First version of integrating donatso/family-chart #185

src/util/previous-hook.ts

@@ -0,0 +1,9 @@
+import {useEffect, useRef} from 'react';
+
+export function usePrevious<T>(value: T): T | undefined {
+  const ref = useRef<T | undefined>(undefined);
+  useEffect(() => {
+    ref.current = value;
+  });
+  return ref.current;
+}