feat: open automatically

src/Rankings.tsx

@@ -1,4 +1,4 @@
-import { Dispatch, SetStateAction, useMemo, useState } from "react";
+import { Dispatch, SetStateAction, useEffect, useMemo, useState } from "react";
 import { ReactSortable, ReactSortableProps } from "react-sortablejs";
 import api, { baseUrl } from "./api";
 
@@ -268,6 +268,27 @@ export function MVP({ user, players }: PlayerInfoProps) {
   );
 }
 
+export default function Rankings() {
+  const [user, setUser] = useState<Player[]>([]);
+  const [players, setPlayers] = useState<Player[]>([]);
+  const [openTab, setOpenTab] = useState("Chemistry");
+
+  async function loadPlayers() {
+    const response = await fetch(`${baseUrl}player/list`, {
+      method: "GET",
+    });
+    const data = await response.json();
+    setPlayers(data as Player[]);
+  }
+
+  useMemo(() => {
+    loadPlayers();
+  }, []);
+
+  useEffect(() => {
+    user.length === 1 && openPage(openTab, "aliceblue");
+  }, [user]);
+
   function openPage(pageName: string, color: string) {
     // Hide all elements with class="tabcontent" by default */
     var i, tabcontent, tablinks;
@@ -290,24 +311,9 @@ function openPage(pageName: string, color: string) {
     activeButton.style.fontWeight = "bold";
     activeButton.style.opacity = "100%";
     document.body.style.backgroundColor = color;
+    setOpenTab(pageName);
   }
 
-export default function Rankings() {
-  const [user, setUser] = useState<Player[]>([]);
-  const [players, setPlayers] = useState<Player[]>([]);
-
-  async function loadPlayers() {
-    const response = await fetch(`${baseUrl}player/list`, {
-      method: "GET",
-    });
-    const data = await response.json();
-    setPlayers(data as Player[]);
-  }
-
-  useMemo(() => {
-    loadPlayers();
-  }, []);
-
   return (
     <>
       <SelectUser {...{ user, setUser, players, setPlayers }} />