Was ist die Lösung für Formularvalidierungsprobleme in React JSX?-Fragen und Antworten zum chinesischen PHP-Netzwerk

Ich versuche, ein Validierungsformular in React zu erstellen, aber seit ich das Speichern von Benutzerregistrierungsdaten hinzugefügt habe, stoße ich auf viele Probleme.

import React, { useState } from "react";
import "./registerstyle.css";
import EyeIcon from "./EyeIcon.png";
import EyeIconHide from "./EyeIconHide.png";
import { signup } from "../../api/client";

function RegisterPage() {
  const [showPassword, setShowPassword] = useState(false);
  const [passwordVisible, setPasswordVisible] = useState(false);
  const [showConfirmPassword, setShowConfirmPassword] = useState(false);
  const [confirmPasswordVisible, setConfirmPasswordVisible] = useState(false);
  const [nameEmpty, setNameEmpty] = useState(false);
  const [confirmPasswordEmpty, setconfirmPasswordEmpty] = useState(false);
  const [emailEmpty, setEmailEmpty] = useState(false);
  const [passwordEmpty, setPasswordEmpty] = useState(false);
  const [newsletter, setNewsletter] = useState(false); // Aggiunto lo stato per la checkbox

  const [name, setName] = useState(null);
  const [email, setEmail] = useState(null);
  const [password, setPassword] = useState(null);
  const [cpass, setCpass] = useState(null);
  const user = { name: name, email: email, password: password, cpass: cpass };



  const handleShowPassword = () => {
    setShowPassword(!showPassword);
    setPasswordVisible(!passwordVisible);
  };

  const handleShowConfirmPassword = () => {
    setShowConfirmPassword(!showConfirmPassword);
    setConfirmPasswordVisible(!confirmPasswordVisible);
  };

  const handleFormSubmit = (e) => {
    e.preventDefault();

    // Verifica se i campi email e password sono vuoti
    if (!e.target.email.value) {
      setEmailEmpty(true);
      console.log("email True");
    } else {
      setEmailEmpty(false);
      console.log("email False");
    }

    if (!e.target.name.value) {
      setNameEmpty(true);
    } else {
      setNameEmpty(false);
    }

    if (!e.target.password.value) {
      setPasswordEmpty(true);
    } else {
      setPasswordEmpty(false);
    }

    if (!e.target.confirmPassword.value) {
      setconfirmPasswordEmpty(true);
    } else {
      setconfirmPasswordEmpty(false);
    }
  };

  const handleNewsletterChange = (e) => {
    setNewsletter(e.target.checked);
  }; // Funzione per gestire il cambiamento di stato della checkbox

  const passwordInputClass = passwordVisible ? "passwordVisible" : "";
  const confirmPasswordInputClass = confirmPasswordVisible ? "confirmPasswordVisible" : "";

  return (
    <div className="backgroundRegister">
      <div className="titleRegister" />
      <div className="breakRegister" />
      <div className="contlogRegister" />
      <div className="signIn" />
      <form className="formRegister" onSubmit={handleFormSubmit}>
        <label>
          {/* NAME */}
          <input type="text" name="name" placeholder="Name" onChange={(e) => { setName(e.target.value) }} required/>
        </label>
        {nameEmpty && (
          <div>
            <div className="alertCircleName" />
            <div className="FillThisName" />
            <div className="RedRectangleName" />
            <div className="nameError" />
          </div>
        )}
        <br />
        <label>
          {/* EMAIL */}
          <input type="email" name="email" placeholder="Email" onChange={(e) => { setEmail(e.target.value) }} required/>
        </label>
        {emailEmpty && (
          <div>
            <div className="alertCircleEmailRegister" />
            <div className="FillThisEmailRegister" />
            <div className="RedRectangleEmailRegister" />
            <div className="emailErrorRegister" />
          </div>
        )}
        <br />
        <label>
          {/* PASSWORD*/}
          <input
            type={showPassword ? "text" : "password"}
            name="password"
            placeholder="Password"
            className={passwordInputClass}
            onChange={(e) => { setPassword(e.target.value) }}
          />
          <img
            src={passwordVisible ? EyeIconHide : EyeIcon}
            alt="eye-icon"
            className="eyeIconRegister1"
            onClick={() => {
              handleShowPassword();
            }}
          />
        </label>
        {passwordEmpty && (
          <div>
            <div className="alertCirclePasswordRegister" />
            <div className="FillThisPasswordRegister" />
            <div className="RedRectanglePasswordRegister" />
            <div className="passwordErrorRegister" />
          </div>
        )}
        <br />
        <label>
          {/* CONFIRM PASSWORD */}
          <input
            type={showConfirmPassword ? "text" : "password"}
            name="confirmPassword"
            placeholder="Confirm Password"
            className={confirmPasswordInputClass}
            onChange={(e) => { setCpass(e.target.value) }}
          />
          <img
            src={confirmPasswordVisible ? EyeIconHide : EyeIcon}
            alt="eye-icon"
            className="eyeIconRegister2"
            onClick={() => {
              handleShowConfirmPassword();
            }}
          />
        </label>
        {confirmPasswordEmpty && (
          <div>
            <div className="alertCircleConfirmPassword" />
            <div className="FillThisConfirmPassword" />
            <div className="RedRectangleConfirmPassword" />
            <div className="confirmPasswordError" />
          </div>
        )}
        <br />
        <label> {/* NEWSLETTER */}
          <input type="checkbox" name="newsletter" checked={newsletter} onChange={handleNewsletterChange} />
        </label>
        <span className="newsletter">Send me newsletters, tricks and updates. </span>
        <br />
        <input type="submit" value="SIGN IN" className="signInButton" onClick={(e) => {
          e.preventDefault();
          signup(user);
          handleFormSubmit(e);
        }}/>
      </form>
      <div className="registerSign">
        Already have an account? <a href="" className="colorRegister">Login now</a>
      </div>
    </div>

  );
}

export default RegisterPage;

Dies ist der Registrierungscode:

import axios from "axios";

// const client = axios.create({
//   baseURL: "http://localhost:9000", // o l'endpoint del vostro backend
//   headers: {
//     "Content-Type": "application/json",
//     //     "Authorization": "Bearer " + localStorage.getItem("token")
//   }
// });

// export default client;


async function signup(user) {
  const newUser = JSON.stringify(user);
  console.log("sono dentro la funzione");

  try {
    return await axios.post("http://localhost:3000/signup", newUser);
  } catch (err) {
    if (err.response) {
      return err.response.data;
    } else {
      console.log("Errore:", err.message);
    }
  }
};

async function login(user) {
  const newUser = JSON.stringify(user);
  console.log("sono dentro");

  try {
    return await axios.post("http://localhost:3000/login", newUser);
    //return await axios.post("http://localhost:3000/login",)
  } catch (err) {
    if (err.response) {
      return err.response.data;
    } else {
      console.log("Errore:", err.message);
    }
  }
};

async function loginOld(credentials) {
  const loginData = JSON.stringify(credentials);
  await axios.post("http://localhost:3000/login", loginData);
};

export { signup, login };

Was ich erwartete, wenn die Felder beim Klicken auf die Schaltfläche leer blieben, war, dass sie aus dem von mir erstellten Bild auftauchen würden, um die Felder zu umkreisen, die leer gelassen wurden. Manchmal kommt es zu einem Fehler wie diesem:

TypeError: Cannot read properties of undefined (reading 'value')
    at handleFormSubmit (http://localhost:3000/main.7b4752724621de0f0bc6.hot-update.js:66:25)
    at onClick (http://localhost:3000/main.7b4752724621de0f0bc6.hot-update.js:387:11)
    at HTMLUnknownElement.callCallback (http://localhost:3000/static/js/bundle.js:14655:18)
    at Object.invokeGuardedCallbackDev (http://localhost:3000/static/js/bundle.js:14699:20)
    at invokeGuardedCallback (http://localhost:3000/static/js/bundle.js:14756:35)
    at invokeGuardedCallbackAndCatchFirstError (http://localhost:3000/static/js/bundle.js:14770:29)
    at executeDispatch (http://localhost:3000/static/js/bundle.js:18914:7)
    at processDispatchQueueItemsInOrder (http://localhost:3000/static/js/bundle.js:18940:11)
    at processDispatchQueue (http://localhost:3000/static/js/bundle.js:18951:9)
    at dispatchEventsForPlugins (http://localhost:3000/static/js/bundle.js:18960:7)```

I'm desperate and don't really know where to put my hands.