drawio-diagram-hygiene

name	drawio-diagram-hygiene
description	Improve diagrams.net and draw.io diagrams by reducing overlap between connectors, boxes, and text, and by applying consistent routing, spacing, and label placement. Use when Codex edits `.drawio` or `mxfile` diagrams, reviews unreadable layouts, or needs to reroute connectors and clean labels without changing diagram meaning.

Drawio Diagram Hygiene

Keep the diagram's meaning stable while making it easier to scan. Prefer small XML edits that reduce collisions over large manual rearrangements.

Read references/layout-rules.md before editing when the diagram has more than a handful of edges or any long return path.

Workflow

1. Inspect the target .drawio / mxfile and identify the clutter source:
   • long back edges that cut across active content
   • edge labels sitting directly on busy connectors
   • nodes that are too short for wrapped text
   • notes or container titles placed in connector corridors
2. Preserve semantics first:
   • do not rename nodes, remove connections, or change the process flow unless the user asks
   • prefer rerouting, resizing, spacing, or label treatment changes
3. Normalize the layout:
   • keep one dominant flow direction per page, usually left-to-right
   • route exceptions and feedback loops on the outer perimeter, not through the middle of the diagram
   • keep sibling nodes aligned and leave visible gutters between them
4. Clean edges before moving nodes:
   • keep edgeStyle=orthogonalEdgeStyle unless the file already uses another deliberate style
   • add explicit waypoints for long or returning edges
   • add labelBackgroundColor=#FFFFFF;labelBorderColor=none;spacing=6; to labeled edges so text remains readable even when a crossing is unavoidable
   • shorten edge labels; move explanatory prose into a separate text note instead of a long edge label
5. Clean nodes only as needed:
   • increase box height before reducing font size
   • keep whiteSpace=wrap
   • if a connector still collides with text, move the text into its own note cell or reroute the connector around the box
6. Re-read the XML and sanity-check the riskiest edges:
   • look for waypoint y/x coordinates that run through another node's bounds
   • ensure any long perimeter route stays outside containers and title areas

Default Rules

• Leave roughly 40-80 px between sibling nodes when space allows.
• Reserve a top or bottom corridor for long return lines.
• Prefer node labels of 2-3 lines max; resize the box if the content is longer.
• Prefer short edge labels like extract, append row, or test only.
• Use separate note blocks for multi-clause explanations.

XML Patterns

Use this style fragment for labeled connectors:

style="edgeStyle=orthogonalEdgeStyle;rounded=0;jettySize=auto;html=1;strokeWidth=2;labelBackgroundColor=#FFFFFF;labelBorderColor=none;spacing=6;"

Use explicit perimeter waypoints for long back edges:

<Array as="points">
  <mxPoint x="1560" y="60" />
  <mxPoint x="425" y="60" />
</Array>

Output Expectations

• Keep diffs tight and readable.
• Mention the specific edges or nodes that were rerouted or resized.
• If the file is too dense to fix safely in one pass, say so and recommend splitting the diagram into multiple pages or lanes.