Disable button on Form Submit in React

For some reason, my Sign In button does not become disabled when the form is submitted. Is there something obviously incorrect?

It is supposed to be disabled when processing a user’s sign in API request.

This is also not a result of a fast API, because even if I set the network speed to very slow, it does not become disabled at any point.

import React, { useRef, useState } from 'react';
import { Link, useNavigate } from 'react-router-dom';
import {
  Alert, Box, Card, TextField, Typography,
} from '@mui/material';
import LoadingButton from '@mui/lab/LoadingButton';
import { useAuth } from '../context/AuthContext';
import '../../pages/bg.css';

export default function SignInAuth() {
  const emailRef = useRef();
  const passwordRef = useRef();
  const [error, setError] = useState('');
  const [loading, setLoading] = useState(false);
  const navigate = useNavigate();
  const auth = useAuth();

  async function handleSubmit(e) {
    e.preventDefault();

    if (!emailRef.current.value) {
      return setError('Please enter an Email Address');
    }

    if (!passwordRef.current.value) {
      return setError('Please enter a password');
    }

    setLoading(true);
    setError('');

    fetch(
      `${process.env.REACT_APP_API_URL}auth/login`,
      {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify({
          Email: emailRef.current.value,
          Password: passwordRef.current.value,
        }),
      },
    ).then((response) => {
      if (response.ok) {
        auth.signin(emailRef.current.value);
        return navigate('/Dashboard');
      }
      // Response must be handled in a promise.
      return response.json().then((errorText) => { throw new Error(errorText.message); });
    }).then(setLoading(false)).catch((err) => {
      setError(err.message); // This comes from the returned error promise.
      // System throws error, and then error is set for the text.
    });
    return null;
  }

  const onSubmit = (e) => {
    handleSubmit(e);
  };

  const textFieldStyle = {
    width: '300px',
  };

  return (
    <Box sx={{
      zIndex: 1,
      minWidth: '200px',
      width: '450px',
    }}
    >
      <Card sx={{ p: '20px', borderRadius: '15px' }}>
        <Typography variant="h4" sx={{ fontWeight: 600, textAlign: 'center', mb: '8px' }}>Sign In</Typography>

        <form onSubmit={(e) => onSubmit(e)}>
          <Box sx={{ display: 'flex', flexDirection: 'column', alignItems: 'center' }}>
            {error && <Alert severity="error" sx={{ ...textFieldStyle, my: '10px' }}>{error}</Alert>}
            <TextField autoFocus margin="normal" inputRef={emailRef} type="email" id="email" label="Email" sx={textFieldStyle} />
            <TextField margin="normal" inputRef={passwordRef} type="password" id="password" label="Password" sx={textFieldStyle} />
            <LoadingButton
              sx={{ mt: '16px', mb: '4px', width: '150px' }}
              loading={loading}
              variant="contained"
              type="submit"
            >
              Sign In
            </LoadingButton>
          </Box>
        </form>
        <Typography variant="subtitle1" align="center" sx={{ mt: '10px' }}>
          <Link to="/forgot-password">Forgot Password?</Link>
        </Typography>
      </Card>
      <Box>
        <Typography variant="subtitle1" align="center" sx={{ mt: '10px' }}>
          Need an account?
          {' '}
          <Link to="/SignUp">Sign Up</Link>
        </Typography>
      </Box>
    </Box>
  );
}

>Solution :

According to the documentation, you must pass in a disabled prop to the LoadingButton component. Set it to be the same as your loading state.

<LoadingButton 
  sx={{ mt: '16px', mb: '4px', width: '150px' }} 
  loading={loading} 
  disabled={loading}
  variant="contained" 
  type="submit"
>
  Sign In
</LoadingButton>