refactor(examples): switch examples from cra to nextjs

examples/nextjs/pages/UseUpdateNodeInternals/CustomNode.tsx

@@ -0,0 +1,33 @@
+import React, { memo, FC, useMemo, CSSProperties } from 'react';
+import { Handle, Position, NodeProps } from '@react-flow/core';
+
+const nodeStyles: CSSProperties = { padding: 10, border: '1px solid #ddd' };
+
+const CustomNode: FC<NodeProps> = ({ data }) => {
+  const handles = useMemo(
+    () =>
+      Array.from({ length: data.handleCount }, (x, i) => {
+        const handleId = `handle-${i}`;
+        return (
+          <Handle
+            key={handleId}
+            type='source'
+            position={Position.Right}
+            id={handleId}
+            style={{ top: 10 * i + data.handlePosition * 10 }}
+          />
+        );
+      }),
+    [data.handleCount, data.handlePosition]
+  );
+
+  return (
+    <div style={nodeStyles}>
+      <Handle type='target' position={Position.Left} />
+      <div>output handle count: {data.handleCount}</div>
+      {handles}
+    </div>
+  );
+};
+
+export default memo(CustomNode);

examples/nextjs/pages/UseUpdateNodeInternals/index.tsx

@@ -0,0 +1,128 @@
+import React, { useCallback, CSSProperties, MouseEvent } from 'react';
+
+import ReactFlow, {
+  NodeTypes,
+  addEdge,
+  useReactFlow,
+  ReactFlowProvider,
+  Node,
+  Connection,
+  Edge,
+  useUpdateNodeInternals,
+  Position,
+  useNodesState,
+  useEdgesState,
+} from '@react-flow/core';
+import CustomNode from './CustomNode';
+
+const initialHandleCount = 1;
+
+const initialNodes: Node[] = [
+  {
+    id: '1',
+    type: 'custom',
+    data: {
+      label: 'Node 1',
+      handleCount: initialHandleCount,
+      handlePosition: 0,
+    },
+    position: { x: 250, y: 5 },
+  },
+];
+
+const buttonWrapperStyles: CSSProperties = {
+  position: 'absolute',
+  right: 10,
+  top: 10,
+  zIndex: 10,
+};
+
+const nodeTypes: NodeTypes = {
+  custom: CustomNode,
+};
+
+let id = 5;
+const getId = (): string => `${id++}`;
+
+const UpdateNodeInternalsFlow = () => {
+  const [nodes, setNodes, onNodesChange] = useNodesState(initialNodes);
+  const [edges, setEdges, onEdgesChange] = useEdgesState([]);
+  const onConnect = (params: Edge | Connection) =>
+    setEdges((els) => addEdge(params, els));
+
+  const updateNodeInternals = useUpdateNodeInternals();
+  const { project } = useReactFlow();
+
+  const onPaneClick = useCallback(
+    (evt: MouseEvent) =>
+      setNodes((nds) =>
+        nds.concat({
+          id: getId(),
+          position: project({ x: evt.clientX, y: evt.clientY - 40 }),
+          data: { label: 'new node' },
+          targetPosition: Position.Left,
+          sourcePosition: Position.Right,
+        })
+      ),
+    [project, setNodes]
+  );
+
+  const toggleHandleCount = useCallback(() => {
+    setNodes((nds) =>
+      nds.map((node) => {
+        return {
+          ...node,
+          data: {
+            ...node.data,
+            handleCount: node.data?.handleCount === 1 ? 2 : 1,
+          },
+        };
+      })
+    );
+  }, [setNodes]);
+
+  const toggleHandlePosition = useCallback(() => {
+    setNodes((nds) =>
+      nds.map((node) => {
+        return {
+          ...node,
+          data: {
+            ...node.data,
+            handlePosition: node.data?.handlePosition === 0 ? 1 : 0,
+          },
+        };
+      })
+    );
+  }, [setNodes]);
+
+  const updateNode = useCallback(
+    () => updateNodeInternals('1'),
+    [updateNodeInternals]
+  );
+
+  return (
+    <ReactFlow
+      nodes={nodes}
+      edges={edges}
+      onNodesChange={onNodesChange}
+      onEdgesChange={onEdgesChange}
+      nodeTypes={nodeTypes}
+      onConnect={onConnect}
+      onPaneClick={onPaneClick}
+    >
+      <div style={buttonWrapperStyles}>
+        <button onClick={toggleHandleCount}>toggle handle count</button>
+        <button onClick={toggleHandlePosition}>toggle handle position</button>
+        <button onClick={updateNode}>update node internals</button>
+      </div>
+    </ReactFlow>
+  );
+};
+
+const WrappedFlow = () => (
+  <ReactFlowProvider>
+    <UpdateNodeInternalsFlow />
+  </ReactFlowProvider>
+);
+
+export default WrappedFlow;