chore(examples): add old api examples

example/src_oldapi/SaveRestore/Controls.tsx

@@ -0,0 +1,61 @@
+import React, { memo, useCallback, Dispatch, FC } from 'react';
+import { useZoomPanHelper, OnLoadParams, Elements, FlowExportObject } from 'react-flow-renderer';
+import localforage from 'localforage';
+
+localforage.config({
+  name: 'react-flow',
+  storeName: 'flows',
+});
+
+const flowKey = 'example-flow';
+
+const getNodeId = () => `randomnode_${+new Date()}`;
+
+type ControlsProps = {
+  rfInstance?: OnLoadParams;
+  setElements: Dispatch<React.SetStateAction<Elements<any>>>;
+};
+
+const Controls: FC<ControlsProps> = ({ rfInstance, setElements }) => {
+  const { transform } = useZoomPanHelper();
+
+  const onSave = useCallback(() => {
+    if (rfInstance) {
+      const flow = rfInstance.toObject();
+      localforage.setItem(flowKey, flow);
+    }
+  }, [rfInstance]);
+
+  const onRestore = useCallback(() => {
+    const restoreFlow = async () => {
+      const flow: FlowExportObject | null = await localforage.getItem(flowKey);
+
+      if (flow) {
+        const [x = 0, y = 0] = flow.position;
+        setElements(flow.elements || []);
+        transform({ x, y, zoom: flow.zoom || 0 });
+      }
+    };
+
+    restoreFlow();
+  }, [setElements, transform]);
+
+  const onAdd = useCallback(() => {
+    const newNode = {
+      id: `random_node-${getNodeId()}`,
+      data: { label: 'Added node' },
+      position: { x: Math.random() * window.innerWidth - 100, y: Math.random() * window.innerHeight },
+    };
+    setElements((els) => els.concat(newNode));
+  }, [setElements]);
+
+  return (
+    <div className="save__controls">
+      <button onClick={onSave}>save</button>
+      <button onClick={onRestore}>restore</button>
+      <button onClick={onAdd}>add node</button>
+    </div>
+  );
+};
+
+export default memo(Controls);