Forms as functional components with react

Question

If I want to make a functional component that will contain a form ,to login for example, and I want to contain the state in App component and Login will be its child, can I mutate the state in App using the form in Login child?

Answer 1

import React, {useState} from 'react';

function Submit() {

    const [inputField , setInputField] = useState({
        first_name: '',
        last_name: '',
        gmail: ''
    })

    const inputsHandler = (e) =>{
        setInputField( {[e.target.name]: e.target.value} )
    }

    const submitButton = () =>{
        alert(inputField.first_name)
    }

    return (
        <div>
            <input 
            type="text" 
            name="first_name" 
            onChange={inputsHandler} 
            placeholder="First Name" 
            value={inputField.first_name}/>

            <br/>

            <input 
            type="text" 
            name="last_name" 
            onChange={inputsHandler} 
            placeholder="First Name" 
            value={inputField.last_name}/>

            <br/>

            <input 
            type="gmail" 
            name="gmail" 
            onChange={inputsHandler} 
            placeholder="Gmail" 
            value={inputField.gmail}/>

            <br/>

            <button onClick={submitButton}>Submit Now</button>
        </div>
    )
}

export default Submit

Answer 2

Yes. Pass two props an object data and a method onChange to Login from App. data will set the values for the form in Login.

Fire onChange with updated form values if there is any change in Login form.

Handle it in App and update its state which will then flow down to Login as data.