Merge pull request #4725 from xyflow/feat/use-handle-connection

add `useNodeConnections`, deprecate `useHandleConnections`

packages/react/src/hooks/useHandleConnections.ts

@@ -22,6 +22,7 @@ type useHandleConnectionsParams = {
  * Hook to check if a <Handle /> is connected to another <Handle /> and get the connections.
  *
  * @public
+ * @deprecated Use `useNodeConnections` instead.
  * @param param.type - handle type 'source' or 'target'
  * @param param.nodeId - node id - if not provided, the node id from the NodeIdContext is used
  * @param param.id - the handle id (this is only needed if the node has multiple handles of the same type)
@@ -31,18 +32,22 @@ type useHandleConnectionsParams = {
  */
 export function useHandleConnections({
   type,
-  id = null,
+  id,
   nodeId,
   onConnect,
   onDisconnect,
 }: useHandleConnectionsParams): HandleConnection[] {
+  console.warn(
+    '[DEPRECATED] `useHandleConnections` is deprecated. Instead use `useNodeConnections` https://reactflow.dev/api-reference/hooks/useNodeConnections'
+  );
+
   const _nodeId = useNodeId();
   const currentNodeId = nodeId ?? _nodeId;
 
   const prevConnections = useRef<Map<string, HandleConnection> | null>(null);
 
   const connections = useStore(
-    (state) => state.connectionLookup.get(`${currentNodeId}-${type}-${id}`),
+    (state) => state.connectionLookup.get(`${currentNodeId}-${type}${id ? `-${id}` : ''}`),
     areConnectionMapsEqual
   );
 

packages/react/src/hooks/useNodeConnections.ts

@@ -0,0 +1,69 @@
+import { useEffect, useMemo, useRef } from 'react';
+import {
+  Connection,
+  NodeConnection,
+  HandleType,
+  areConnectionMapsEqual,
+  handleConnectionChange,
+  errorMessages,
+} from '@xyflow/system';
+
+import { useStore } from './useStore';
+import { useNodeId } from '../contexts/NodeIdContext';
+
+const error014 = errorMessages['error014']();
+
+type UseNodeConnectionsParams = {
+  type?: HandleType;
+  handleId?: string;
+  nodeId?: string;
+  onConnect?: (connections: Connection[]) => void;
+  onDisconnect?: (connections: Connection[]) => void;
+};
+
+/**
+ * Hook to retrieve all edges connected to a node. Can be filtered by handle type and id.
+ *
+ * @public
+ * @param param.nodeId - node id - optional if called inside a custom node
+ * @param param.type - filter by handle type 'source' or 'target'
+ * @param param.handleId - filter by handle id (this is only needed if the node has multiple handles of the same type)
+ * @param param.onConnect - gets called when a connection is established
+ * @param param.onDisconnect - gets called when a connection is removed
+ * @returns an array with connections
+ */
+export function useNodeConnections({
+  type,
+  handleId,
+  nodeId,
+  onConnect,
+  onDisconnect,
+}: UseNodeConnectionsParams = {}): NodeConnection[] {
+  const _nodeId = useNodeId();
+  const currentNodeId = nodeId ?? _nodeId;
+
+  if (!currentNodeId) {
+    throw new Error(error014);
+  }
+
+  const prevConnections = useRef<Map<string, NodeConnection> | null>(null);
+
+  const connections = useStore(
+    (state) =>
+      state.connectionLookup.get(`${currentNodeId}${type ? (handleId ? `-${type}-${handleId}` : `-${type}`) : ''}`),
+    areConnectionMapsEqual
+  );
+
+  useEffect(() => {
+    // @todo dicuss if onConnect/onDisconnect should be called when the component mounts/unmounts
+    if (prevConnections.current && prevConnections.current !== connections) {
+      const _connections = connections ?? new Map();
+      handleConnectionChange(prevConnections.current, _connections, onDisconnect);
+      handleConnectionChange(_connections, prevConnections.current, onConnect);
+    }
+
+    prevConnections.current = connections ?? new Map();
+  }, [connections, onConnect, onDisconnect]);
+
+  return useMemo(() => Array.from(connections?.values() ?? []), [connections]);
+}

packages/react/src/hooks/useReactFlow.ts

@@ -238,7 +238,14 @@ export function useReactFlow<NodeType extends Node = Node, EdgeType extends Edge
         Array.from(
           store
             .getState()
-            .connectionLookup.get(`${nodeId}-${type}-${id ?? null}`)
+            .connectionLookup.get(`${nodeId}-${type}${id ? `-${id}` : ''}`)
+            ?.values() ?? []
+        ),
+      getNodeConnections: ({ type, handleId, nodeId }) =>
+        Array.from(
+          store
+            .getState()
+            .connectionLookup.get(`${nodeId}${type ? (handleId ? `-${type}-${handleId}` : `-${type}`) : ''}`)
             ?.values() ?? []
         ),
     };