react-diagrams/diagrams-demo-gallery/demos/demo-simple/index.tsx

import createEngine, { DiagramModel, DefaultNodeModel, DefaultLinkModel } from '@projectstorm/react-diagrams';
import * as React from 'react';
import { CanvasWidget } from '@projectstorm/react-canvas-core';
import { DemoCanvasWidget } from '../helpers/DemoCanvasWidget';

export default () => {
	//1) setup the diagram engine
	var engine = createEngine();

	//2) setup the diagram model
	var model = new DiagramModel();

	//3-A) create a default node
	var node1 = new DefaultNodeModel({
		name: 'Node 1',
		color: 'rgb(0,192,255)'
	});
	node1.setPosition(100, 100);
	let port1 = node1.addOutPort('Out');

	//3-B) create another default node
	var node2 = new DefaultNodeModel('Node 2', 'rgb(192,255,0)');
	let port2 = node2.addInPort('In');
	node2.setPosition(400, 100);

	// link the ports
	let link1 = port1.link<DefaultLinkModel>(port2);
	link1.getOptions().testName = 'Test';
	link1.addLabel('Hello World!');

	//4) add the models to the root graph
	model.addAll(node1, node2, link1);

	//5) load model into engine
	engine.setModel(model);

	//6) render the diagram!
	return (
		<DemoCanvasWidget>
			<CanvasWidget engine={engine} />
		</DemoCanvasWidget>
	);
};