Handle an input with React hooks
ReactjsReact HooksReactjs Problem Overview
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?
-
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}
Reactjs Solutions
Solution 1 - Reactjs
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}
</>;
Solution 2 - Reactjs
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>
</>
)
}
Solution 3 - Reactjs
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}
/>
Solution 4 - Reactjs
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>
);
...
}
Solution 5 - Reactjs
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>
)
}
}
Solution 6 - Reactjs
You may want to consider a form library like Formik