واکنش به ورودی کاربر بر اساس وضعیت در React

      async function handleFormSubmit(e) {
  e.preventDefault();
  disable(textarea);
  disable(button);
  show(loadingMessage);
  hide(errorMessage);
  try {
    await submitForm(textarea.value);
    show(successMessage);
    hide(form);
  } catch (err) {
    show(errorMessage);
    errorMessage.textContent = err.message;
  } finally {
    hide(loadingMessage);
    enable(textarea);
    enable(button);
  }
}

function handleTextareaChange() {
  if (textarea.value.length === 0) {
    disable(button);
  } else {
    enable(button);
  }
}

function hide(el) {
  el.style.display = 'none';
}

function show(el) {
  el.style.display = '';
}

function enable(el) {
  el.disabled = false;
}

function disable(el) {
  el.disabled = true;
}

function submitForm(answer) {
  // Pretend it's hitting the network.
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (answer.toLowerCase() === 'istanbul') {
        resolve();
      } else {
        reject(new Error('Good guess but a wrong answer. Try again!'));
      }
    }, 1500);
  });
}

let form = document.getElementById('form');
let textarea = document.getElementById('textarea');
let button = document.getElementById('button');
let loadingMessage = document.getElementById('loading');
let errorMessage = document.getElementById('error');
let successMessage = document.getElementById('success');
form.onsubmit = handleFormSubmit;
textarea.oninput = handleTextareaChange;
    

      export default function Form({
  status = 'empty'
}) {
  if (status === 'success') {
    return <h1>That's right!</h1>
  }
  return (
    <>
      <h2>City quiz</h2>
      <p>
        In which city is there a billboard that turns air into drinkable water?
      </p>
      <form>
        <textarea />
        <br />
        <button>
          Submit
        </button>
      </form>
    </>
  )
}
    

      export default function Form({
  // Try 'submitting', 'error', 'success':
  status = 'empty'
}) {
  if (status === 'success') {
    return <h1>That's right!</h1>
  }
  return (
    <>
      <h2>City quiz</h2>
      <p>
        In which city is there a billboard that turns air into drinkable water?
      </p>
      <form>
        <textarea disabled={
          status === 'submitting'
        } />
        <br />
        <button disabled={
          status === 'empty' ||
          status === 'submitting'
        }>
          Submit
        </button>
        {status === 'error' &&
          <p className="Error">
            Good guess but a wrong answer. Try again!
          </p>
        }
      </form>
      </>
  );
}
    

      import Form from './Form.js';

let statuses = [
  'empty',
  'typing',
  'submitting',
  'success',
  'error',
];

export default function App() {
  return (
    <>
      {statuses.map(status => (
        <section key={status}>
          <h4>Form ({status}):</h4>
          <Form status={status} />
        </section>
      ))}
    </>
  );
}
    

      const [answer, setAnswer] = useState('');
const [error, setError] = useState(null);
    

      const [isEmpty, setIsEmpty] = useState(true);
const [isTyping, setIsTyping] = useState(false);
const [isSubmitting, setIsSubmitting] = useState(false);
const [isSuccess, setIsSuccess] = useState(false);
const [isError, setIsError] = useState(false);
    

      const [answer, setAnswer] = useState('');
const [error, setError] = useState(null);
const [status, setStatus] = useState('typing'); // 'typing', 'submitting', or 'success'
    

      import { useState } from 'react';

export default function Form() {
  const [answer, setAnswer] = useState('');
  const [error, setError] = useState(null);
  const [status, setStatus] = useState('typing');

  if (status === 'success') {
    return <h1>That's right!</h1>
  }

  async function handleSubmit(e) {
    e.preventDefault();
    setStatus('submitting');
    try {
      await submitForm(answer);
      setStatus('success');
    } catch (err) {
      setStatus('typing');
      setError(err);
    }
  }

  function handleTextareaChange(e) {
    setAnswer(e.target.value);
  }

  return (
    <>
      <h2>City quiz</h2>
      <p>
        In which city is there a billboard that turns air into drinkable water?
      </p>
      <form onSubmit={handleSubmit}>
        <textarea
          value={answer}
          onChange={handleTextareaChange}
          disabled={status === 'submitting'}
        />
        <br />
        <button disabled={
          answer.length === 0 ||
          status === 'submitting'
        }>
          Submit
        </button>
        {error !== null &&
          <p className="Error">
            {error.message}
          </p>
        }
      </form>
    </>
  );
}

function submitForm(answer) {
  // Pretend it's hitting the network.
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      let shouldError = answer.toLowerCase() !== 'lima'
      if (shouldError) {
        reject(new Error('Good guess but a wrong answer. Try again!'));
      } else {
        resolve();
      }
    }, 1500);
  });
}
    

      export default function Picture() {
  return (
    <div className="background background--active">
      <img
        className="picture"
        alt="Rainbow houses in Kampung Pelangi, Indonesia"
        src="https://i.imgur.com/5qwVYb1.jpeg"
      />
    </div>
  );
}
    

      function handleFormSubmit(e) {
  e.preventDefault();
  if (editButton.textContent === 'Edit Profile') {
    editButton.textContent = 'Save Profile';
    hide(firstNameText);
    hide(lastNameText);
    show(firstNameInput);
    show(lastNameInput);
  } else {
    editButton.textContent = 'Edit Profile';
    hide(firstNameInput);
    hide(lastNameInput);
    show(firstNameText);
    show(lastNameText);
  }
}

function handleFirstNameChange() {
  firstNameText.textContent = firstNameInput.value;
  helloText.textContent = (
    'Hello ' +
    firstNameInput.value + ' ' +
    lastNameInput.value + '!'
  );
}

function handleLastNameChange() {
  lastNameText.textContent = lastNameInput.value;
  helloText.textContent = (
    'Hello ' +
    firstNameInput.value + ' ' +
    lastNameInput.value + '!'
  );
}

function hide(el) {
  el.style.display = 'none';
}

function show(el) {
  el.style.display = '';
}

let form = document.getElementById('form');
let editButton = document.getElementById('editButton');
let firstNameInput = document.getElementById('firstNameInput');
let firstNameText = document.getElementById('firstNameText');
let lastNameInput = document.getElementById('lastNameInput');
let lastNameText = document.getElementById('lastNameText');
let helloText = document.getElementById('helloText');
form.onsubmit = handleFormSubmit;
firstNameInput.oninput = handleFirstNameChange;
lastNameInput.oninput = handleLastNameChange;
    

      export default function EditProfile() {
  return (
    <form>
      <label>
        First name:{' '}
        <b>Jane</b>
        <input />
      </label>
      <label>
        Last name:{' '}
        <b>Jacobs</b>
        <input />
      </label>
      <button type="submit">
        Edit Profile
      </button>
      <p><i>Hello, Jane Jacobs!</i></p>
    </form>
  );
}
    

      function handleFormSubmit(e) {
  e.preventDefault();
  if (editButton.textContent === 'Edit Profile') {
    editButton.textContent = 'Save Profile';
    hide(firstNameText);
    hide(lastNameText);
    show(firstNameInput);
    show(lastNameInput);
  } else {
    editButton.textContent = 'Edit Profile';
    hide(firstNameInput);
    hide(lastNameInput);
    show(firstNameText);
    show(lastNameText);
  }
}

function handleFirstNameChange() {
  firstNameText.textContent = firstNameInput.value;
  helloText.textContent = (
    'Hello ' +
    firstNameInput.value + ' ' +
    lastNameInput.value + '!'
  );
}

function handleLastNameChange() {
  lastNameText.textContent = lastNameInput.value;
  helloText.textContent = (
    'Hello ' +
    firstNameInput.value + ' ' +
    lastNameInput.value + '!'
  );
}

function hide(el) {
  el.style.display = 'none';
}

function show(el) {
  el.style.display = '';
}

let form = document.getElementById('form');
let editButton = document.getElementById('editButton');
let firstNameInput = document.getElementById('firstNameInput');
let firstNameText = document.getElementById('firstNameText');
let lastNameInput = document.getElementById('lastNameInput');
let lastNameText = document.getElementById('lastNameText');
let helloText = document.getElementById('helloText');
form.onsubmit = handleFormSubmit;
firstNameInput.oninput = handleFirstNameChange;
lastNameInput.oninput = handleLastNameChange;
    

      let firstName = 'Jane';
let lastName = 'Jacobs';
let isEditing = false;

function handleFormSubmit(e) {
  e.preventDefault();
  setIsEditing(!isEditing);
}

function handleFirstNameChange(e) {
  setFirstName(e.target.value);
}

function handleLastNameChange(e) {
  setLastName(e.target.value);
}

function setFirstName(value) {
  firstName = value;
  updateDOM();
}

function setLastName(value) {
  lastName = value;
  updateDOM();
}

function setIsEditing(value) {
  isEditing = value;
  updateDOM();
}

function updateDOM() {
  if (isEditing) {
    editButton.textContent = 'Save Profile';
    // TODO: show inputs, hide content
  } else {
    editButton.textContent = 'Edit Profile';
    // TODO: hide inputs, show content
  }
  // TODO: update text labels
}

function hide(el) {
  el.style.display = 'none';
}

function show(el) {
  el.style.display = '';
}

let form = document.getElementById('form');
let editButton = document.getElementById('editButton');
let firstNameInput = document.getElementById('firstNameInput');
let firstNameText = document.getElementById('firstNameText');
let lastNameInput = document.getElementById('lastNameInput');
let lastNameText = document.getElementById('lastNameText');
let helloText = document.getElementById('helloText');
form.onsubmit = handleFormSubmit;
firstNameInput.oninput = handleFirstNameChange;
lastNameInput.oninput = handleLastNameChange;
    

      import { useState } from 'react';
export default function Picture() {
  const [isActive, setIsActive] = useState(false);
  let backgroundClassName = 'background';
  let pictureClassName = 'picture';
  if (isActive) {
    pictureClassName += ' picture--active';
  } else {
    backgroundClassName += ' background--active';
  }
  return (
    <div
      className={backgroundClassName}
      onClick={() => setIsActive(false)}
    >
      <img
        onClick={e => {
          e.stopPropagation();
          setIsActive(true);
        }}
        className={pictureClassName}
        alt="Rainbow houses in Kampung Pelangi, Indonesia"
        src="https://i.imgur.com/5qwVYb1.jpeg"
      />
    </div>
  );
}
    

      import { useState } from 'react';
export default function Picture() {
  const [isActive, setIsActive] = useState(false);
  if (isActive) {
    return (
      <div
        className="background"
        onClick={() => setIsActive(false)}
      >
        <img
          className="picture picture--active"
          alt="Rainbow houses in Kampung Pelangi, Indonesia"
          src="https://i.imgur.com/5qwVYb1.jpeg"
          onClick={e => e.stopPropagation()}
        />
      </div>
    );
  }
  return (
    <div className="background background--active">
      <img
        className="picture"
        alt="Rainbow houses in Kampung Pelangi, Indonesia"
        src="https://i.imgur.com/5qwVYb1.jpeg"
        onClick={() => setIsActive(true)}
      />
    </div>
  );
}
    

      import { useState } from 'react';

export default function EditProfile() {
  const [isEditing, setIsEditing] = useState(false);
  const [firstName, setFirstName] = useState('Jane');
  const [lastName, setLastName] = useState('Jacobs');

  return (
    <form onSubmit={e => {
      e.preventDefault();
      setIsEditing(!isEditing);
    }}>
      <label>
        First name:{' '}
        {isEditing ? (
          <input
            value={firstName}
            onChange={e => {
              setFirstName(e.target.value)
            }}
          />
        ) : (
          <b>{firstName}</b>
        )}
      </label>
      <label>
        Last name:{' '}
        {isEditing ? (
          <input
            value={lastName}
            onChange={e => {
              setLastName(e.target.value)
            }}
          />
        ) : (
          <b>{lastName}</b>
        )}
      </label>
      <button type="submit">
        {isEditing ? 'Save' : 'Edit'} Profile
      </button>
      <p><i>Hello, {firstName} {lastName}!</i></p>
    </form>
  );
}
    

      let firstName = 'Jane';
let lastName = 'Jacobs';
let isEditing = false;

function handleFormSubmit(e) {
  e.preventDefault();
  setIsEditing(!isEditing);
}

function handleFirstNameChange(e) {
  setFirstName(e.target.value);
}

function handleLastNameChange(e) {
  setLastName(e.target.value);
}

function setFirstName(value) {
  firstName = value;
  updateDOM();
}

function setLastName(value) {
  lastName = value;
  updateDOM();
}

function setIsEditing(value) {
  isEditing = value;
  updateDOM();
}

function updateDOM() {
  if (isEditing) {
    editButton.textContent = 'Save Profile';
    hide(firstNameText);
    hide(lastNameText);
    show(firstNameInput);
    show(lastNameInput);
  } else {
    editButton.textContent = 'Edit Profile';
    hide(firstNameInput);
    hide(lastNameInput);
    show(firstNameText);
    show(lastNameText);
  }
  firstNameText.textContent = firstName;
  lastNameText.textContent = lastName;
  helloText.textContent = (
    'Hello ' +
    firstName + ' ' +
    lastName + '!'
  );
}

function hide(el) {
  el.style.display = 'none';
}

function show(el) {
  el.style.display = '';
}

let form = document.getElementById('form');
let editButton = document.getElementById('editButton');
let firstNameInput = document.getElementById('firstNameInput');
let firstNameText = document.getElementById('firstNameText');
let lastNameInput = document.getElementById('lastNameInput');
let lastNameText = document.getElementById('lastNameText');
let helloText = document.getElementById('helloText');
form.onsubmit = handleFormSubmit;
firstNameInput.oninput = handleFirstNameChange;
lastNameInput.oninput = handleLastNameChange;