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Edge Class

Represents a directed relationship between two nodes.

Import​

import { Edge } from 'grafio';

Properties​

id​

readonly id: string

Unique identifier (auto-generated UUID).

sourceId​

readonly sourceId: string

The source node ID (where the edge starts).

targetId​

readonly targetId: string

The target node ID (where the edge ends).

type​

readonly type: string

The edge type (e.g., 'KNOWS', 'CONTAINS', 'AUTHOR_OF').

properties​

readonly properties: Readonly<Record<string, Primitive>>

The edge's key-value properties. Properties are deep-frozen for immutability.

Methods​

toJSON()​

toJSON(): EdgeData

Converts the edge to a JSON-serializable object.

Returns: EdgeData

interface EdgeData {
  id: string;
  sourceId: string;
  targetId: string;
  type: string;
  properties: Record<string, Primitive>;
}

Example​

const edge = await graph.addEdge(sourceId, targetId, 'KNOWS', { since: 2020 });

console.log(edge.id);        // 'uuid-xxxx-xxxx'
console.log(edge.sourceId);  // 'source-node-id'
console.log(edge.targetId);  // 'target-node-id'
console.log(edge.type);       // 'KNOWS'
console.log(edge.properties); // { since: 2020 }

// Serialize
const json = edge.toJSON();
/*
{
  id: 'uuid-xxxx-xxxx',
  sourceId: 'source-node-id',
  targetId: 'target-node-id',
  type: 'KNOWS',
  properties: { since: 2020 }
}
*/

Immutability​

Like Node properties, Edge properties are deep-frozen:

edge.properties.since = 2021; // TypeError: Cannot assign to read only property

Use Graph's edge property methods to modify:

await graph.updateEdgeProperty(edge.id, 'since', 2021);