Page 341 - MDP2022-3

}

export default Announcement;

import {

Button,
Dialog,

DialogActions,
DialogContent,
DialogContentText,

DialogTitle,
TextField,
} from "@material-ui/core";

import React, { useState } from "react";
import { useAuthState } from "react-firebase-hooks/auth";

import { useRecoilState } from "recoil";
import { auth, db } from "../firebase";
import { joinDialogAtom } from "../utils/atoms";

function JoinClass() {

const [open, setOpen] = useRecoilState(joinDialogAtom);
const [user, loading, error] = useAuthState(auth);
const [classId, setClassId] = useState("");

const handleClose = () => {

setOpen(false);
};

const joinClass = async () => {
try {

// check if class exists
const classRef = await db.collection("classes").doc(classId).get();
if (!classRef.exists) {

return alert(`Class doesn't exist, please provide correct ID`);
}

const classData = await classRef.data();
// add class to user
const userRef = await db.collection("users").where("uid", "==", user.uid);