如何防止每次父组件渲染时都渲染反应组件？

Question

I have a single TextField input on one form, the problem is that when I type on it the displayed/render of the value just typed has a kind of delay, and I want to prevent this.

Context: The TextField is label, name and id come from a state object called 'formInput' and they change their value every time a botton is pressed. The value of this single input is stored on a different state object called 'inputsValue' that changes inside a 'handleChange' function called on the onChange prop of the TextField.

The problem is that Suspicious: I made a "BouncyLetters" component and used it within a component that also renders a form, I use the BouncyLetters for the title of the form. When I remove this component from the page the typing display at normal speed. So I think disabling this from re-rendering always might solve the problem, idk. Thanks

Code:

 export const Contact = (props) => { const [formInput, setFormInput] = useState({input: 'name', label: 'Type name'}); ¿ const [inputsValue, setInputsValue] = useState({name: '', email: '', message: ''}); const handleClick = () => { switch (formInput.input) { case 'name': setFormInput({ input: 'email', label: 'type email' }); break; case 'email': setFormInput({ input: 'message', label: 'type message' }); break; case 'message': setFormInput({ input: 'name', label: 'type name' }); handleSubmission(); break; default: break; } } const handleChange = event => { setInputsValue({...inputsValue, [event.target.name]: event.target.value }); } const handleSubmission = event => { console.log('SUBMITTED CONTACT FORM') } return ( <form> <Grid container> <Grid item xs={12} sm={10}> <BouncyText /> </Grid> </Grid> <Grid container spacing={2}> <Grid item xs={12} id="contactFomrField"> <TextField fullWidth id={formInput.input} label={formInput.label} name={formInput.input} value={inputsValue[formInput.input]} onChange={handleChange} /> </Grid> </Grid> <Grid container justify="center" alignItems="center" > <Button onClick={handleClick} variant="outlined" color="primary" > { formInput.input?== 'message': 'Next': 'Send :)'} </Button> </form> ) }

Answer 1

handleClick() is a callback(declare in component) pass to child component, so it should be wrapped as useCallback() . otherwise, this callback is redeclare after rerender, so it's reference is different, make child component reconcile.

https://reactjs.org/docs/hooks-reference.html#usecallback