Relation Graph

Link Data (`RGLink`)

RGLink is a runtime-derived, read-only relationship object.

It is generated from line data and provides convenient access to both endpoints plus render-related metadata.

1. Key Characteristics

You do not create RGLink directly.
You cannot update RGLink directly.
Update line/node data, then link data is recalculated automatically.

2. How to Get `RGLink`

const links = graphInstance.getLinks();
const link = graphInstance.getLinkByLineId('line-a-b');

3. Core Fields

lineId: string
line: RGLine
fromNode: RGNode
toNode: RGNode
totalLinesBetweenNodes: number
currentLineIndex: number
rgShouldRender?: boolean
rgCalcedVisibility?: boolean

4. Why `RGLink` Is Useful

RGLink is ideal when handling line events or building analysis logic:

find both endpoint node objects quickly
understand multi-line ordering between same node pair
read runtime visibility/render status

Example in line click event:

const onLineClick = (lineObject, linkObject, event) => {
  console.log('from:', linkObject.fromNode.id);
  console.log('to:', linkObject.toNode.id);
  console.log('index:', linkObject.currentLineIndex, '/', linkObject.totalLinesBetweenNodes);
};

5. Read-Only Data Flow

Correct update path:

update RGLine / node data
engine recalculates relation runtime state
RGLink reflects latest state

6. Practical Notes

Treat RGLink as computed relationship context.
For persistence/export, save node/line/fakeLine data, not RGLink.
Use RGLink primarily in event handlers, inspectors, and runtime analysis tools.

Link Data (RGLink)