bin/dot) or plantuml: not found. Editora has no installer for these tools, so a missing one shows a How to install link to the Diagrams feature page instead of an Install… button. The paths are greyed while the preview is turned off.

For diagrams embedded in Markdown, see Mermaid.