Handle an input with React hooks

Question

I found that there are several ways to handle user's text input with hooks. What is more preferable or proper way to handle an input with hooks? Which would you use?

1) The simplest hook to handle input, but more fields you have, more repetitive code you have to write.

const [username, setUsername] = useState('');
const [password, setPassword] = useState('');

events:

onChange={event => setPassword(event.target.value)}
onChange={event => setUsername(event.target.value)}

2) Similar to above example, but with dynamic key name

const [inputValues, setInputValues] = useState({
  username: '', password: ''
});

const handleOnChange = event => {
  const { name, value } = event.target;
  setInputValues({ ...inputValues, [name]: value });
};

event:

onChange={handleOnChange}

3) An alternative to useState, and as said on ReactJS docs, useReducer is usually preferable to useState.

const [inputValues, setInputValues] = useReducer(
  (state, newState) => ({ ...state, ...newState }),
  {username: '', password: ''}
);

const handleOnChange = event => {
  const { name, value } = event.target;
  setInputValues({ [name]: value });
};

event:

onChange={handleOnChange}

4) useCallback will return a memoized version of the callback that only changes if one of the dependencies has changed.

const [inputValues, setInputValues] = useState({ 
  username: '', password: '' 
});

const handleOnChange = useCallback(event => {
  const { name, value } = event.target;
  setInputValues({ ...inputValues, [name]: value });
});

event:

onChange={handleOnChange}

Answer 1

Thanks your answers and explanations from above: I implement these using Flask and React Hook with three button (start search data from server, update ag-grid table and cell data, and Save data to server) with Ag-Grid. I put in the version 106. https://github.com/peterhchen/900_ReactJS_Flask_FullStack

Answer 2

This is how i'm using right now:

const [inputValue, setInputValue] = React.useState("");

const onChangeHandler = event => {
   setInputValue(event.target.value);
};

<input
   type="text"
   name="name"
   onChange={onChangeHandler}
   value={inputValue}
/>

Answer 3

You may want to consider a form library like Formik

Answer 4

function App(){
    const [name, setName] = useState("");
    const [istrue, Setistrue] = useState(false);
    const [lastname,setLastname]=useState("");
    
    function handleclick(){
       Setistrue(true);
    }
    
    return(
        <div>
            {istrue ? <div> <h1>{name} {lastname}</h1> </div> : 
            <div>
                <input type="text" placeholder="firstname" name="name" onChange={e =>setName(e.target.value)}/>
                <input type="text" placeholder="lastname" name="lastname" onChange={e =>setLastname(e.target.value)}/>
               <button  type="submit" onClick={handleclick}>submit</button>
            </div>}
        </div>
    )
    
    }

}

Answer 5

How about writing a reusable function that returns the input value ... and the <input> itself:

 function useInput({ type /*...*/ }) {
   const [value, setValue] = useState("");
   const input = <input value={value} onChange={e => setValue(e.target.value)} type={type} />;
   return [value, input];
 }

That can then be used as:

 const [username, userInput] = useInput({ type: "text" });
 const [password, passwordInput] = useInput({ type: "text" });

 return <>
   {userInput} -> {username} <br />
   {passwordInput} -> {password}
 </>;

Answer 6

Yes you can handle react hooks with useState()

import React, {useState} from 'react'

export default () => {
    const [fName, setfName] = useState('');
    const [lName, setlName] = useState('');
    const [phone, setPhone] = useState('');
    const [email, setEmail] = useState('');

const submitValue = () => {
    const frmdetails = {
        'First Name' : fName,
        'Last Name' : lName,
        'Phone' : phone,
        'Email' : email
    }
    console.log(frmdetails);
}

return(
    <>
    <hr/>
    <input type="text" placeholder="First Name" onChange={e => setfName(e.target.value)} />
    <input type="text" placeholder="Last Name" onChange={e => setlName(e.target.value)} />
    <input type="text" placeholder="Phone" onChange={e => setPhone(e.target.value)} />
    <input type="text" placeholder="Email" onChange={e => setEmail(e.target.value)} />
    <button onClick={submitValue}>Submit</button>
    </>
    )
}

Answer 7

Here's how I do it (assuming your inputs must be inside a form):

I have a BasicForm component that I use.

It stores all the inputs state into an object into a single useState() call.

It passes via useContext() the inputs state along with an onChange() function and a function setInputInitialState() for the inputs to set their initial state when they are first mounted. It also passes onFocus, onBlur, and it has functions to validate fields which I'm not showing here to simplify the code.

This way I can easily create a form with as many inputs as I want, like:

<BasicForm
      isSubmitting={props.isSubmitting}
      submitAction={ (formState) =>
        props.doSignIn(formState) }
    >
      <TextInput
        type='email'
        label='Email'
        name='email'
        placeholder='Enter email...'
        required
      />
      <TextInput
        type='password'
        label='Password'
        name='password'
        placeholder='Enter password...'
        min={6}
        max={12}
        required
      />
      <SubmitButton
        label='Login'
      />
    </BasicForm>

BasicForm.js

import FormContext from './Parts/FormContext';

function BasicForm(props) {

  const [inputs, setInputs] = useState({});

  function onChange(event) {
    const newValue = event.target.value;
    const inputName = event.target.name;
    setInputs((prevState)=> {
      return({
        ...prevState,
        [inputName]: {
          ...prevState[inputName],
          value: newValue,
          dirty: true
        }
      });
    });
  }

  function setInputInitialState(
    inputName,
    label='This field ',
    type,
    initialValue = '',
    min = false,
    max = false,
    required = false) {

    const INITIAL_INPUT_STATE = {
      label: label,
      type: type,
      onFocus: false,
      touched: false,
      dirty: false,
      valid: false,
      invalid: false,
      invalidMsg: null,
      value: initialValue,
      min: min,
      max: max,
      required: required
    };

    setInputs((prevState) => {
      if (inputName in prevState) {
        return prevState;
      }
      return({
        ...prevState,
        [inputName]: INITIAL_INPUT_STATE
      });
    });

  }

return(
    <FormContext.Provider value={{
      onChange: onChange,
      inputs: inputs,
      setInputInitialState: setInputInitialState,
    }}>
      <form onSubmit={onSubmit} method='POST' noValidate>
        {props.children}
      </form>
    </FormContext.Provider>
  );
}

TextInput.js

The inputse use the useEffect() hook to set their initial state when they're mounted.

function TextInput(props) {

  const formContext = useContext(FormContext);

  useEffect(() => {
    console.log('TextInput useEffect...');
    formContext.setInputInitialState(
      props.name,
      props.label,
      props.type,
      props.initialValue,
      props.min,
      props.max,
      props.required
    );
  },[]);

  return(
      <input
        type={props.type}
        id={props.name}
        name={props.name}
        placeholder={props.placeholder}
        value={([props.name] in formContext.inputs) ?
                  formContext.inputs[props.name].value
                : props.initialValue || ''}
        onChange={formContext.onChange}
        onFocus={formContext.onFocus}
        onBlur={formContext.onBlur}
      >
      </input>
      </div>
      {([props.name] in formContext.inputs) ?
          formContext.inputs[props.name].invalidMsg && <div><span> {formContext.inputs[props.name].invalidMsg}</span></div>
        : null}
    </div>
  );

...
}