項目の軽い整理

stateBox/useAllTrainDiagram.js

@@ -6,12 +6,15 @@ const initialState = {
 
 const AllTrainDiagramContext = createContext(initialState);
 
-export const useAllTrainDiagram = () => {
-  return useContext(AllTrainDiagramContext);
-};
+export const useAllTrainDiagram = () => useContext(AllTrainDiagramContext);
 
 export const AllTrainDiagramProvider = ({ children }) => {
   const [allTrainDiagram, setAllTrainDiagram] = useState();
+  const [keyList, setKeyList] = useState(); // 第二要素
+  useEffect(
+    () => allTrainDiagram && setKeyList(Object.keys(allTrainDiagram)),
+    [allTrainDiagram]
+  );
   const customData = {};
   useEffect(() => {
     fetch(
@@ -55,7 +58,7 @@ export const AllTrainDiagramProvider = ({ children }) => {
 
   return (
     <AllTrainDiagramContext.Provider
-      value={{ allTrainDiagram, setAllTrainDiagram }}
+      value={{ allTrainDiagram, setAllTrainDiagram,keyList }}
     >
       {children}
     </AllTrainDiagramContext.Provider>