Merge pull request #3742 from xyflow/feat/useconnection

Feat(react): add useConnection

examples/react/src/App/routes.ts

@@ -43,6 +43,7 @@ import CancelConnection from '../examples/CancelConnection';
 import InteractiveMinimap from '../examples/InteractiveMinimap';
 import UseOnSelectionChange from '../examples/UseOnSelectionChange';
 import NodeToolbar from '../examples/NodeToolbar';
+import UseConnection from '../examples/UseConnection';
 import UseNodesInitialized from '../examples/UseNodesInit';
 import UseNodesData from '../examples/UseNodesData';
 import UseHandleConnections from '../examples/UseHandleConnections';
@@ -254,6 +255,11 @@ const routes: IRoute[] = [
     path: 'update-node',
     component: UpdateNode,
   },
+  {
+    name: 'useConnection',
+    path: 'use-connection',
+    component: UseConnection,
+  },
   {
     name: 'useNodesInitialized',
     path: 'use-nodes-initialized',

examples/react/src/examples/UseConnection/index.tsx

@@ -0,0 +1,75 @@
+import { useCallback, useEffect } from 'react';
+import {
+  ReactFlow,
+  Background,
+  MiniMap,
+  Node,
+  addEdge,
+  ReactFlowProvider,
+  Edge,
+  useNodesState,
+  useEdgesState,
+  OnConnect,
+  useConnection,
+} from '@xyflow/react';
+
+const initialNodes: Node[] = [
+  {
+    id: '1',
+    type: 'input',
+    data: { label: 'Node 1' },
+    position: { x: 250, y: 5 },
+    className: 'light',
+  },
+  {
+    id: '2',
+    data: { label: 'Node 2' },
+    position: { x: 100, y: 100 },
+    className: 'light',
+  },
+  {
+    id: '3',
+    data: { label: 'Node 3' },
+    position: { x: 400, y: 100 },
+    className: 'light',
+  },
+];
+
+const initialEdges: Edge[] = [
+  { id: 'e1-2', source: '1', target: '2' },
+  { id: 'e1-3', source: '1', target: '3' },
+];
+
+const UseZoomPanHelperFlow = () => {
+  const [nodes, setNodes, onNodesChange] = useNodesState(initialNodes);
+  const [edges, setEdges, onEdgesChange] = useEdgesState(initialEdges);
+
+  const onConnect: OnConnect = useCallback((params) => setEdges((eds) => addEdge(params, eds)), []);
+  const connection = useConnection();
+
+  useEffect(() => {
+    console.log('connection', connection);
+  }, [connection]);
+
+  return (
+    <ReactFlow
+      nodes={nodes}
+      edges={edges}
+      onNodesChange={onNodesChange}
+      onEdgesChange={onEdgesChange}
+      onConnect={onConnect}
+      fitView
+    >
+      <Background />
+      <MiniMap />
+    </ReactFlow>
+  );
+};
+
+const WrappedFlow = () => (
+  <ReactFlowProvider>
+    <UseZoomPanHelperFlow />
+  </ReactFlowProvider>
+);
+
+export default WrappedFlow;

packages/react/src/hooks/useConnection.ts

@@ -0,0 +1,27 @@
+import { shallow } from 'zustand/shallow';
+
+import { useStore } from './useStore';
+import type { ReactFlowStore } from '../types/store';
+
+const selector = (s: ReactFlowStore) => ({
+  startHandle: s.connectionStartHandle,
+  endHandle: s.connectionEndHandle,
+  status: s.connectionStatus,
+  position: s.connectionStartHandle ? s.connectionPosition : null,
+});
+
+/**
+ * Hook for accessing the ongoing connection.
+ *
+ * @returns ongoing connection: startHandle, endHandle, status, position
+ */
+export function useConnection(): {
+  startHandle: ReactFlowStore['connectionStartHandle'];
+  endHandle: ReactFlowStore['connectionEndHandle'];
+  status: ReactFlowStore['connectionStatus'];
+  position: ReactFlowStore['connectionPosition'] | null;
+} {
+  const ongoingConnection = useStore(selector, shallow);
+
+  return ongoingConnection;
+}

packages/react/src/index.ts

@@ -25,6 +25,7 @@ export { default as useOnSelectionChange, type UseOnSelectionChangeOptions } fro
 export { default as useNodesInitialized, type UseNodesInitializedOptions } from './hooks/useNodesInitialized';
 export { useHandleConnections } from './hooks/useHandleConnections';
 export { useNodesData } from './hooks/useNodesData';
+export { useConnection } from './hooks/useConnection';
 export { useNodeId } from './contexts/NodeIdContext';
 
 export { applyNodeChanges, applyEdgeChanges, handleParentExpand } from './utils/changes';