Delete Edge on Drop

In this example we are showing how to delete an edge by using the onReconnect, onReconnectStart and onReconnectEnd handlers. If you drag an existing edge and drop it on the pane, it gets deleted from the edges array.


import React, { useCallback, useRef } from 'react';
import {
  Background,
  ReactFlow,
  useNodesState,
  useEdgesState,
  Controls,
  reconnectEdge,
  addEdge,
} from '@xyflow/react';
 
import '@xyflow/react/dist/style.css';
 
 
const initialNodes = [
  {
    id: '1',
    type: 'input',
    data: { label: 'Node A' },
    position: { x: 250, y: 0 },
  },
  {
    id: '2',
    data: { label: 'Node B' },
    position: { x: 100, y: 200 },
  },
  {
    id: '3',
    data: { label: 'Node C' },
    position: { x: 350, y: 200 },
  },
];
 
const initialEdges = [
  { id: 'e1-2', source: '1', target: '2', label: 'reconnectable edge' },
];
 
const DeleteEdgeDrop = () => {
  const edgeReconnectSuccessful = useRef(true);
  const [nodes, , onNodesChange] = useNodesState(initialNodes);
  const [edges, setEdges, onEdgesChange] = useEdgesState(initialEdges);
  const onConnect = useCallback(
    (params) => setEdges((els) => addEdge(params, els)),
    [],
  );
 
  const onReconnectStart = useCallback(() => {
    edgeReconnectSuccessful.current = false;
  }, []);
 
  const onReconnect = useCallback((oldEdge, newConnection) => {
    edgeReconnectSuccessful.current = true;
    setEdges((els) => reconnectEdge(oldEdge, newConnection, els));
  }, []);
 
  const onReconnectEnd = useCallback((_, edge) => {
    if (!edgeReconnectSuccessful.current) {
      setEdges((eds) => eds.filter((e) => e.id !== edge.id));
    }
 
    edgeReconnectSuccessful.current = true;
  }, []);
 
  return (
    <ReactFlow
      nodes={nodes}
      edges={edges}
      onNodesChange={onNodesChange}
      onEdgesChange={onEdgesChange}
      snapToGrid
      onReconnect={onReconnect}
      onReconnectStart={onReconnectStart}
      onReconnectEnd={onReconnectEnd}
      onConnect={onConnect}
      fitView
      attributionPosition="top-right"
      style={{ backgroundColor: "#F7F9FB" }}
      >
        <Controls />
        <Background />
      </ReactFlow>
  
  );
};
 
export default DeleteEdgeDrop;