refactor

web/src/useFetch.js

@@ -0,0 +1,15 @@
+import React from 'react';
+import axios from 'axios'
+
+export default function useFetch(url, defValue) {
+  const [value, setValue] = React.useState(defValue);
+
+  async function loadValue() {
+    setValue(await axios.get(url));
+  }
+  React.useEffect(() => {
+    loadValue();
+  }, [url]);
+
+  return value;
+}