Display a message if relays list is empty

central_frontend/src/routes/RelaysListRoute.tsx

@@ -9,15 +9,16 @@ import {
   TableHead,
   TableRow,
   Tooltip,
+  Typography,
 } from "@mui/material";
 import React from "react";
+import { useNavigate } from "react-router-dom";
 import { Device, DeviceApi, DeviceRelay, DeviceURL } from "../api/DeviceApi";
 import { RelayApi, RelaysStatus } from "../api/RelayApi";
 import { AsyncWidget } from "../widgets/AsyncWidget";
 import { BoolText } from "../widgets/BoolText";
 import { SolarEnergyRouteContainer } from "../widgets/SolarEnergyRouteContainer";
 import { TimeWidget } from "../widgets/TimeWidget";
-import { useNavigate } from "react-router-dom";
 
 export function RelaysListRoute(p: {
   homeWidget?: boolean;
@@ -86,6 +87,10 @@ function RelaysList(p: {
     navigate(DeviceURL(dev!));
   };
 
+  if (p.list.length === 0) {
+    return <Typography>There is no configured relay yet!</Typography>;
+  }
+
   return (
     <TableContainer component={Paper}>
       <Table sx={{ minWidth: 650 }}>